2021/07/12 更新

写真a

カワハラ ノブユキ
河原 伸幸
KAWAHARA Nobuyuki
所属
自然科学学域 教授
職名
教授
外部リンク

学位

  • 博士(工学) ( 神戸大学 )

研究キーワード

  • レーザ計測

  • 内燃機関

  • 燃焼

  • 熱工学

  • thermodynamics

研究分野

  • ものづくり技術(機械・電気電子・化学工学) / 熱工学

  • フロンティア(航空・船舶) / 船舶海洋工学

経歴

  • 岡山大学   自然科学学域   教授

    2021年4月 - 現在

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  • 岡山大学   研究教授

    2018年11月 - 2021年3月

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  • - 岡山大学自然科学研究科 准教授

    2004年

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  • - Associate Professor,Graduate School of Natural Science and Technology,Okayama University

    2004年

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  • Researcher,1997-1999 Postdoctral Research Fellow of JSPS

    1997年 - 1999年

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  • 1997-1999 日本学術振興会 特別研究員(PD) 研究員

    1997年 - 1999年

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  • 1997-1998 ドイツエアランゲン大学 客員研究員 未設定

    1997年 - 1998年

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▼全件表示

所属学協会

 

論文

  • End-gas autoignition characteristics of PREMIER combustion in a pilot fuel-ignited dual-fuel biogas engine 査読

    Berenjestanaki Alireza Valipour, Kawahara Nobuyuki, Tsuboi Kazuya, Tomita Eiji

    FUEL   254   2019年10月

  • Differences between PREMIER combustion in a natural gas spark-ignition engine and knocking with pressure oscillations 査読

    Kawahara Nobuyuki, Kim Yungjin, Wadahama Hisashi, Tsuboi Kazuya, Tomita Eiji

    PROCEEDINGS OF THE COMBUSTION INSTITUTE   37 ( 4 )   4983 - 4991   2019年

  • 後方散乱X線を用いた層流予混合火炎の温度分布と化学状態の計測 査読

    櫻井浩, 河原伸幸, 冨田栄二, 鈴木宏輔, 伊藤真義, 櫻井吉晴

    日本エネルギー学会機関紙えねるみくす   97 ( 4 )   2018年4月

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  • Numerical Investigation of Natural Gas-Diesel Dual Fuel Engine with End Gas Ignition

    Apoorv Talekar, Ming Chia Lai, Eiji Tomita, Nobuyuki Kawahara, Ke Zeng, Bo Yang

    SAE Technical Papers   2018-April   2018年1月

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    © 2018 SAE International. All Rights Reserved. The present study helps to understand the local combustion characteristics of PREmixed Mixture Ignition in the End-gas Region (PREMIER) combustion mode while using increasing amount of natural gas as a diesel substitute in conventional CI engine. In order to reduce NOx emission and diesel fuel consumption micro-pilot diesel injection in premixed natural gas-air mixture is a promising technique. New strategy has been employed to simulate dual fuel combustion which uses well established combustion models. Main focus of the simulation is at detection of an end gas ignition, and creating an unified modeling approach for dual fuel combustion. In this study G-equation flame propagation model is used with detailed chemistry in order to detect end-gas ignition in overall low temperature combustion. This combustion simulation model is validated using comparison with experimental data for dual fuel engine.

    DOI: 10.4271/2018-01-0199

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  • Characterisation of DME-HCCI combustion cycles for formaldehyde and hydroxyl UV-vis absorption

    Ulugbek Azimov, Nearchos Stylianidis, Nobuyuki Kawahara, Eiji Tomita

    FUEL   210   578 - 591   2017年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    We investigated time-resolved ultraviolet-visible (UV-vis) light absorbance to identify the formation behaviour of formaldehyde (HCHO) and hydroxyl (OH) within the wavelength range of 280-400 nm in a homogeneous charge compression ignition (HCCI) engine fuelled with dimethyl ether (DME). The time-resolved HCHO and OH profiles at different initial pressures showed that HCHO absorbance increased in the low-temperature reaction (LTR) and thermal-ignition preparation (TIP) regions and decreased gradually as the combustion approached the high-temperature reaction (HTR) region. At higher intake pressures, HCHO absorbance decreased and OH absorbance increased. The time-resolved absorbance spectra of HCHO, with peaks at 316, 328, 340, and 354 nm for all combustion cycles, were evaluated and it was found that average absorption at 328 nm was slightly higher than at 316, 340, and 354 nm. For knocking combustion cycles, the absorbance of HCHO in the LTR region was high for cycles with low knock intensity and low for cycles with high knock intensity, showing a high level of OH absorbance. Chemical kinetics analyses showed that for different fuel/oxidiser ratios, initial O-2 concentration and intake temperature had no effect on in-cylinder temperatures in the LTR or TIP regions. However, they did have significant effects on HTR combustion. In-cylinder temperature in the LTR region had less effect on HCHO and H2O2 formation than pressure.

    DOI: 10.1016/j.fuel.2017.09.003

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  • Improvement of thermal efficiency and reduction of NOx emissions by burning a controlled jet plume in high-pressure direct-injection hydrogen engines

    Yasuo Takagi, Hiroki Mori, Yuji Mihara, Nobuyuki Kawahara, Eiji Tomita

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   42 ( 41 )   26114 - 26122   2017年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    A new combustion process called the Plume Ignition Combustion Concept (PCC), in which the plume tail of the hydrogen jet is spark-ignited immediately after the completion of fuel injection to accomplish combustion of a rich mixture has been proposed by the authors. This PCC combustion process markedly reduces nitrogen oxides (NOx) emissions in the high-output region while maintaining high levels of thermal efficiency and power. On the other hand, as burning lean mixture of fuel and air is the conventional way to improve thermal efficiency and reduce NOx, a high lambda premixed mixture of hydrogen and air formed by injecting hydrogen in the early stage of the compression stroke has been used in direct injection hydrogen engines. It was recently reported, however, that this mixture condition does not always offer expected improved thermal efficiency under even lean mixture conditions by increasing unburned hydrogen emissions caused by incomplete flame propagation in the non-uniform and extremely lean portion of the mixture. In this study, the effect of retarding the injection timing to late in the compression stroke but slightly advanced from original PCC was examined as a way of reducing unburned hydrogen emissions and improving thermal efficiency. These effects result from a centroidal axially stratified mixture that positions a fairly rich. charge near the spark plug. This stratified mixture is presumably effective in reducing incomplete flame propagation thought to be the cause of unburned hydrogen emissions and also promoting increasing burning velocity of the mixture that improve thermal efficiency. Finally, this research is characterized by measuring the hydrogen fuel concentration at the point and the time of spark ignition quantitatively by spark-induced breakdown spectroscopy in order to identify the changes in mixture ratio mentioned above caused by the parameters involved. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2017.08.015

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  • Chemical kinetics and CFD analysis of supercharged micro-pilot ignited dual-fuel engine combustion of syngas

    Nearchos Stylianidis, Ulugbek Azimov, Alireza Maheri, Eiji Tomita, Nobuyuki Kawahara

    FUEL   203   591 - 606   2017年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    A comprehensive chemical kinetics and computational fluid-dynamics (CFD) analysis were performed to evaluate the combustion of syngas derived from biomass and coke-oven solid feedstock in a micro-pilot ignited supercharged dual-fuel engine under lean conditions. The developed syngas chemical kinetics mechanism was validated by comparing ignition delay, in-cylinder pressure, temperature and laminar flame speed predictions against corresponding experimental and simulated data obtained by using the most commonly used chemical kinetics mechanisms developed by other authors. Sensitivity analysis showed that reactivity of syngas mixtures was found to be governed by H-2 and CO chemistry for hydrogen concentrations lower than 50% and mostly by H-2 chemistry for hydrogen concentrations higher than 50%. In the mechanism validation, particular emphasis is placed on predicting the combustion under high pressure conditions. For high hydrogen concentration in syngas under high pressure, the reactions HO2 + HO2 = H2O2 + O-2 and H2O2 + H = H-2 + HO2 were found to play important role in in-cylinder combustion and heat production. The rate constants for H2O2 + H = H-2 + HO2 reaction showed strong sensitivity to high-pressure ignition times and has considerable uncertainty. Developed mechanism was used in CFD analysis to predict in-cylinder combustion of syngas and results were compared with experimental data. Crank angle-resolved spatial distribution of in-cylinder spray and combustion temperature was obtained. The constructed mechanism showed the closest prediction of combustion for both biomass and cokeoven syngas in a micro-pilot ignited supercharged dual-fuel engine. (C) 2017 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.fuel.2017.04.125

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  • High-speed visualization of fuel spray impingement in the near-wall region using a DISI injector

    N. Kawahara, K. Kintaka, E. Tomita

    SELECTED PAPERS FROM THE 31ST INTERNATIONAL CONGRESS ON HIGH-SPEED IMAGING AND PHOTONICS   10328   2017年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    We used a multi-hole injector to spray isooctane under atmospheric conditions and observed droplet impingement behaviors. It is generally known that droplet impact regimes such as splashing, deposition, or bouncing are governed by the Weber number. However, owing to its complexity, little has been reported on microscopic visualization of poly-dispersed spray. During the spray impingement process, a large number of droplets approach, hit, then interact with the wall. It is therefore difficult to focus on a single droplet and observe the impingement process. We solved this difficulty using highspeed microscopic visualization. The spray/wall interaction processes were recorded by a high-speed camera (Shimadzu HPV-X2) with a long-distance microscope. We captured several impinging microscopic droplets. After optimizing the magnification and frame rate, the atomization behaviors, splashing and deposition, were recorded. Then, we processed the images obtained to determine droplet parameters such as the diameter, velocity, and impingement angle. Based on this information, the critical threshold between splashing and deposition was investigated in terms of the normal and parallel components of the Weber number with respect to the wall. The results suggested that, on a dry wall, we should set the normal critical Weber number to 300.

    DOI: 10.1117/12.2270691

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  • Spark discharge ignition process in a spark-ignition engine using a time series of spectra measurements

    Nobuyuki Kawahara, Shota Hashimoto, Eiji Tomita

    PROCEEDINGS OF THE COMBUSTION INSTITUTE   36 ( 3 )   3451 - 3458   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    The spark discharge ignition process was investigated using simultaneous temperature measurements of the spark discharges and the initial flame kernel. We were able for the first time to measure a time series of emission spectra from the spark discharge and initial flame kernel inside a spark-ignition engine using a spectrometer coupled with a spark plug and optical fiber. The plasma vibrational temperature of the spark discharge can be measured using time series emission spectra from the electrically excited CN* violet band system. The gas rotational temperature of the initial flame kernel can also be measured using emission spectra from OH* radicals (P and R branches). Simultaneously, visualization of the spark discharge and a time series of emission spectra inside a spark-ignition engine were performed under homogeneous mixture conditions, to eliminate the effects of stratification of temperature and mixture concentrations around the spark plug. We discuss thermal energy transfer from the spark discharge to the combustible mixture. The main conclusions that can be drawn from this study are as follows. CN* emission can be detected from the spark discharge, visualized using a high-speed camera during the arc discharge phase. Our results confirmed that the plasma temperature of the spark discharge was nearly 6800 K and that thermal energy was transferred from the spark plasma channel to the combustible mixture. The gas temperature of the initial flame kernel approached that of the adiabatic flame temperature. (C) 2016 by The Combustion Institute. Published by Elsevier Inc.

    DOI: 10.1016/j.proci.2016.08.029

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  • Extension of PREMIER combustion operation range using split micro pilot fuel injection in a dual fuel natural gas compression ignition engine: A performance-based and visual investigation

    Cagdas Aksu, Nobuyuki Kawahara, Kazuya Tsuboi, Morio Kondo, Eiji Tomita

    FUEL   185   243 - 253   2016年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    The effects of split pilot fuel injection on engine performance and PREmixed Mixture Ignition in the End Gas Region (PREMIER) combustion characteristics were investigated in a single-cylinder dual-fuel natural gas engine ignited with diesel fuel. In particular, the effect of second spray timing on combustion mode was examined. PREMIER combustion was observed in a wider range of operating conditions with split injection strategy compared to single injection strategy. We determined that it was possible to both decelerate heat release and suppress knocking to PREMIER combustion, and accelerate heat release and promote normal combustion to PREMIER combustion, with suitable second injection timing. The maximum of thermal efficiency of PREMIER combustion operation with split injection was close to the results obtained with knocking operation. In-cylinder images showed that split injection strategy advances or retards the progress of combustion by controlling the size and rate of growth of flame kernels, depending on the timing of the second injection. The combustion progress is earlier when the pilot fuel delivered during the first injection autoignites during the second injection. Kernel growth and the final size were adversely affected when the second injection was initiated after pilot fuel autoignition. (C) 2016 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.fuel.2016.07.120

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  • Combustion characteristics and NOx emissions of biogas fuels with various CO2 contents in a micro co-generation spark-ignition engine

    Yungjin Kim, Nobuyuki Kawahara, Kazuya Tsuboi, Eiji Tomita

    APPLIED ENERGY   182   539 - 547   2016年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    Biogas is a renewable alternative fuel for internal combustion engines that has several advantages over conventional fuels, including lower costs and reduced levels of harmful emissions. In particular, it exhibits a neutral recirculation loop for carbon dioxide (CO2), which is one of the main causes of global warming. In this study, we investigated biogas fuels with various compositions using a micro co-generation engine system. The ratio of methane to CO2 and engine load were varied, and the intake air and fuel flow rates were controlled to change the equivalence ratio. The results show that for a given engine load, the ignition delay and combustion period increased with CO2 content, and the combustion speed decreased. The fuel consumption increased slightly with CO2 content; however, the thermal efficiency improved using a lean burn strategy, resulting in lower nitrogen oxide (NOx) emission, and moreover, the use of biogas with the stoichiometric air-fuel ratio appears effective in reducing NOx emissions and can improve the fuel economy at higher loads. (C) 2016 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.apenergy.2016.08.152

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  • Quantum cascade laser assisted time-resolved measurements of carbon dioxide absorption during combustion in DME-HCCI engine

    Ulugbek Azimov, Nobuyuki Kawahara, Eiji Tomita

    FUEL   182   807 - 815   2016年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    We conducted experiments to investigate in-cylinder light absorption by carbon dioxide (CO2) during homogeneous charge compression ignition (HCCI) engine combustion. The combustion was fuelled with dimethyl ether. An in situ laser infrared absorption method was developed. We used an optical fibre spark plug sensor and the light source was a 4.301 mu m quantum cascade laser (QCL). We applied Lambert Beer's law in the case of a single absorption line of CO2. We were able to measure the transient CO2 formation during the HCCI combustion inside the engine cylinder. Our experiments showed that the laser light transmissivity level decreased with the intensity of the infrared (IR) signal. We compared the change in the transmissivity to the spatially integrated HCCI flame luminosity level and observed significant correlations between the flame luminosity level, heat release rate and transmissivity. Time-resolved experiments showed that the CO2 absorbance increases when the second peak of the rate of heat release (ROHR) is maximised. After combustion, the CO2 concentration was approximately 4 vol%, which agrees with the amount of CO2 formed during complete combustion. (C) 2016 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.fuel.2016.06.040

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  • Local fuel concentration measurement through spark-induced breakdown spectroscopy in a direct-injection hydrogen spark-ignition engine

    Kazi Mostafijur Rahman, Nobuyuki Kawahara, Daichi Matsunaga, Eiji Tomita, Yasuo Takagi, Yuji Mihara

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   41 ( 32 )   14283 - 14292   2016年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Quantitative measurements of local fuel concentrations were conducted in a direct injection hydrogen spark-ignition research engine using the spark-induced breakdown spectroscopy (SIBS) technique. For SIBS measurements, a new sensor was developed from a commercially available M12-type spark plug with no major modifications to the electrodes. The new plug sensor showed better durability and required less maintenance when used in a hydrogen research engine. Emission spectra from the plasma generated by the spark plug were collected through an optical fibre housed in the centre electrode of the plug and resolved spectrally for atomic emissions of Ha, 0(I), and N(I). The main focus of the present work was to characterise the effects of ambient pressure at ignition timing on spectral line emissions and to improve the accuracy of SIBS measurements by taking into account the pressure dependency of atomic emissions. A significant effect of the corresponding pressure at ignition timing was observed on spark-induced breakdown spectroscopic measurements and emission line characteristics. Retarded spark timing (i.e. higher ambient pressure at the ignition site) resulted in lower spectral line intensities as well as weaker background emissions. It is well established that with relatively higher pressure and density of atoms or molecules, the cooling of expanding plasma accelerates, and the collision probability increases, leading to both a weaker broadband continuum and atomic emissions. A "calibration MAP" representing the correlation of air excess ratio (relative air/fuel ratio) with both intensity ratio and pressure at ignition timing was created and subsequently used for quantitative measurements of local fuel concentrations for both port injection and direct injection strategies to demonstrate and explore the effects of pressure dependency of atomic emission on the accuracy of the SIBS measurements. Local stratification of the fuel mixture in the vicinity of the spark gap location associated with direct injection strategies was confirmed; the coefficient of variation of the local air excess ratio was relatively small for measurements made using the calibration map. This demonstrated that the measurement accuracy of local fuel concentrations through a spark plug sensor can be improved significantly when the pressure dependency of atomic emissions is taken into account. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2016.05.280

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  • Densitometry and temperature measurement of combustion gas by X-ray Compton scattering

    Hiroshi Sakurai, Nobuyuki Kawahara, Masayoshi Itou, Eiji Tomita, Kosuke Suzuki, Yoshiharu Sakurai

    Journal of Synchrotron Radiation   23 ( 2 )   617 - 621   2016年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:International Union of Crystallography  

    Measurement of combustion gas by high-energy X-ray Compton scattering is reported. The intensity of Compton-scattered X-rays has shown a position dependence across the flame of the combustion gas, allowing us to estimate the temperature distribution of the combustion flame. The energy spectra of Compton-scattered X-rays have revealed a significant difference across the combustion reaction zone, which enables us to detect the combustion reaction. These results demonstrate that high-energy X-ray Compton scattering can be employed as an in situ technique to probe inside a combustion reaction.

    DOI: 10.1107/S1600577516001740

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  • Densitometry and temperature measurement of combustion gas by X-ray Compton scattering 査読

    Hiroshi Sakurai, Nobuyuki Kawahara, Masayoshi Itou, Eiji Tomita, Kosuke Suzuki, Yoshiharu Sakurai

    JOURNAL OF SYNCHROTRON RADIATION   23   617 - 621   2016年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:INT UNION CRYSTALLOGRAPHY  

    Measurement of combustion gas by high-energy X-ray Compton scattering is reported. The intensity of Compton-scattered X-rays has shown a position dependence across the flame of the combustion gas, allowing us to estimate the temperature distribution of the combustion flame. The energy spectra of Compton-scattered X-rays have revealed a significant difference across the combustion reaction zone, which enables us to detect the combustion reaction. These results demonstrate that high-energy X-ray Compton scattering can be employed as an in situ technique to probe inside a combustion reaction.

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  • Combustion characteristics of wet ethanol ignited using a focused Q-switched Nd:YAG nanosecond laser

    Kazi Mostafijur Rahman, Nobuyuki Kawahara, Kazuya Tsuboi, Eiji Tomita

    FUEL   165   331 - 340   2016年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    Ethanol is a particularly promising bio-fuel, which is already widely used in the transportation sector. Much research has focused on laser ignition in internal combustion engines, because it offers a number of significant advantages. The motivation of this study is to reduce the higher cost of anhydrous ethanol by enabling the direct use of wet ethanol for combustion applications. This study reports the effects of water content on the laser ignition characteristics of air-ethanol flames with 0-40% water by volume added to the ethanol. Laser-induced breakdown was generated by focusing a 532-nm nanosecond pulse from a Q-switched Nd:YAG laser. High-speed visualisation of the combustion was achieved, together with analyses of the in-chamber pressure history, mass fraction burned, and ignition delay over a range of equivalence ratios. Removing the final 20% of water from ethanol is particularly energy intensive. The results of this investigation revealed that the flame growth rate and flame propagation velocity are both increased by adding up to 20% water (by volume) to ethanol, indicating a positive effect of the water at relatively low concentrations. It was also found that the ignition delay was shorter as the water content was increased up to a volume fraction of 20%. Therefore, it can be hypothesised that the presence of water enhances the ionisation process and increases the rate of radical generation during laser-induced breakdown of wet ethanol. Numerical analysis using the commercial software package CHEMKIN-PRO revealed a reduction in adiabatic flame temperature and laminar burning velocity due to the addition of water to ethanol. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.fuel.2015.10.067

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  • Effect of ambient pressure on local concentration measurement of transient hydrogen jet in a constant-volume vessel using spark-induced breakdown spectroscopy

    Md Tasyrif Abdul Rahman, Nobuyuki Kawahara, Kazuya Tsuboi, Eiji Tomita

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   40 ( 13 )   4717 - 4725   2015年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    We report an investigation of the effects of the ambient pressure on fuel concentration measurements of an injected jet of hydrogen using spark-induced breakdown spectroscopy (SIBS) in a constant-volume vessel. Measurements were carried out using hydrogen injected into a nitrogen environment with different ambient pressures, and the local concentrations were measured at various spark locations. The optical emission from the spark discharge at 501 nm (corresponding to nitrogen) and 656 nm (corresponding to hydrogen) was observed using SIBS. Spectrally resolved emission from the plasma was detected simultaneously using a spectrometer. The potential to determine the hydrogen/nitrogen ratio in the spark gap using was demonstrated. Spectral calibration was carried out using a hydrogen/nitrogen mixture, and hydrogen was injected at a pressure of 5.0 MPa into nitrogen with ambient pressures in the range 0.5-1.5 MPa. The results show an increase in the background radiation, as well as of the peaks corresponding to hydrogen and nitrogen atomic emission lines, as the ambient pressure increased. An increase in the density of nitrogen inside the chamber influenced the structure of the hydrogen jet, slowing the spray and reducing penetration, which altered the equivalence ratio at the location of the spark. When the spark occurred during injection, the behavior of the hydrogen jet was quasi-steady state; when the spark timing followed the injection, however, an unsteady state was observed. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2015.01.121

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  • Visualization and concentration measurement of a direct-injection hydrogen jet in a constant-volume vessel using spark-induced breakdown spectroscopy

    Md Tasyrif Abdul Rahman, Nobuyuki Kawahara, Kazuya Tsuboi, Eiji Tomita

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   39 ( 31 )   17896 - 17905   2014年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    In this work, spark-induced breakdown spectroscopy (SIBS) was employed to investigate the mixing process of a hydrogen jet in a constant-volume vessel. The local fuel concentration of the hydrogen jet was measured at several locations, using a SIBS sensor. A high-speed camera was used to visualize spark discharge fluctuations, and hydrogen jet concentration measurements were conducted simultaneously. Spectrally resolved atomic emissions from the plasma generated by the spark plug were examined to determine the local equivalence ratio. Direct visualization of the spark discharge provided useful information about the influence of spark discharge characteristics related to the spark timing. Using the developed SIBS sensor, atomic emission spectra were obtained from hydrogen H-alpha at 656 nm and nitrogen N (I) at 501 nm. Comparison of the intensity peaks of atomic emissions from hydrogen and nitrogen allows the local hydrogen concentration in a measured volume to be determined, and hence also the local equivalence ratio. The measurement results demonstrate the local variation in the equivalence ratio throughout the jet and along its axis. From the results, the spatial structure of the hydrogen jet affects the hydrogen/nitrogen mixing and could be clarified with SIBS technique when the spark is discharged. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2014.08.146

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  • Laser-induced plasma generation and evolution in a transient spray

    Nobuyuki Kawahara, Kazuya Tsuboi, Eiji Tomita

    OPTICS EXPRESS   22 ( 1 )   A44 - A52   2014年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OPTICAL SOC AMER  

    The behaviors of laser-induced plasma and fuel spray were investigated by visualizing images with an ultra-high-speed camera. Timeseries images of laser-induced plasma in a transient spray were visualized using a high-speed color camera. The effects of a shockwave generated from the laser-induced plasma on the evaporated spray behavior were investigated. The interaction between a single droplet and the laser-induced plasma was investigated using a single droplet levitated by an ultrasonic levitator. Two main conclusions were drawn from these experiments: (1) the fuel droplets in the spray were dispersed by the shockwave generated from the laser-induced plasma; and (2) the plasma position may have shifted due to breakdown of the droplet surface and the lens effect of droplets. (C) 2013 Optical Society of America

    DOI: 10.1364/OE.22.000A44

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  • Combustion and Emission Characteristics of a Premixed Charge Compression Ignition Engine

    Robert Kiplimo, Eiji Tomata, Nobuyuki Kawahara, Sumito Yokobe

    Journal of Sustainable Research in Engineering   1 ( 1 )   8 - 16   2014年

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  • Jet-guided combustion characteristics and local fuel concentration measurements in a hydrogen direct-injection spark-ignition engine

    Mithun Kanti Roy, Nobuyuki Kawahara, Eiji Tomita, Takashi Fujitani

    PROCEEDINGS OF THE COMBUSTION INSTITUTE   34   2977 - 2984   2013年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    Spark-ignition (SI) hydrogen engines based on direct injection (DI) promise significant advantages in terms of thermal efficiency and power output, and present a means of overcoming problems related to knocking, backfiring, and preignition. A better understanding of the effects of hydrogen jets on the fuel concentration distribution and mixing process in a DISI engine should provide new and useful insights into combustion optimization. The objective of the present work was to gain a deeper comprehension of the characteristics of late-injection hydrogen combustion. An experimental combustion setup was applied to a fired, jet-guided DISI engine operated at 600 rpm in stratified mode. GDI injector with the jet directed toward the spark plug was used to develop the stratified combustion concept. A high-speed camera synchronized with the spark was focused on a 52 mm-diameter field of view through a window at the bottom of the piston crown. A series of single-shot images captured at different intervals was used to study the time evolution of the flame distribution. Variations in the fuel injection timing relative ignition timing were found to impact the development of the early flame, as well as the flame propagation. This research also employed spark-induced breakdown spectroscopy (SIBS) to measure the local fuel-air concentration in the spark gap at the time of ignition under stratified-charge conditions. (C) 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.proci.2012.06.103

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  • UV-visible light absorption by hydroxyl and formaldehyde and knocking combustion in a DME-HCCI engine

    Ulugbek Azimov, Nobuyuki Kawahara, Eiji Tomita

    FUEL   98   164 - 175   2012年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    Experiments were conducted in a compression-expansion test engine to investigate the combustion characteristics in a homogeneous charge compression ignition (HCCI) engine fuelled with dimethyl ether. Two types of analyses were performed. In the first, ultraviolet-visible (UV-Vis) light absorbance was investigated to identify the formation behaviour of HCHO and OH during HCCI combustion. In the second, knocking combustion was investigated by analysing the spatially integrated flame luminosity and in-cylinder pressure oscillations. The time-resolved HCHO and OH profiles at different equivalence ratios showed that HCHO absorbance increased in the low-temperature reaction (LTR) and thermal-preparation regions and gradually decreased as the combustion approached the high-temperature reaction (HTR) region. The in-cylinder temperature in the LTR region had little effect on the rate of the maximum pressure rise, and this did not change much at different equivalence ratios. The results demonstrated that there was a marked difference between the intensity of the flame emissions of non-knocking and knocking events. The time-resolved integrated absorbance spectra of HCHO with peaks at 328, 340, and 354 nm that occurred before the OH peaks appeared suggested that when a certain threshold ratio of (dP/d theta R-LT)/(dP/d theta(HTR)) was reached, the amount of HCHO decreased due to reactions in the thermal-preparation region while the tendency to knock increased. (C) 2012 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.fuel.2012.03.033

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  • Effects of spray impingement, injection parameters, and EGR on the combustion and emission characteristics of a PCCI diesel engine

    Robert Kiplimo, Eiji Tomita, Nobuyuki Kawahara, Sumito Yokobe

    APPLIED THERMAL ENGINEERING   37   165 - 175   2012年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The effects of spray impingement, injection parameters, and exhaust gas recirculation (EGR) on the combustion characteristics and exhaust emissions of a premixed charge compression ignition (PCCI) diesel engine were investigated using a single-cylinder test engine and an optically accessible engine. Tests were carried out under constant speed with variable injection pressures and EGR rates. Exhaust emissions and in-cylinder pressures were measured under all experimental conditions. Analyses were conducted based on diesel spray evolution and combustion process visualisation coupled with performance and exhaust emissions. Higher injection pressures led to lower smoke, hydrocarbons (HC), and nitrogen oxide (NOx) emissions but had roughly the same CO emissions compared with lower injection pressures. Higher EGR rates led to the simultaneous reduction in NOx and soot emissions due to lower combustion temperatures compared to conventional diesel combustion. However, HC and CO emissions increased due to fuel impingement, bulk quenching, and over-mixing, leading to an air fuel mixture that was too lean to burn. An optimum spray targeting spot was identified, leading to lower emissions of soot, CO, and HC but higher NOx emissions without EGR. The simultaneous reduction in NOx and soot was achieved using the optimum spray targeting spot by introducing EGR, which was accompanied by homogenous combustion and a low luminosity flame attributed to fuel impingement on the piston bowl wall. (C) 2011 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.applthermaleng.2011.11.011

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  • Premixed mixture ignition in the end-gas region (PREMIER) combustion in a natural gas dual-fuel engine: operating range and exhaust emissions

    U. Azimov, E. Tomita, N. Kawahara, Y. Harada

    INTERNATIONAL JOURNAL OF ENGINE RESEARCH   12 ( 5 )   484 - 497   2011年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SAGE PUBLICATIONS LTD  

    This paper is concerned with engine experiments and spectroscopic analysis of premixed mixture ignition in the end-gas region (PREMIER) combustion in a pilot fuel ignited, natural gas dual-fuel engine. The results reveal the characteristics and operating parameters that induce and affect this combustion mode. The PREMIER combustion is followed by natural gas flame propagation. Pilot-injected diesel fuel ignites the natural gas/air mixture, and the flame propagates before the natural gas/air mixture is autoignited in the end-gas region. This combustion cycle differs from a knocking cycle in terms of combustion and emission characteristics. The PREMIER combustion can be controlled by pilot fuel injection timing, the equivalence ratio, and the exhaust gas recirculation (EGR) rate, and can be used as an effective method for high load extension on a dual-fuel engine. An analysis of the relationship between the maximum in-cylinder pressure and its crank angle (CA) is used to compare combustion dynamics during conventional, PREMIER, and knocking combustion. In PREMIER combustion, the heat release gradually transforms from the slower first-stage flame rate to the faster second-stage rate. During PREMIER combustion, the maximum indicated mean effective pressure (IMEP) and thermal efficiency increase by about 25 per cent compared with those of conventional combustion, and low carbon monoxide (CO) and total hydrocarbon (HC) emissions can be achieved. However, nitrogen oxide (NO(x)) emissions increase. Spectroscopic analysis shows that the intensity of the OH* emissions in the end-gas region increases as the combustion mode transforms from conventional to PREMIER to knocking. In all three modes, emission fluctuations above 650 nm can be observed in the end-gas region. These emissions are attributed to the luminosity from soot particles formed during the concurrent diesel fuel combustion.

    DOI: 10.1177/1468087411409664

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  • Multidimensional CFD simulation of syngas combustion in a micro-pilot-ignited dual-fuel engine using a constructed chemical kinetics mechanism

    Ulugbek Azimov, Masahiro Okuno, Kazuya Tsuboi, Nobuyuki Kawahara, Eiji Tomita

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   36 ( 21 )   13793 - 13807   2011年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    A multidimensional computational fluid dynamics (CFD) simulation of a constructed syngas chemical kinetic mechanism was performed to evaluate the combustion of syngas in a supercharged dual-fuel engine for various syngas initial compositions under lean conditions. The modelled results were validated by comparing predictions against corresponding experimental data for a supercharged dual-fuel engine. The predicted and measured in-cylinder pressure, temperature, and rate of heat release (ROHR) data were in good agreement. The effect of the hydrogen peroxide chain-propagation reaction on the progress of combustion under supercharged conditions was examined for different types of syngas using various initial H-2 concentrations. The effect of the main syngas kinetic mechanism reactions on the combustion progress was analysed in terms of their contribution to the total heat of the reaction. The best results compared with experimental data were obtained in the range of equivalence ratios below about 0.8 for all types of syngas considered in this paper. As the equivalence ratio increased above 0.8, the results deviated from the experiment data. The spatial distribution of the in-cylinder temperature and OH center dot within this equivalence-ratio range showed the completeness of the combustion. The present CFD model captured the overall combustion process well and could be further developed into a useful tool for syngas-engine combustion simulations. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2011.07.140

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  • Effect of syngas composition on combustion and exhaust emission characteristics in a pilot-ignited dual-fuel engine operated in PREMIER combustion mode

    Ulugbek Azimov, Eiji Tomita, Nobuyuki Kawahara, Yuji Harada

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   36 ( 18 )   11985 - 11996   2011年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The objective of this study was to investigate the performance and emissions of a pilot-ignited, supercharged, dual-fuel engine powered by different types of syngas at various equivalence ratios. It was found that if certain operating conditions were maintained, conventional engine combustion could be transformed into combustion with two-stage heat release. This mode of combustion has been investigated in previous studies with natural gas, and has been given the name PREmixed Mixture Ignition in the End-gas Region (PREMIER) combustion. PREMIER combustion begins as premixed flame propagation, and then, because of mixture autoignition in the end-gas region, ahead of the propagating flame front, a transition occurs, with a rapid increase in the heat release rate. It was determined that the mass of fuel burned during the second stage affected the rate of maximum pressure rise. As the fuel mass fraction burned during the second stage increased, the rate of maximum pressure rise also increased, with a gradual decrease in the delay between the first increase in the heat release rate following pilot fuel injection and the point when the transition to the second stage occurred. The H(2) and CO(2) content of syngas affected the engine performance and emissions. Increased H2 content led to higher combustion temperatures and efficiency, lower CO and HC emissions, but higher NOx emissions. Increased CO2 content influenced performance and emissions only when it reached a certain level. In the most recent studies, the mean combustion temperature, indicated thermal efficiency, and NOx emissions decreased only when the CO2 content of the syngas increased to 34%. PREMIER combustion did not have a major effect on engine cycle-to-cycle variation. The coefficient of variation of the indicated mean effective pressure (COV(IMEP)) was less than 4% for all types of fuel at various equivalence ratios, indicating that the combustion was within the stability range for engine operation. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2011.04.192

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  • Comparison of performance and emissions of a supercharged dual-fuel engine fueled by hydrogen and hydrogen-containing gaseous fuels

    Murari Mohon Roy, Eiji Tomita, Nobuyuki Kawahara, Yuji Harada, Atsushi Sakane

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   36 ( 12 )   7339 - 7352   2011年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    This study investigated the engine performance and emissions of a supercharged engine fueled by hydrogen (H(2)), and three other hydrogen-containing gaseous fuels such as primary fuels, and diesel as pilot fuel in dual-fuel mode. The energy share of primary fuels was about 90% or more, and the rest of the energy was supplied by diesel fuel. The hydrogen-containing fuels tested in this study were 13.7% H(2)-content producer gas, 20% H(2)-content producer gas and 56.8% H(2)-content coke oven gas (COG). Experiments were carried out at a constant pilot injection pressure and pilot quantity for different fuel air equivalence ratios and at various injection timings. The experimental strategy was to optimize the pilot injection timing to maximize engine power at different fuel air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. Better thermal efficiency was obtained with the increase in H(2) content in the fuels, and neat H(2) as a primary fuel produced the highest thermal efficiency. The fuel air equivalence ratio was decreased with the increase in H(2) content in the fuels to avoid knocking. Thus, neat H(2)-operation produced less maximum power than other fuels, because of much leaner operations. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking combustion. The emissions of CO and HC with neat H(2)-operation were 98-99.9% and NOx about 85-90% less than other fuels. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2011.03.070

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  • Cycle-resolved Residual Gas Concentration Measurement inside a Heavy-duty Diesel Engine using Infrared Laser Absorption(共著)

    Kawahara, N, Tomita, E, Ohtsuki, A, Aoyagi, Y

    Proceedings of the Combustion Institute   33   2903 - 2910   2011年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Cycle-resolved residual gas fraction measurements were made inside a heavy-duty diesel engine using an infrared absorption method. An in situ laser infrared absorption method was developed using an optical fiber sensor and a 4.301-μm quantum cascade laser (QCL) as the light source. We discuss the feasibility of obtaining in situ CO2 concentration measurements inside the engine combustion chamber using the newly developed optical fiber sensor system. Lambert-Beer's law can be applied for the case of a single absorption line of CO2, and the dependence of the CO2 molar absorption coefficient on the ambient pressure and temperature of was determined using a constant volume vessel. This coefficient decreased with increasing pressure, indicating almost constant at pressures over 1.0 MPa. CO2 concentration measurements were made in a compression-expansion engine in order to calibrate the measurement system. The feasibility of the optical fiber sensor system was then investigated in a heavy-duty diesel engine. We were able to measure the CO2 concentration inside the combustion chamber under various engine load conditions and were able to determine the internal exhaust gas recirculation (EGR) ratio. This measurement technique proved to be valuable in obtaining the cycle-to-cycle CO2 concentration of the residual gas in a heavy-duty diesel engine. © 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.proci.2010.07.017

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  • Effects of Compression Ratio and Simulated EGR on Combustion Characteristics and Exhaust Emissions of a Diesel PCCI Engine 査読

    Robert Kiplimo, Eiji Tomita, Nobuyuki Kawahara, Sumito Yokobe

    JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY   6 ( 3 )   463 - 474   2011年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC MECHANICAL ENGINEERS  

    The effects of compression ratio and simulated exhaust-gas recirculation (EGR) on combustion characteristics and exhaust emissions of a diesel PCCI engine were investigated using a single-cylinder test engine. Tests were carried out under constant speed with various compression ratios and EGR rates. Exhaust emissions and in-cylinder pressure were measured for all experimental conditions. Analyses based on engine performance and exhaust emissions were conducted. An optimum compression ratio that provided better indicated thermal efficiency and IMEP while yielding lower emissions of smoke, HC, and CO, and reasonable NOx without EGR was identified. High rates of EGR led to the simultaneous reduction of NOx and soot emissions due to a lower combustion temperature compared with conventional diesel combustion, with a slight penalty in HC and CO.

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  • In situ fuel concentration measurement near a spark plug in a spray-guided direct-injection spark-ignition engine using infrared absorption method(共著)

    Nobuyuki Kawahara, Eiji Tomita, Takuya Kadowaki, Tetsuya Honda, Hideaki Katashiba

    Experiments in Fluids   49 ( 4 )   925 - 936   2010年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Vaporized fuel concentration in a spray-guided direct-injection spark-ignition (SG-DISI) engine was measured using an optical sensor installed in a spark plug. A laser infrared absorption method was applied to quantify the instantaneous gasoline concentration near the spark plug. This paper discusses the feasibility of obtaining in situ air-fuel ratio measurements with this sensor installed inside an SG-DISI engine cylinder. First, the effects of the spray plume from a multi-hole injector on the vaporized fuel concentration measurements near the spark-plug sensor were examined using a visible laser. We determined the best position for the sensor in the engine, which was critical due to the spray and vapor plume formation. Then, a 3.392-μm He-Ne laser that coincided with the absorption line of the hydrocarbons was used as a light source to examine the stratified mixture found during ultra-lean engine operation. A combustible mixture existed around the spark plug during the injection period when a preset air-fuel ratio of 45.0 was used with different fuel injection timings and net mean effect pressure conditions. The effects of the orientation of the spark plug on the measured results and ignitability of the SG-DISI engine were examined. Orienting the spark plug vertically to one of the spray plumes provided more accurate results and better engine reliability. The study demonstrated that it was possible to qualify the air-fuel ratio near the spark plug during the injection period using the developed spark-plug sensor in an SG-DISI engine. © 2010 Springer-Verlag.

    DOI: 10.1007/s00348-010-0884-2

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  • Direct microscopic image and measurement of the atomization process of a port fuel injector(共著)

    Mohamed Esmail, Nobuyuki Kawahara, Eiji Tomita, Mamoru Sumida

    Direct microscopic image and measurement of the atomization process of a port fuel injector   21 ( 7 )   2010年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The main objective of this study is to observe and investigate the phenomena of atomization, i.e. the fuel break-up process very close to the nozzle exit of a practical port fuel injector (PFI). In order to achieve this objective, direct microscopic images of the atomization process were obtained using an ultra-high-speed video camera that could record 102 frames at rates of up to 1 Mfps, coupled with a long-distance microscope and Barlow lens. The experiments were carried out using a PFI in a closed chamber at atmospheric pressure. Time-series images of the spray behaviour were obtained with a high temporal resolution using backlighting. The direct microscopic images of a liquid column break-up were compared with experimental results from laser-induced exciplex fluorescence (LIEF), and the wavelength obtained from the experimental results compared with that predicated from the Kelvin-Helmholtz break-up model. The droplet size diameters from a ligament break-up were compared with results predicated from Weber's analysis. Furthermore, experimental results of the mean droplet diameter from a direct microscopic image were compared with the results obtained from phase Doppler anemometry (PDA) experimental results. Three conclusions were obtained from this study. The atomization processes and detailed characterizations of the break-up of a liquid column were identified; the direct microscopic image results were in good agreement with the results obtained from LIEF, experimental results of the wavelength were in good agreement with those from the Kelvin-Helmholtz break-up model. The break-up process of liquid ligaments into droplets was investigated, and Weber's analysis of the predicated droplet diameter from ligament break-up was found to be applicable only at larger wavelengths. Finally, the direct microscopic image method and PDA method give qualitatively similar trends for droplet size distribution and quantitatively similar values of Sauter mean diameter. © 2010 IOP Publishing Ltd.

    DOI: 10.1088/0957-0233/21/7/075403

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  • An experimental investigation on engine performance and emissions of a supercharged H2-diesel dual-fuel engine(共著)

    Murari Mohon Roy, Eiji Tomita, Nobuyuki Kawahara, Yuji Harada, Atsushi Sakane

    International Journal of Hydrogen Energy   35 ( 2 )   844 - 853   2010年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    This study investigated the engine performance and emissions of a supercharged engine fueled by hydrogen and ignited by a pilot amount of diesel fuel in dual-fuel mode. The engine was tested for use as a cogeneration engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant pilot injection pressure and pilot quantity for different fuel-air equivalence ratios and at various injection timings without and with charge dilution. The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. The engine was tested first with hydrogen-operation condition up to the maximum possible fuel-air equivalence ratio of 0.3. A maximum IMEP of 908 kPa and a thermal efficiency of about 42% were obtained. Equivalence ratio could not be further increased due to knocking of the engine. The emission of CO was only about 5 ppm, and that of HC was about 15 ppm. However, the NOx emissions were high, 100-200 ppm or more. The charge dilution by N2 was then performed to obtain lower NOx emissions. The 100% reduction of NOx was achieved. Due to the dilution by N2 gas, higher amount of energy could be supplied from hydrogen without knocking, and about 13% higher IMEP was produced than without charge dilution. © 2009 Professor T. Nejat Veziroglu.

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  • Evaluation of the Flame Lift-off Length in Diesel Spray Combustion Based on Flame Extinction (共著)

    Ulugbek AZIMOV, Nobuyuki KAWAHARA, Eiji TOMITA, Kazuya TSUBOI

    Journal of Thermal Science and Technology   5 ( 2 )   238 - 251   2010年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The interaction of spray and combustion processes forms a complex system of physical phenomena undergoing in IC engines. Studying this interaction is important to determine strategies for simultaneously reducing soot and NOx emissions from diesel engines. Spray combustion interactions are evaluated by the flame lift-off length - the distance from the injector orifice to the location of hydroxyl luminescence closest to the injector in the flame jet. Various works have been dedicated to successful simulations of lifted flames of a diesel jet by use of various combustion modeling approaches. In this work, flame surface density and flamelet concepts were used to model the diesel lift-off length. Numerical studies have been performed with the ECFM3Z model and n-Heptane fuel to determine the flame lift-off length under quiescent conditions. The numerical results showed good agreement with experimental data, which were obtained from an optically accessible constant volume chamber and presented at the Engine Combustion Network (ECN) of Sandia National Laboratories. It was shown that at a certain distance downstream from the injector orifice, stoichiometric scalar dissipation rate matched the extinction scalar dissipation rate. This computed extinction scalar dissipation rate correlated well with the flame lift-off length. For the range of conditions investigated, adequate quantitative agreement was obtained with the experimental measurements of lift-off length under various ambient gas O2 concentrations and ambient gas densities. © 2010 by JSME.

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  • Characterization of the Spray of the DISI Multi-hole Injector by Means of Phase Doppler Anemometer(共著)

    Fatma AHMED, Nobuyuki KAWAHARA, Eiji TOMITA, Mamoru SUMIDA

    Journal of Thermal Science and Technology   35 ( 2 )   844 - 853   2010年

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  • Characterization of the Spray of the DISI Multi-hole Injector by Means of Phase Doppler Anemometer

    Fatma Ahmed, Nobuyuki Kawahara, Eiji Tomita, Mamoru Sumida

    JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY   5 ( 1 )   36 - 50   2010年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC MECHANICAL ENGINEERS  

    The spray from a multi-hole injector applied to direct injection spark ignition (DISI) engine was investigated. In order to understand the detailed structure of the transient spray near the nozzle a combined LDA/PDA system was used. PDA system was optimized in order to detect relative smaller droplets. Size-classified technique was used to get deep information about the spray characterizations near nozzle. The experiments were performed at 7 MPa of injection pressure. At early stage of spray the droplet velocity distribution in the centre of the spray showed high value. Smaller droplets under 15 mu m showing followability to air flow, while larger droplets over 20 mu m will have drag due to momentum decay. Droplets of 15<D <= 20 mu m in diameter is criteria for follow/penetration near the nozzle. Near the nozzle, the atomization predominantly occurs at the centre region of the spray.

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  • Performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas

    Murari Mohon Roy, Eiji Tomita, Nobuyuki Kawahara, Yuji Harada, Atsushi Sakane

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   34 ( 23 )   9628 - 9638   2009年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    This study investigated the engine performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas and ignited by a pilot amount of diesel fuel. The engine was tested for use as a cogeneration engine, so power output while maintaining a reasonable thermal efficiency was important Experiments were carried out at a constant pilot injection pressure and pilot quantity for different fuel-air equivalence ratios and at various injection timings without and with exhaust gas recirculation (EGR). The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. The engine was tested first without EGR condition up to the maximum possible fuel-air equivalence ratio of 0 65. A maximum indicated mean effective pressure (IMEP) of 1425 kPa and a thermal efficiency of 39% were obtained. However, the nitrogen oxides (NOx) emissions were high. A simulated EGR up to 50% was then performed to obtain lower NOx emissions. The maximum reduction of NOx was 60% or more maintaining the similar levels of IMEP and thermal efficiency. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking combustion. (C) 2009 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved.

    DOI: 10.1016/j.ijhydene.2009.09.016

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  • Fuel concentration measurement of premixed mixture using spark-induced breakdown spectroscopy

    N. Kawahara, E. Tomita, S. Takemoto, Y. Ikeda

    SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY   64 ( 10 )   1085 - 1092   2009年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    This study determined the local equivalence ratio of a CH(4)/air mixture in a laminar premixed flame using spark-induced breakdown spectroscopy (SIBS) with a fiber-coupled intensified charge coupled device (ICCD) spectrometer. Spectrally resolved emission spectra of plasma generated by a spark plug were investigated for their potential to measure local fuel concentrations in a premixed mixture. The influence of key parameters, such as the camera gate timing and spark energy, on the intensity of radical emission was illustrated. The intensity ratio of CN/NH had a greater sensitivity to the equivalence ratio than did that of CN/CH, and the local equivalence ratio could be obtained with high resolution by measuring the local intensity ratios of CN/NH. Moreover, a spark-plug sensor with an optical fiber was developed for application in spark-ignition engines. The atomic emission intensity during the breakdown and arc phases of spark discharge could be obtained using the fiber-optic spark-plug sensor. The H(alpha)/O intensity showed better linearity than the CN/NH intensity ratio in lean mixtures. The results presented here confirm the use of SIBS as a diagnostic tool for spark-ignition engines. (C) 2009 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.sab.2009.07.016

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  • Performance and emission comparison of a supercharged dual-fuel engine fueled by producer gases with varying hydrogen content

    Murari Mohon Roy, Eiji Tomita, Nobuyuki Kawahara, Yuji Harada, Atsushi Sakane

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   34 ( 18 )   7811 - 7822   2009年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    This study investigated the effect of hydrogen content in producer gas on the performance and exhaust emissions of a supercharged producer gas-diesel dual-fuel engine. Two types of producer gases were used in this study, one with low hydrogen content (H(2) = 13.7%) and the other with high hydrogen content (H(2) = 20%). The engine was tested for use as a co-generation engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant injection pressure and injection quantity for different fuel-air equivalence ratios and at various injection timings. The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking combustion. Better combustion, engine performance, and exhaust emissions (except NO.) were obtained with the high H(2)-content producer gas than with the low H(2)-content producer gas, especially under leaner conditions. Moreover, a broader window of fuel-air equivalence ratio was found with highest thermal efficiencies for the high H(2)-content producer gas. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ijhydene.2009.07.056

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  • Visualization of auto-ignition and pressure wave during knocking in a hydrogen spark-ignition engine

    Nobuyuki Kawahara, Eiji Tomita

    INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   34 ( 7 )   3156 - 3163   2009年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Visualizations of auto-ignition inside the end-gas region due to flame propagation and pressure waves that occur during knocking were carried out in a hydrogen spark-ignition engine using a high-speed camera. Our results demonstrated that auto-ignition in an endgas region that was compressed by the propagating flame front could be visualized using the high-speed color camera. A large amount of unburned mixture caused by the auto-ignited kernel explosion generated the strong pressure waves. Strong pressure wave oscillations induced by the initial auto-ignition could be visualized using a video camera with a speed of 250 kframes/s. The auto-ignition and pressure waves caused the thermal boundary layer to breakdown near the cylinder wall and piston head, therefore combustion of the lubricant oil grease was visible inside burned gas region. This auto-ignition and pressure waves may result in damage to the cylinder wall and piston head during engine knocking. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved

    DOI: 10.1016/j.ijhydene.2009.01.091

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  • Laser-induced radical generation and evolution to a self-sustaining flame

    J. L. Beduneau, N. Kawahara, T. Nakayama, E. Tomita, Y. Ikeda

    COMBUSTION AND FLAME   156 ( 3 )   642 - 656   2009年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    Images and emission spectra of sparks produced by laser-induced breakdown of methane and propane air mixtures were investigated with a high degree of spatial and temporal resolution. The laser-induced breakdown was generated by focusing a 532-nm nanosecond pulse from a Q-switched Nd:YAG laser. The data were collected using an intensified high-speed camera and a single/multi-fiber Cassegrain optics system coupled to an ICCD spectrometer. Emission spectra of OH*, CN*, CH*, and C-2* radicals were also collected using spectra boxes. The results provided information about the different stages of the laser-induced breakdown, with a specific focus on the transition from a flame kernel to a self-sustaining flame. The plasma shape and emission spectrum were very reproducible. The differences in the size of the flame kernel and the evolution of the radical emissions were analyzed for mixtures that fired or misfired. The impact of the level of radicals in the flame kernel was a critical parameter for the firing process, starting around 1 mu s after the laser-induced breakdown. The transition from plasma cooling to the classical chemical reactions in the combustion zone was analyzed.
    Even though the flame kernel size was directly linked to the spark energy, this was not a key parameter toward evolution to a self-sustaining flame. The Taylor blast wave theory was used to plot the location of the shock based on the evolution of the flame kernel size. The location was calculated using a laser-supported detonation model. A very good correlation was observed with the hot gas ignition process. Our results allowed us to obtain information about the process leading to firing or misfiring for similar environments, resulting in a better understanding of the laser breakdown phenomena and the means of utilizing this technique in an industrial context. (C) 2008 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.combustflame.2008.09.013

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  • High temporally resolved optical measurement for laser ignition process of laminar premixed mixtures

    Takashi Nakayama, Nobuyuki Kawahara, Eiji Tomita, Yuji Ikeda

    Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B   74   1633 - 1640   2008年7月

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    This paper describes laser ignition process in a laminar premixed mixture of propane and air. The plasma was generated by focusing a second harmonic and several-nanosecond pulse emitted from a Q-switched Nd : YAG laser. Minimum ignition energy (MIE) was measured in different equivalence ratio. The growth process in the plasma and the hot kernel (flame kernel) around the MIE were observed using high-speed schlieren photography and a multi-fiber coupled to an ICCD spectrometer. The kernel size, the kernel expansion velocity and the emission spectrum history form the plasma and the kernel were determined under the ignition case and misfire case. Further, temperature of the plasma and the kernel were determined from the CN molecular spectra by comparing experimental and simulated (LIFBASE) spectra. The main results of this study are as follows : (1) In laser ignition method, combustion reaction begins through the cooling process in which the ion recombines to the atom, furthermore the atom recombines to the molecular after breakdown. (2) By analyzing the CH emission intensity history, it was considered that combustion reaction occurs confirmed about 100 μs after laser pulse. (3) The temperature of the plasma and the kernel decrease with time and there were almost no difference between fire and misfire. (4) The minimum ignition energy is the smallest near the stoichiometric mixture.

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  • 層流予混合気におけるレーザ着火過程の高時間分解光学計測

    中山崇, 河原伸幸, 冨田栄二, 池田裕二

    日本機械学会論文集(B編)   74 ( 743 )   1633 - 1640   2008年

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  • Spatially, temporally, and spectrally resolved measurement of laser-induced plasma in air

    N. Kawahara, J. L. Beduneau, T. Nakayama, E. Tomita, Y. Ikeda

    APPLIED PHYSICS B-LASERS AND OPTICS   86 ( 4 )   605 - 614   2007年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Images and emission spectra of sparks produced by laser-induced breakdown in air were investigated with a high degree of spatial and temporal resolution. The laser-induced breakdown was generated by focusing a 532-nm nanosecond pulse from a Q-switched Nd:YAG laser. The data were collected using a framing intensified charged coupled device (CCD) camera and a multi-fiber Cassegrain optics system coupled to an intensified CCD spectrometer. The results provided information about the different stages of laser-induced breakdown. The plasma shape and emission spectrum were very reproducible. Different ionization levels in the plasma kernels, which were observed using the high spatial resolution of the multi-fiber Cassegrain optics system, occurred during the plasma formation and cooling and at different locations within the plasma. This was due mainly to the thickness of the plasma relative to the laser wavelength, which created different ionization levels and energy absorption rates throughout. These observations were correlated with the plasma visualizations obtained with the framing ICCD camera. The plasma emission analysis permitted us to study the temperature evolution along the plasma during the laser-induced breakdown process. The analysis demonstrated the validity of a laser-supported wave model during the first stages of laser-induced breakdown and illustrated the weak dependence of the plasma temperature on the input energy.

    DOI: 10.1007/s00340-006-2531-4

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  • Auto-ignited kernels during knocking combustion in a spark-ignition engine

    Nobuyuki Kawahara, Eiji Tomita, Yoshitomo Sakata

    PROCEEDINGS OF THE COMBUSTION INSTITUTE   31 ( 2 )   2999 - 3006   2007年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    In this study, auto-ignition of end-gas due to flame propagation and intensity oscillations caused by shockwaves that occur during knocking combustion were visualized in a compression-expansion engine using a high-speed video camera. Chemical luminescence emissions of the end-gas were detected to analyze the chemical reactions caused by the auto-ignition. Four main conclusions were drawn from this study. When the end-gas region was compressed due to the propagating flame front, auto-ignited kernels appeared near a negative curvature of the flame front. This negative curvature was related to low-temperature chemistry. The large amount of unburned mixture generated a strong pressure wave caused by the auto-ignited kernels explosion. Visualized images of a regular propagating flame front and auto-ignited kernels confirmed that the knocking intensity had a strong relationship with the mass fraction of the unburned mixture. Oscillations of OH* radicals were synchronized with the in-cylinder pressure oscillations, which were produced due to the resulting shockwave. Before auto-ignition of the end-gas occurred, weak OH* radicals and very weak HCHO* radicals appeared in the end-gas region due to low-temperature chemistry. The OH* radicals played an important role in the low-temperature kinetic reactions. This confirms low-temperature chemical reaction of auto-ignited kernel in the end gas region. OH* radicals are a good indicator of the transition from low-temperature chemistry to high-temperature auto-ignition. (c) 2006 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.proci.2006.07.210

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  • Cycle-resolved measurements of the fuel concentration near a spark plug in a rotary engine using an in situ laser absorption method

    Nobuyuki Kawahara, Eiji Tomita, Kenta Hayashi, Michihiko Tabata, Kouhei Iwai, Ryoji Kagawa

    PROCEEDINGS OF THE COMBUSTION INSTITUTE   31 ( 2 )   3033 - 3040   2007年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    Cycle-resolved measurements of the fuel concentration near a spark plug in a commercial rotary engine were performed. An in situ laser infrared (IR) absorption method was developed using a spark plug sensor and a 3.392-mu m He-Ne laser as the light source. This wavelength coincided with the absorption line of hydrocarbons. The newly developed IR spark plug sensor had a higher signal-to-noise ratio than its previous version due to the optimization of its quartz lens and two optical fibers. The new sensor provided quantitative cycle-resolved fuel concentration measurements around the spark plug with a high temporal resolution. At lean preset air/fuel (A/F) ratios, fuel was mixed with the surrounding air gradually by the rotor motion in the plug hole of the rotary engine. Strong mixture inhomogeneities were measured during the compression stroke; the magnitude of these inhomogeneities decreased throughout the compression stroke. Cycle-resolved measurements were made to investigate the effects of the fuel concentration near the spark plug on the combustion characteristics of the commercial rotary engine. There was a strong correlation between the fuel concentration measured with the spark plug sensor and the combustion characteristics during the initial combustion period, which occurred faster when conditions were slightly richer than stoichiometric near the spark plug. The indicated mean effective pressure (IMEP) was slightly related to the A/F ratio near the spark plug. It was possible to measure the cycle-resolved A/F ratio near the spark plug and investigate its cycle-to-cycle fluctuations to achieve stable operation using the newly developed spark plug sensor. (c) 2006 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.proci.2006.08.088

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  • 軽油着火過給天然ガスエンジンにおける燃焼および排気特性

    深谷信彦, 冨田栄二, 河原伸幸, 丸山慶士, 薦田哲男

    自動車技術会論文集   38 ( 2 )   125 - 130   2007年

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  • バイオマスを用いた熱分解ガス軽油着火過給エンジンにおける燃焼および排気特性,

    深谷信彦, 冨田栄二, 河原伸幸, 丸山慶士, 薦田哲男

    日本機械学会論文集(B編)   73 ( 730 )   1337 - 1344   2007年

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▼全件表示

書籍等出版物

  • Natural Gas Engines For Transportation and Power Generation

    河原 伸幸( 担当: 共著 ,  範囲: Advanced Combustion in Natural Gas-Fueled Engines)

    Springer  2018年1月 

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  • The Micro-World Observed by Ultra High-Speed Cameras

    河原 伸幸( 担当: 共著 ,  範囲: Visualization of Combustion Processes of Internal Combustion Engines)

    Springer  2018年1月 

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  • 1.4.3 燃焼過程の光計測技術,革新的燃焼技術による高効率内燃機関開発最前線

    エヌティーエス  2015年 

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  • Chapter 2: Combustion and Exhaust Emission Characteristics of Diesel Micro-Pilot Ignited Dual-Fuel Engine in "Diesel Engine – Combustion, Emissions and Condition Monitoring" edited by Saiful Bari

    InTech (Open Access)  2013年 

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  • Developments in Laser Techniques and Fluid Mechanics

    2001年 

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MISC

  • 3D CFD of auto-ignition at the end gas region in dual-fuel gas engine

    Nobuyuki Kawahara, Eiji Tomita

    12th Asia-Pacific Conference on Combustion, ASPACC 2019   2019年1月

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    © Asia-Pacific Conference on Combustion, ASPACC 2019.All right reserved. The purpose of this study is to simulate the process of autoignition at the end gas region in dual-fuel gas engine under PREMIER combustion conditions using elementary chemical reactions of diesel fuel and homogeneous natural gas-air mixture. Elementary reaction scheme of diesel fuel and natural gas in dual-fuel gas engine was developed to simulate the diesel fuel ignition and the auto-ignition inside end-gas during flame propagation of natural gas-air mixture. Simulation procedure of dual fuel gas engine with diesel fuel ignition and the auto-ignition inside end-gas compressed by the flame propagation was considered and checked in the simulated constant volume vessel. The auto-ignition inside end-gas region in dual-fuel gas engine can be occurred using proposed procedure of 3D CFD.

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  • Visualization of combustion processes of internal combustion engines

    Nobuyuki Kawahara

    The Micro-World Observed by Ultra High-Speed Cameras: We See What You Don't See   261 - 275   2017年8月

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    記述言語:英語   出版者・発行元:Springer International Publishing  

    Very fast visualization of fuel injection and spray impingement on the wall, the laser ignition process, and auto-ignition of the end-gas region due to flame propagation during the engine knock cycle was demonstrated using an ultra-high-speed camera for a detailed understanding of the combustion process inside an internal combustion (IC) engine. The combustion process of an IC engine is complex, involving several thermal fluid phenomena. The high-speed video camera was an essential tool for visualizing and recording these high-speed phenomena. When more magnified images are needed, the ultra-high-speed camera and a long-distance microscope with a Barlow lens were used. Here, high-speed visualization techniques were shown to understand the combustion process inside an IC engine.

    DOI: 10.1007/978-3-319-61491-5_12

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  • Multidimensional CFD simulation of diesel spray combustion using chemical kinetics

    Nobuyuki Kawahara, Norihiro Takeda, Eiji Tomita

    COMODIA 2017 - 9th International Conference on Modeling and Diagnostics for Advanved Engine Systems   2017年1月

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    Copyright © 2017 by the Japan Society of Mechanical Engineers. The purpose of this study is to simulate the process from spray injection to spray combustion in a rapid compression machine (RCM) more precisely. Spray behavior and spray combustion were simulated by Generalized Tank and Tube (GTT) code which is based on KIVA code. First, the model coefficients of modified wave break-up model for liquid droplet break-up were considered using experimental results of droplet diameter and velocity obtained using a laser 2-focus velocimeter (L2F). Calculation results of spray tip penetration under atmospheric conditions were good agreement with experimental from the visualization of isothermal spray under higher injection pressure conditions. Second, multidimensional CFD simulations of diesel spray combustion using the reduced chemical kinetics were carried out under RCM experimental conditions with 900 K of ambient temperature and 4.1 MPa of ambient pressure. The modelled results were validated by comparing predictions against corresponding experimental results in RCM. The predicted and measured in-cylinder pressure were in good agreement. Ignition process of diesel spray combustion of free spray in RCM were discussed with spray break-up phenomena, entrainment structure of higher injection pressure, and OH radical formation of diesel spray combustion.

    DOI: 10.1299/jmsesdm.2017.9.B103

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  • Chemical Kinetics and Computational Fluid-Dynamics Analysis of H2/CO/CO2/CH4 Syngas Combustion and NOx Formation in a Micro-Pilot-Ignited Supercharged Dual Fuel Engine

    Nearchos Stylianidis, Ulugbek Azimov, Nobuyuki Kawahara, Eiji Tomita

    SAE Technical Papers   2017-   394 - 404   2017年

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    記述言語:英語   出版者・発行元:SAE International  

    A chemical kinetics and computational fluid-dynamics (CFD) analysis was performed to evaluate the combustion of syngas derived from biomass and coke-oven solid feedstock in a micro-pilot ignited supercharged dual-fuel engine under lean conditions. For this analysis, a reduced syngas chemical kinetics mechanism was constructed and validated by comparing the ignition delay and laminar flame speed data with those obtained from experiments and other detail chemical kinetics mechanisms available in the literature. The reaction sensitivity analysis was conducted for ignition delay at elevated pressures in order to identify important chemical reactions that govern the combustion process. We have confirmed the statements of other authors that HO2+OH=H2O+O2, H2O2+M=OH+OH+M and H2O2+H=H2+HO2 reactions showed very high sensitivity during high-pressure ignition delay times and had considerable uncertainty. The chemical kinetics of NOx formation was analyzed for H2/CO/CO2/CH4 syngas mixtures by using counter flow burner and premixed laminar flame speed reactor. The new mechanism showed a very good agreement with experimental measurements and accurately reproduced the effect of pressure, temperature and equivalence ratio on NOx formation. In order to identify the species important for NOx formation, a sensitivity analysis was conducted for pressures 4 bar, 10 bar and 16 bar and preheat temperature 300 K. The results show that the NOx formation is driven mostly by hydrogen based species while other species, such as N2, CO2 and CH4, have also important effects on combustion. Finally, the new mechanism was used in a multidimensional CFD simulation to predict the combustion of syngas in a micro-pilot-ignited supercharged dual-fuel engine and results were compared with experiments. The mechanism showed the closest prediction of the in-cylinder pressure and the rate of heat release (ROHR).

    DOI: 10.4271/2017-24-0027

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  • 第27回内燃機関シンポジウム(点火)

    自動車技術会,Engine Review   7 ( 6 )   17 - 18   2017年

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  • 新しい計測診断技術Ⅲ(新しい流れ計測技術)

    自動車技術会,Engine Review   7 ( 1 )   14 - 15   2017年

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  • Evaluation of Nozzle Exit Model for Transient Spray in a Multi -Hole DISI Injector

    Nobuyuki Kawahara, Shuhei Takada, Eiji Tomita

    19th Annual Conference of ILASS-Asia   2017年

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  • Effect of Bio-Gas Contents on SI Combustion for a Co-Generation Engine

    Yungjin Kim, Nobuyuki Kawahara, Eiji Tomita, Hiroshi Oshibe, Koichi Nishikawa

    SAE Technical Papers   2015- ( September )   2015年9月

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    記述言語:英語   出版者・発行元:SAE International  

    Bio-gas as an internal combustion (I.C.) engine fuel has many advantages such as cheaper fuel cost, low emission levels and especially the neutral recirculation loop of carbon dioxide, which is one of the principal factors in global warming. In this study, positive potentialities of bio-gas were investigated using a micro co-generation engine. The mixing ratio of methane (CH4) and carbon dioxide (CO2) was changed to simulate various types of bio-gases. Intake air and fuel flow rates were controlled to change the equivalence ratio. The engine load condition could be changed with the electric output power used. Base on the result, the higher CO2 content rate slowed down the engine speed in the same load condition and the combustion speed generally decreased under the same load condition with maintaining the engine speed. However thermal efficiency increased with lean burn conditions and NOX emission decreased with higher CO2 mixing rates.

    DOI: 10.4271/2015-01-1946

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  • Effect of Hydrogen Concentration on Engine Performance, Exhaust Emissions and Operation Range of PREMIER Combustion in a Dual Fuel Gas Engine Using Methane-Hydrogen Mixtures

    Cagdas Aksu, Nobuyuki Kawahara, Kazuya Tsuboi, Shun Nanba, Eiji Tomita, Morio Kondo

    SAE Technical Papers   2015- ( September )   2015年9月

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    記述言語:英語   出版者・発行元:SAE International  

    A single cylinder, supercharged dual fuel gas engine with micro-pilot fuel injection is operated using methane only and methane-hydrogen mixtures. Methane only experiments were performed at various equivalence ratios and equivalence ratio of 0.56 is decided as the optimum operating condition based on engine performance, exhaust emissions and operation stability. Methane-hydrogen experiments were performed at equivalence ratio of 0.56 and 2.6 kJ/cycle energy supply rate. Results show that indicated mean effective pressure is maintained regardless of hydrogen content of the gaseous fuel while thermal efficiency is improved and presence of hydrogen reduces cyclic variations. Increasing the fraction of hydrogen in the fuel mixture replaces hydrocarbon fuels and reduces carbon monoxide and hydrocarbon emissions. Mixtures with higher hydrogen content undergo faster heat release from flame propagation, approach knocking limit faster and are less knock resistant. 40% methane - 60% hydrogen mixture is prone to premature autoignition and superknocking, and is the critical concentration limit for methane-hydrogen mixtures.

    DOI: 10.4271/2015-01-1792

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  • Experimental Study on Combustion Characteristics of Wet Ethanol Ignited by Laser-Induced Breakdown

    Kazi Mostafijur Rahman, Nobuyuki Kawahara, Kazuya Tsuboi, Eiji Tomita

    Proc. Of 3rd Laser Ignition Conference (Argonne, USA)   2015年1月

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    © OSA 2015. Laser ignition of wet ethanol was carried out at equivalence ratio of 0.8. Additions of water in ethanol up to 20% (v/v) accelerated the combustion rate with shorter laser ignition delay compared to dehydrated ethanol.

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  • Effects of Bio-gas Contents on SI Combustion for a Co-generation Engine

    SAE 2015 Powertrains, Fuels and Lubricants Meeting (Kyoto Japan)   JSAE No.20159094/SAE 2015-01-1946   2015年

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  • Visualization of fuel impingement on the piston top in a DISI engine

    Proc. of 13th International Conference on Liquid Atomization and Spray Systems (ICLASS ) (Tainan, Taiwan)   B1-1-041   2015年

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  • ガソリン火花点火エンジンにおける火花放電挙動

    日本燃焼学会誌   57 ( 180 )   106 - 111   2015年

  • Combustion Diagnostics Using Time-Series Analysis of Radical Emissions in a Practical Engine

    21st Small Engine Technology Conference (SETC) (Osaka, Japan)   2015-32-0748   2015年

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  • レーザー誘起ブレークダウン分光法のエンジン研究への適用

    河原伸幸, 冨田栄二

    レーザー研究   42 ( 12 )   897 - 902   2014年

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  • Time-series Spectra Measurements from Initial Flame Kernel in a Spark-Ignition Engine

    Nobuyuki Kawahara, Atsushi Inoue, Eiji Tomita

    17th International Symposium on Applications of Laser Techniques to Fluid Mechanics   1 - 7   2014年

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  • Laser Ignition Characteristics of Hydrous Ethanol

    Kazi Mostafijur Rahman, Nobuyuki Kawahara, Kazuya Tsuboi, Eiji Tomita

    The 2nd Laser Ignition Conference   1 - 4   2014年

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  • Mixing process of direct injection hydrogen jet in a constant volume vessel by using spark-induced breakdown spectroscopy

    Md Tasyrif Bin Abdul Rahman, Nobuyuki Kawahara, Eiji Tomita

    SAE Technical Papers   11   2013年

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    記述言語:英語  

    Hydrogen spark-ignition (SI) engines based on direct-injection (DI) have been investigated because of their potential for high thermal efficiency and solving the problems related to knocking, backfiring, and pre-ignition. Wide range flammability limits in hydrogen engine enable smooth engine operation for a very lean mixture with low NOX. However, a too lean mixture may increase ignition delay and causes severe cyclic variations. There is a possibility that the turbulence occurred during injection of fuel surround the spark plug in the combustion chamber is major contributor to this phenomenon. To overcome this problem, a better understanding of the spark discharge and spark ignition during transient hydrogen jet is necessary. Therefore, it is very important to study an effect of local equivalence ratio and behavior of spark discharge in SI engine. This paper describes a mixing process of hydrogen jet using spark-induced breakdown spectroscopy (SIBS) in a constant volume vessel. Spark discharge fluctuation images was visualized by high speed camera with the concentration measurement simultaneously. The SIBS sensor was developed from a commercial spark plug with an optical fiber embedded in the spark plug. This technique was used to detect the component of samples using the light emitted by spark-induced plasma. Spectrally resolved emission of plasma generated by the SIBS sensor was detected simultaneously by spectrometer. In this study, the strongest intensity peak of Hα(656nm) and N(501) was chosen to measure the local concentration. Comparing the intensity peaks of atomic emissions from hydrogen and nitrogen gives local hydrogen concentration in the measured volume. Copyright © 2013 SAE International and Copyright © 2013 KSAE.

    DOI: 10.4271/2013-01-2526

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  • In-cylinder observations of chemiluminescence in turbulent premixed flames using a spark plug sensor with an optical fiber

    Nobuyuki Kawahara, Atsushi Inoue, Eiji Tomita

    SAE Technical Papers   11   2013年

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    記述言語:英語  

    The purpose of this study was to characterize the air/fuel ratio (AFR) of turbulent premixed flames in a spark-ignition (SI) engine. We developed a spark plug sensor with an optical fiber to detect the chemiluminescence spectra, specifically the intensity of the spectral lines related to OH*, CH*, and C2* free radicals. The sensor was composed of a sapphire window and optical fiber and is applicable to automobile SI engines. Measurements of the chemiluminescence intensity from OH*, CH*, and C2* radicals were obtained in turbulent premixed flames with a propane-air mixture for different AFRs in a compression-expansion machine (CEM). The performance of the spark plug sensor was compared with a Cassegrain reflector using an intensified charge-coupled device. The results showed good agreement with measurements obtained using the Cassegrain reflector. The spark plug sensor was shown to be useful for measuring chemiluminescence of turbulent premixed flames in an SI engine. Additionally, the performance of the sensor was evaluated using a high-speed camera, and the chemiluminescence intensity was shown to be related to the time-resolved optical images. Copyright © 2013 SAE International and Copyright © 2013 KSAE.

    DOI: 10.4271/2013-01-2578

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  • Spectrum Analysis of Chemiluminescence of a Low Sooting PCCI Diesel Engine Operating with Moderately Early Injection Timing

    Robert Kiplimo, Eiji Tomita, Nobuyuki Kawahara, Sumito Yokobe, Mitsui Engineering, Shipbuilding, Co

    The 8th International Conference on Modeling and Diagnostics for Advanced Engine Systems (COMODIA2012)   410 - 415   2012年12月

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    The spectral analysis of chemiluminescence of a PCCI diesel engine operating with moderately early injection timing was carried out in a single cylinder test engine. Investigations were conducted through direct visualization of the combustion phenomena with spectroscopic measurement of the intermediate species using a spectrometer coupled to ICCD camera. In order to understand the chemical kinetics of auto-ignition and combustion mechanism in PCCI engine, the spectral analysis of chemiluminescence was carried out. The following intermediate species were identified; OH*, CH*, CO-O recombination and formaldehyde (CH2O) which marked the different combustion phases. Formaldehyde was detected in the low temperature oxidation (LTO) region and isolated clearly by high spectral resolution. The OH* radicals marked the regions with premixed fuel-air mixtures and high temperature oxidation (HTO) region. CH* radicals were noted to mark well the fuel-rich region within the piston cavity after fuel impingement on the Derby hat wall. Soot formation arising from the fuel impingement on the Derby hat wall was oxidized in the late combustion phase. High temperature indicated by high intensity of OH* radicals led to faster oxidation of the soot in the late combustion phase. Copyright © 2012 by the Japan Society of Mechanical Engineers.

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  • Effect of Spark Timing on Combustion Characteristics in a Direct-Injection Hydrogen Engine

    Nobuyuki Kawahara, Mithun Kanti Roy, Takashi Fujitani, Eiji Tomita

    The 8th KSME-JSME Thermal and Fluids Engineering Conference (Incheon, Korea)   FR02-001   1 - 2   2012年

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  • Combustion and Emission Characteristics of a Low Emission and Highly Efficient PCCI Diesel Engine

    Robert Kiplimo, Eiji Tomita, Nobuyuki Kawahara, Sumito Yokobe, Mitsui Engineering, Shipbuilding, Co

    Sustainable Research and Innovation Conference 2012 at JKUAT   1 - 7   2012年

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  • 高速度カメラを用いた噴霧現象の可視化

    河原伸幸

    微粒化   2012年

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  • Simultaneous Measurement of Evaporating Droplet Diameter Using Phase Doppler Anemometry and High-speed Camera

    Nobuyuki Kawahara, Eiji Tomita, Hiroya Okano

    12th International Conference on Liquid Atomization and Spray Systems (ICLASS2012)   1 - 8   2012年

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  • Laser-Induced Plasma Generation and Evolution in a Transient Spray

    Nobuyuki Kawahara, Eiji Tomita, Shinya Nakamura

    16th Int. Symp. on Application of Laser Techniques on Fluid Mechanics   2012年

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  • Low Sooting Combustion in a PCCI Diesel Engine with Moderately Early Injection Timing

    Robert Kiplimo, Eiji Tomita, Nobuyuki Kawahara, Sumito Yokobe, Mitsui Engineering, Shipbuilding, Co

    The 8th KSME-JSME Thermal and Fluids Engineering Conference (Incheon, Korea)   FR02-001   1 - 4   2012年

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  • Effect of Equivalence Ratio on Combustion Characteristics in a Hydrogen Direct-Injection SI Engine

    Mithun Kanti Roy, Nobuyuki Kawahara, Eiji Tomita, Takashi Fujitani

    4th International Conference on Sustainable Automotive Technologies (ICSAT2012)   1 - 8   2012年

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  • High-Pressure Hydrogen Jet and Combustion Characteristics in a Direct-Injection Hydrogen Engine

    Roy, M, Kawahara, N, Tomita, E, Fujitani, T

    SAE International Journal of Fuels and Lubricants   5 ( 3 )   1414 - 1425   2012年

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  • DNS including the Chemical Process on a Solid Surface in Turbulent Premixed Flames

    Kazuya Tsuboi, Tatsuya Hasegawa, Nagoya Universit

    The 8th KSME-JSME Thermal and Fluids Engineering Conference (Incheon, Korea)   FR02-001   1 - 4   2012年

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  • Ignition, combustion and exhaust emission characteristics of micro-pilot ignited dual-fuel engine operated under PREMIER combustion mode

    Ulugbek Azimov, Eiji Tomita, Nobuyuki Kawahara

    SAE Technical Papers   2011年

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    記述言語:英語  

    The objective of this study is to investigate the performance and emissions in a pilot-ignited supercharged dual-fuel engine, fueled with different types of gaseous fuels under various equivalence ratios. It is found that if certain operating conditions are maintained, conventional dual-fuel engine combustion mode can be transformed to the combustion mode with the two-stage heat release. This mode of combustion was called the PREMIER (PREmixed Mixture Ignition in the End-gas Region) combustion. During PREMIER combustion, initially, the combustion progresses as the premixed flame propagation and then, due to the mixture autoignition in the end-gas region, ahead of the propagating flame front, the transition occurs with the rapid increase in the heat release rate. © Copyright 2011 Society of Automotive Engineers of Japan, Inc. and SAE International.

    DOI: 10.4271/2011-01-1764

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  • High-pressure hydrogen jet and combustion characteristics in a direct-injection hydrogen engine

    Mithun Kanti Roy, Nobuyuki Kawahara, Eiji Tomita, Takashi Fujitani

    SAE Technical Papers   2011年

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    記述言語:英語  

    Hydrogen spark-ignition (SI) engines based on direct-injection (DI) promise significant advantages in terms of thermal efficiency and power output, as well as a means of overcoming problems related to knocking, backfiring, and pre-ignition. In a DI hydrogen engine, the fuel/air mixture is formed by injecting a jet of hydrogen into the air inside the combustion chamber. An Ar-ion laser beam was used as a light source to visualize the hydrogen jet in a constant-volume chamber. This allowed us to study the structure of the jet in addition to other physical processes resulting from hydrogen gas injection. Combustion experiments were conducted in a single-cylinder SI optical research engine equipped with a DI system to detect the early kernel growth assisted by the spark, as well as flame propagation. Various equivalence ratios and fuel injection timings were analyzed to identify the effects on combustion. © Copyright 2011 Society of Automotive Engineers of Japan, Inc. and SAE International.

    DOI: 10.4271/2011-01-2003

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  • Effects of injection pressure, timing and EGR on combustion and emissions characteristics of diesel PCCI engine

    Robert Kiplimo, Eiji Tomita, Nobuyuki Kawahara, Shiyu Zhou, Sumito Yokobe

    SAE Technical Papers   2011年

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    記述言語:英語  

    Effects of injection parameters on combustion and emission characteristics of diesel PCCI engine operating on optical and test engine was investigated. PCCI combustion was achieved through slightly narrow included angle injector, low compression ratio coupled with exhaust gas recirculation. Analysis based on diesel spray evolution, combustion process visualization and analysis was carried out. Spray penetration was evaluated and related to the exhaust emissions. Advancing the injection timing and EGR extended the ignition delay, decreased NOx emissions and increased HC, smoke and CO emissions. Higher injection pressure led to low emissions of NOx, smoke, HC and comparable CO. Optimum spray targeting position for minimum emission was identified. Impingement on the piston surface led to deterioration of emissions and increased fuel consumption while spray targeting the upper edge of Derby hat wall showed improvement in emission and engine performance. © Copyright 2011 Society of Automotive Engineers of Japan, Inc. and SAE International.

    DOI: 10.4271/2011-01-1769

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  • Visualization of Auto-Ignition of End Gas Region without Knock in a Spark-Ignition Natural Gas Engine(共著)

    Eiji Tomita, Nobuyuki Kawahara, Jianjun Zheng

    Journal of KONES Powertrain and Transport   17 ( 4 )   521 - 527   2010年

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  • 点火プラグ組込型センサによる燃料濃度計測(共著)

    河原伸幸, 冨田栄二

    日本燃焼学会誌   52 ( 159 )   17 - 25   2010年

  • 点火プラグ実装型燃料・残留ガス濃度計測システム(共著)

    河原伸幸, 冨田栄二

    自動車技術   64 ( 2 )   56 - 61   2010年

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  • Effect of component of biomass-based gaseous fuels on combustion in a super-charged gas engine with micro-pilot injection(共著)

    Eiji Tomita, Nobuyuki Kawahara, Murari Mohon Roy

    Proceedings of Thirty-Second Task Leaders Meeting   138 - 144   2010年

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  • Fuel Concentration Measurement of Premixed Mixture in a Spark-Ignition Engine Using Spark-Induced Breakdown Spectroscopy(共著)

    Kawahara, N, Tomita, E, Oka, T, Ikeda, Y

    15th Int. Symp. on Application of Laser Techniques on Fluid Mechanics   2.11.3   2010年

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  • Residual Gas Concentration Measurement inside a Spark-ignition Engine Using Infrared Laser Absorption Method(共著)

    Kawahara, N, Tomita, E, Ohtsuki, A

    15th Int. Symp. on Application of Laser Techniques on Fluid Mechanics   2.8.3   2010年

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  • Knock Characteristics and Combustion Spectroscopy in a Small Natural Gas Engine Ignited with a Pilot Injection of Gas Oil(共著)

    Eiji Tomita, Nobuyuki Kawahara, Atsushi Sakane

    Second International Conference of Energy Engineering (ICEE-2)   31   2010年

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  • Visualization of Knocking Combustion in a Hydrogen Spark-Ignition Engine(共著)

    Mithun Kanti Roy, Nobuyuki Kawahara, Eiji Tomita

    18th World Hydrogen Energy Conference 2010 - WHEC2010   78 ( 6 )   141 - 148   2010年

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  • 赤外吸収法によるエンジンシリンダ内ガス濃度計測

    河原伸幸, 冨田栄二

    日本機械学会2009年度年次大会講演資料集   2009年

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  • 実用ガソリンインジェクタにおける微粒化過程の可視化(液糸分裂,液滴の衝突・合体挙動)

    河原伸幸, 冨田栄二, 中越真一, 住田守

    微粒化,Vol.18, No.62, pp.61-67.   2009年

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  • PDA analysis near nozzle region of Transient Spray from Multi-hole Injector of DISI engine

    Fatma Ahmed, Nobuyuki Kawahara, Eiji Tomita, Mamoru Sumida

    The 13th Annual Conference on Liquid Atomization and Spray Systems- Asia, pp.48-55.   2009年

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  • Microscopic Visualization of Transient Spray from Multi-hole Injector of DISI Engine

    M. Esmail, N. Kawahara, E. Tomita, M.Sumida

    ICLASS2009,Paper Number: 063   2009年

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  • Mixture formation process in a spark-ignition engine with ethanol blended gasoline

    Nobuyuki Kawahara, Eiji Tomita, Takuya Kadowaki

    SAE Technical Papers   2009年

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    記述言語:英語  

    In this study, fuel concentration measurements in a spark-ignition (SI) engine with ethanol blended gasoline were carried out using an optical sensor installed in the spark plug with laser infrared absorption technique. The spark plug sensor for in-situ fuel concentration measurement was applied to a port injected SI engine. The molar absorption coefficients of ethanol blended gasoline were determined for various pressures and temperatures in advance using a constant volume vessel with electric heating system. Ethanol blended gasoline with high volumetric ratios shows lower molar absorption coefficients due to lower molar absorption coefficients of ethanol. The molar absorption coefficients of ethanol blended gasoline can be estimated by considering the molar fraction of each component. Mixture formation processes of ethanol blended gasoline were investigated using spark-plug sensor installed in a spark plug in a port-injected SI engine with changing the fuel injection timing in an intake port. Delaying injection of ethanol blended gasoline caused a leaner fuel concentration around the spark plug and cycle-to-cycle fluctuation of combustion. Copyright © 2009 SAE International.

    DOI: 10.4271/2009-01-1957

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  • Effect of fuel injection parameters on engine performance and emissions of a supercharged producer gas-diesel dual fuel engine

    Murari Mohon Roy, Eiji Tomita, Nobuyuki Kawahara, Yuji Harada, Atsushi Sakane

    SAE Technical Papers   2009年

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    記述言語:英語  

    This study investigated the effect of some pilot fuel injection parameters, like injection timing, injection pressure and injection quantity on engine performance and exhaust emissions of a supercharged producer gas-diesel dual fuel engine. The engine has been tested to be used as a co-generation engine and its power output is an important matter. Experiments have been done to optimize the injection timing, injection pressure and injection quantity for the maximization of engine power. At constant injection pressures, there is an optimum amount of pilot injection quantity for that maximum engine power is developed without knocking and within the limit of maximum cylinder pressure. Above or below of that amount engine power is decreased. Higher injection pressures generally show better results than lower ones. However, good results can also be obtained with lower injection pressure, if maximum power timings can be selected. Two-stage combustion is obtained as a mentionable fact which is an indicator of maximum power output conditions as well as a precursor of knocking combustion. Smoke is found almost zero throughout the experiments and hydrocarbons (HC) are very low. However, carbon monoxide (CO) level at all experimental conditions is very high. Nitrogen oxides (NOx) at maximum power conditions are also very high. These need to be reduced. Copyright © 2009 SAE International.

    DOI: 10.4271/2009-01-1848

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  • Effect of EGR on combustion and exhaust emissions in supercharged dual-fuel natural gas engine ignited with diesel fuel

    Eiji Tomita, Yuji Harada, Nobuyuki Kawahara, Atsushi Sakane

    SAE Technical Papers   2009年

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    記述言語:英語  

    The combustion and exhaust emissions characteristics of a supercharged dual-fuel natural gas engine with a single cylinder were analyzed. We focused on EGR (Exhaust Gas Recirculation) to achieve higher thermal efficiency and lower exhaust emissions. The combustion of diesel fuel (gas oil) as ignition sources was visualized using a high-speed video camera from the bottom of a quartz piston. The luminous intensity and flame decreased as the EGR rate increased. Furthermore, the ignition delay became longer due to the EGR. Characteristics of the combustion and exhaust emissions were investigated with changing EGR rates under supercharged conditions. The indicated mean effective pressure and thermal efficiency decreased with increasing EGR rate. In addition, NOx emissions decreased due to the EGR. In this study two-stage combustion was observed. When two-stage combustion occurred, it was supposed that auto-ignition of compressed natural gas and air mixture occurred during the flame development. However, knocking did not occur. Two-stage combustion occurred under the condition of low EGR rate and advanced injection timing. The indicated mean effective pressure and thermal efficiency increased, during two-stage combustion
    however, NOx emissions also increased by a large amount compared to normal combustion. High indicated mean effective pressure, high thermal efficiency, and low NOx emissions were achieved just before the occurrence of two-stage combustion by changing EGR rate and injection timing of diesel fuel. Copyright © 2009 SAE International.

    DOI: 10.4271/2009-01-1832

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  • Visualization of autoignited kernel and propagation of pressure wave during knocking combustion in a hydrogen Spark-Ignition engine

    Nobuyuki Kawahara, Eiji Tomita, Mithun Kanti Roy

    SAE Technical Papers   2009年

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    記述言語:英語  

    Investigation of knocking combustion in a hydrogen spark-ignition engine is one of the major challenges for future vehicle development. The knock phenomenon in a Spark-Ignition (SI) engine is caused by autoignition of the unburned gas ahead of the flame. The explosive combustion of the end-gas creates a pressure wave that leads to damage of the cylinder wall and the piston head of the engine. We observed autoignition in the end-gas region due to compression by the propagating flame front using a high-speed colour video camera through the optically accessible cylindrical quartz window on the top of the cylinder head. Moreover, a high-speed monochrome video camera operating at a speed of 250, 000 frame/s was used to measure the pressure wave propagation. The goal of this research was to improve our ability to describe the effect of the autoignition process on the end-gas and propagating pressure wave during knocking combustion with the help of a high-speed video camera. Copyright ©2009 SAE International.

    DOI: 10.4271/2009-01-1773

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  • Effect of Nozzle Geometry on Atomization of Transient Spray from Port Fuel Injector

    Fatma Ahmed, Kawahara, N, Tomita, E, Sumida, M

    COMODIA2008, Paper No. SC3-2, in CD-ROM   429 - 436   2008年12月

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    The present paper reports an experimental investigation of the effect of nozzle geometry of port fuel injector PFI on exit flow velocity, the stability of primary spray behavior and spray droplet size. Several types of PFI with were tested. The investigation of exit flow velocity and stability (wavelength) of spray structure was performed using an ultra high-speed video camera (max. camera speed 1Mfps) with a long-distance microscope (whole image). The visualized experiments were carried out in a closed chamber at the atmospheric pressure. With back-lighting, the time-series images of the spray behavior were obtained. Using ultra high-speed camera with long-distance microscope and Barlow lens, droplet diameter could be visualized with high temporal resolution (magnified image). Experimental results of average exit velocity compared with NOZZLE FLOW model where experimental results of stability and droplet diameter compared with KH-RT breakup model. Experimental investigation showed that exit velocity, droplet diameter and stability (wavelength) influence by nozzle geometry. Copyright © 2008 by the Japan Society of Mechanical Engineers.

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  • Spray Behavior near the Nozzle of a DISI Multi-Hole Injector Using Phase Doppler Anemometer

    Mohamed Esmail, Kawahara, N, Tomita, E, Sumida, M

    COMODIA2008, Paper No. SC4-1, in CD-ROM   445 - 452   2008年12月

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    The spray from a multi-hole injector applied to direct injection spark ignition (DISI) engine was investigated. The spray has been injected into a constant volume chamber and has been visualized with a high speed video camera with a long distance microscope and quantified in terms of droplet velocity and diameter with HiDense PDA system. HiDense PDA system permits accurate measurements in spray with extremely high particle concentrations, and it is the only PDA system available that provide high quality measurements in the core region of the spray cone. The spray close to the nozzle has been investigated. Also the spray at the center axis far from the nozzle has been investigated at different injection pressure. PDA data have been processed by using a time-dividing method which divides the spray information into four distinct periods (F, C, R and T). As a result it was found that large particles ∼ (85 μm) which are injected at high speed ∼ (90 m/s) in the earliest stage lose their velocity rapidly due to breakup into smaller droplets and are overtaken by smaller but slower particles which are emitted during a later stage. The results also show that within the measured range the effect of injection pressure on droplet size was rather small. Copyright © 2008 by the Japan Society of Mechanical Engineers.

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  • Fuel spray and its measurement techniques

    Nobuyuki Kawahara, Eiji Tomita

    Nihon Enerugi Gakkaishi/Journal of the Japan Institute of Energy   87   897 - 902   2008年11月

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    In this report, fuel spray, especially engine application, and measurement techniques for fuel injection characteristics, such as break-up of liquid column, spray angle, penetration length, followability of droplets, droplet dispersion, entrainment vortex structure and so on, are explained. Microscopic visualization of liquid column break-up process in a gasoline PFI injector and simultaneous measurements of droplet diameter and velocity using phase Doppler anemometer (PDA/PDPA) are introduced as examples of measurement techniques. Obtained knowledge of spray and atomization characteristics using these techniques are mentioned in the case of unsteady spray from a gasoline injector.

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  • Microscopic Visualization of Liquid Column Break-up Process in Gasoline PFI Injector

    Kawahara, N, Tomita, E, Sumida, M

    14th Int. Symp. on Application of Laser Techniques on Fluid Mechanics, Paper No. 11.2.2, in CD-rom   2008年

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  • Fuel Concentration Measurements of Premixed Mixture Using Spark-Induced Breakdown Spectroscopy

    Kawahara, N, Ikeda, Y, Tomita, E, Takemoto, S

    5th International Conference on Laser-Induced Breakdown Spectroscopy (LIBS2008)   22 - 26   2008年

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  • Effect of Gas Flow on Combustion and Exhaust Emissions in a Dual Fuel Natural Gas Engine

    Tomita, E, Kawahara, N, Ohuchi, S, Komoda, T, Sakane, A

    Journal of KONES Powertrain and Transport   15 ( 2 )   519 - 527   2008年

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  • Soot formation during knocking combustion in a spark-ignition engine

    Kawahara, N, Tomita, E, Masatsuki, H

    Int. Symp. on Combustion, Accepted Poster, Paper No. 1P79   2008年

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  • Knock in a Hydrogen Spark-Ignition Engine

    Kawahara, N, Tomita, E, Yoshitomi, M

    Int. Symp. on Combustion, Accepted Poster, Paper No. 1P74.   2008年

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  • Temperature Measurement of Water with a Sensor by Laser Interferometry Technique

    Tomita, E, Kawahara, N

    14th Int. Symp. on Application of Laser Techniques on Fluid Mechanics, Paper No. 6.3.4, in CD-rom   2008年

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  • Visualization of Knocking Combustion in a Hydrogen Spark-Ignition Engine

    Kawahara, N, Tomita, E, Yoshitomi, M

    Meeting the Challenges to Sustainable Mobility   3 - 9   2008年

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  • Combustion and exhaust emissions characteristics in the supercharged engine ignited with gas oil fueled by pyrolysis gas generated from biomass

    Nobuhiko Fukatani, Eiji Tomita, Nobuyuki Kawahara, Keiji Maruyama, Tetsuo Komoda

    Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B   73   1337 - 1344   2007年6月

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    Pyrolysis gas produced from woody and waste biomass is considered as one of very important fuels to establish a sustainable society. In this study, a supercharged single cylinder gas engine with micro pilot ignition by gas oil was used. This ignition system has an advantage of large energy source, long period for ignition and stable ignition compared to the spark ignition system. Four types of artificial pyrolysis gases that were compressed into high pressure vessels were used. Compositions of these gases were H2, CO, CO 2, CH4 and N2. Combustion was visualized by using a high-speed color video camera from the bottom of the quartz piston. The pressure history was analyzed to obtain the rate of heat release in order to investigate combustion characteristics. Exhaust emissions of NOx, HC, CO and smoke were measured. Many ignition kernels produced by the iginition of gas oil initiate flame propagation of gas/air mixture and then flames move toward the wall of cylinder. Effects of injection timing, gas composition and equivalence ratio on engine performance were studied.

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  • Cycle-Resolved Measurements of the Fuel Concentration near a Spark Plug In an SI Engine Using an in-situ Laser Absorption Method

    Kawahara, N, Tomita, E, Hayashi, K

    6th Asia-Pacific Conference on Combustion   47 - 50   2007年1月

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    © 2007 Combustion Institute. All Rights Reserved. This paper describes the application of a spark plug sensor using a 3.392 μm infrared absorption technique to quantify the instantaneous gasoline concentration near the spark plug inside the engine cylinder. The mixture formation process near the spark plug in a port-injected spark-ignition (SI) engine was examined for different fuel injection timings, and determined that when the injection timing was delayed, a rich mixture remained near the top of the combustion chamber. Cyclic variations of fuel concentration at the spark timing were investigated.

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  • Fuel Break-up and Atomization Process near Nozzle Exit of Gasoline Injector

    Kawahara, N

    ILASS-Korea 2007, Invited Lecture.,   3 - 8   2007年

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  • Application of Laser Induced Breakdown Spectroscopy to Emission Gas Analysis of Spark Ignition Engine

    Ikeda, Y, Nishiyama, A, Kaneko, M, Kawahara, N, Tomita, E

    North American Symposium on Laser Induced Breakdown Spectroscopy   2007年

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  • Combustion in a Supercharged Biomass Gas Engine with Micro-pilot Ignition- Effect of Injection Pressure and Amount of Diesel Fuel -

    Tomita, E, Fukatani, N, Kawahara, N, Maruyama, K, Komoda, T

    Journal of KONES Powertrain and Transport   14 ( 2 )   513 - 520   2007年

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  • スワールインジェクタのノズル近傍における液膜分裂過程の可視化

    河原伸幸, 冨田栄二, 住田守

    微粒化   16 ( 54 )   24 - 33   2007年

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  • Gas temperature measurement in a DME-HCCI engine using heterodyne interferometry with spark-plug-in fiber-optic sensor

    Changhee Lee, Nobuyuki Kawahara, Eiji Tomita, Kenji Inoshita

    SAE Technical Papers   116 ( 4 )   316 - 324   2007年

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    記述言語:英語  

    Non-intrusive measurement of transient unburned gas temperatures was developed with a fiber-optic heterodyne interferometry system. Using the value of the Gladstone-Dale constant for DME gas and combustion pressure we can calculate the in-cylinder temperature inside unburned and burned region. In this experimental study, it was performed to set up a fiber-optic heterodyne interferometry technique to measure the temperature before and behind the combustion region in a DME-HCCI engine. At first, measured temperature was almost the same as the temperature history assuming that the process that changes of the unburned and the burned are polytropic. In addition, we measured the temperature after combustion which of condition was burned gas with DME-HCCI combustion. The developed heterodyne interferometry used the spark-plug-in fiber-optic sensor has a good feasibility to measure the unburned and burned temperature history. Copyright © 2007 Society of Automotive Engineers of Japan, Inc.

    DOI: 10.4271/2007-01-1848

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  • Residual gas fraction measurement inside engine cylinder using infrared absorption method with spark-plug sensor

    Nobuyuki Kawahara, Eiji Tomita, Yutaka Tanaka

    SAE Technical Papers   2007年

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    記述言語:英語  

    In this study, residual gas fraction measurements in a spark-ignition engine were carried out using an optical sensor installed in the spark plug with infrared absorption method. The residual gas fraction inside engine cylinder is proportional to the CO2 concentration. Infrared absorption method was applied and an infrared lamp and optical filter (center wavelength: around 4.3 μm) that coincides with the absorption lines of CO2 was used as a light source.The molar absorption coefficient of CO2 is discussed and compared to results in the HITRAN database. The effect of water vapor absorption doesn't affect the absorption of CO2. The absorption characteristics of CO2 were determined in advance using a constant volume vessel. Molar absorption coefficient depends on the CO2 concentration and ambient pressure and temperature, and wavelength of absorption line. Further experiments should be carried out for the quantitative measurements of CO2 concentration using infrared lamp and band-pass filter. The spark plug sensor for in-situ CO2 concentration measurement was applied to a compression-expansion machine and also to a port injected SI engine. It was possible to qualify the CO2 concentration inside residual gas during the compression stroke using the developed optical system with new spark plug sensor both in compression-expansion machine and commercial spark-ignition engine. Copyright © 2007 Society of Automotive Engineers of Japan, Inc.

    DOI: 10.4271/2007-01-1849

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  • In situ measurement of water temperature with a sensor using interferometry

    Eiji Tomita

    PROCEEDINGS OF THE ASME/JSME THERMAL ENGINEERING SUMMER HEAT TRANSFER CONFERENCE 2007, VOL 3   3   727 - 733   2007年

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    記述言語:英語   出版者・発行元:AMER SOC MECHANICAL ENGINEERS  

    It is very important to measure fluid temperature in research and industrial fields. However, there are no devices with high-response measurement. In this study, a sensor system is proposed to measure the temperature with very high response using interferometry. The sensor for temperature measurement utilizes the difference in measurement length between two laser beams. Both are the test beams, and there is no reference beam. The two beams pass mostly through closely arranged paths; therefore, the effect of mechanical vibration on the two test beams is expected to be very small. The laser beam was introduced through a selfoc micro lens (SML) into a polarization-maintaining fiber connected with a sensor part. The beam emitted from another SML was divided into two. Both beams enter a quartz block and are reflected at the corner to change direction by an angle of a quarter pai radian. They then pass through the test section although the lengths of the two beams are different in the measurement region. This sensor was installed on a side wall of a vessel. Water was poured into the vessel and stirred with a hot magnetic stirrer. The temperature near the sensor was also measured with a thermocouple as a reference. This paper focuses on the confirmation and evaluation of this system of temperature measurement. When the direction of the fringe shift with two photo-detectors was judged, the direction of the temperature could be distinguished. One feature of this sensor is that it minimizes the effect of the thermal boundary layer. If the condition of the fluid near the test section is uniform, both beams have almost the same boundary layers. Then, both thermal boundary layers are expected to be cancelled because the length of the test section is the difference between both beams. As a result, it was confirmed that this sensor system is useful for detecting changes in water temperature.

    DOI: 10.1115/HT2007-32022

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  • Combustion Characteristics and Performance of Supercharged Pyrolysis Gas Engine with Micro-Pilot Ignition,

    Tomita, E, Fukatani, N, Kawahara, N, Maruyama, K, Komoda, T

    CIMAC 2007, Paper No.178.   2007年

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  • レーザ誘起ブレイクダウン分光法によるエンジン排気ガス計測

    河原伸幸, 池田裕二, 冨田栄二

    東北大学金研ワークショップ   2007年

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  • 位相ドップラ法(PDA/PDPA)による噴霧粒径計測

    河原伸幸, 松本雅則

    第3回微粒化セミナー   45 - 58   2007年

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  • In-situ Residual Gas Concentration Measurement near a Spark Plug In a Motorcycle SI Engine

    Kawahara, N, Tomita, E, Yasuda, H

    Small Engine Technology Conference 2007, SAE Paper No. 2007-32-0049   2007年

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  • An aerosol nozzle that improves the spray agglomerative characteristics for optimal insecticide delivery to the target

    Yuji Ikeda, Seung Mo Kim, Yoshihiro Horibe, Shigeki Takaki, Nobuyuki Kawahara

    10th International Conference on Liquid Atomization and Spray Systems, ICLASS 2006   2006年12月

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    Spray characteristics were investigated to determine the optimum aerosol spray for insecticides while considering volatile organic carbon (VOC) reduction. Our ultimate goal is to improve the efficiency of killing insects while using less aerosol spray, which contains chemicals, oil, and dimethyl ether (DME). Most of the oil and propellant fail to reach the target, and fall to the ground. The propellant is used to break droplets into smaller droplets and to carry them to the target. Most of the propellant's energy is used for carrying these droplets, although the remaining droplets are very small compared to those produced at the nozzle. We investigated the droplet characteristics over the entire distance from the nozzle to the target. Here, we tested different nozzle dimensions and compared single- and double-hole nozzles. We measured the spray characteristics near the nozzle to evaluate the droplet-forming process by examining droplet separation, agglomeration, collision, and size to elucidate the spray behavior and determine the dominant factors involved in designing and developing a nozzle for spraying insecticides most effectively. The key factor for developing the optimum nozzle for spraying insecticides is not the number of holes or nozzle diameter, but the agglomeration process and the amount at the target distance. The key to developing a system that decreases VOC dramatically is how the droplets are generated at the nozzle. Droplet diameter and velocity when exiting the nozzle need to be understood quantitatively and controlled; the most important considerations are to maximize spray agglomeration, in order to deliver droplets with an effective diameter to the target, and to reduce the number of oversized droplets failing to reach the target.

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  • PDA measurement of transient spray formed by a DISI multi-hole injector

    Kawahara, N, Tomita, E, Nakasuji, H, Sumida, M

    ICLASS2006,   2006年12月

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    The droplet characteristics of unsteady fuel spray formed by multi-hole injector used in direct injection gasoline engine was investigated. In order to understand the detail structure of transient spray, a phase Doppler anemometer was used. The traverse system of the vessel was designed to obtain two-dimensional structure of spray. The laser power at measurement volume was optimized in order to detect relative smaller droplets. It is necessary to evaluate the effect of laser power of measurement volume on detection limit of smaller droplets under 10 μm. Phase locking method was used to analyze ensemble mean value of axial/radial droplet velocity, axial/radial slip velocity, relative droplet Reynolds number, and droplet turbulent kinetic energy. As a result, smaller droplets under 10 μm can follow the entrainment vortex at the spray shell. On the other hand, larger droplets over 30 μm have larger velocity to penetrate the entrainment vortex. Intermediate droplets of 15<D≦ 20μm in diameter are criteria for follow/penetration of vortex.

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  • Spatial and Temporal Characteristics of Laser-induced Air Plasma

    Kawahara, N. Tomita, E. Nakayama, T. Ikeda, Y. Nishiyama, A

    44th AIAA Aerospace Sciences Meeting and Exhibit,   23   17586 - 17595   2006年12月

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    We investigated laser-induced breakdown in air using a framing intensified charged coupled device (ICCD) camera and fiber-coupled ICCD spectrometer with Cassegrain optics. Localized breakdown plasma was generated from the laser pulse of a Q-switched Nd:YAG laser with a wavelength of 532 nm, and we obtained the temporal evolution of the air plasma shape, size, and location. During the initial stage, breakdown occurred on the laser side of the focal point due to the absorption of the pulse energy. Then, the breakdown plasma generally propagated in the direction of the laser. The propagation speed of the laserinduced breakdown was estimated to exceed 10 km/s during the initial stage of breakdown. The high spatial resolution of the Cassegrain optics system was used to observe different ionization levels in the breakdown plasma. Continuous background due to ionization appeared during the earliest stage of plasma development. The intensity of this background decreased after 100 ns and the atomic emission spectra of nitrogen (NI, 745 nm), oxygen (OI, 777 and 821 nm) and hydrogen (HI, 655.5 nm) appeared 200 ns after the laser pulse. The plasma temperature could be evaluated using the two-line ratio between the OI emission line intensities. We determined that simultaneous measurement using both the framing ICCD camera and an ICCD spectrometer with Cassegrain optics could be very useful for investigating the breakdown of laser-induced air plasma.

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  • Local equivalence ratio measurement of CH<inf>4</inf>/air and C <inf>3</inf>H<inf>8</inf>/air laminar flames by laser-induced breakdown spectroscopy

    Yuji Ikeda, Atsushi Nishiyama, Nobuyuki Kawahara, Eiji Tomita, Takashi Nakayama

    Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting   16   11586 - 11598   2006年12月

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    The local equivalence ratios of CH4/air and C3H 8/air mixtures were measured using a laser-induced breakdown spectroscopy technique with a fiber-coupled ICCD spectrometer with Cassegrain optics. Localized breakdown plasma was generated from the pulse of a Q-switched Nd:YAG laser with a wavelength of 532 nm. This system allowed us to measure laser-induced plasma spectra with high spatial and temporal resolution. The specified intensity ratio and set up equivalence ratios were well correlated and found to be a good indicator in practical measurement. The intensity ratio indicated a remarkable relationship regardless the presence of the flame. For the unburned and burned regions, there were some differences in the change in the intensity ratio, but the calibration slopes were almost similar. It was found that this technique can measure the local equivalence ratio of methane or propane premixed laminar flame regardless a flame. The intensity ratio was not a function of the incident beam intensity or flow rate, which is very acceptable for practical measurement. In this experiment, the relative error was around 5%.

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  • In-Situ Fuel Concentration Measurement Using an IR Spark Plug Sensor by Laser Infrared Absorption Method- Application to a Rotary Engine-

    Kawahara,N, Tomita,E, Hayashi, K, Tabata, M, Iwai, K, Kagawa, R

    13th Int. Symp. on Application of Laser Techniques on Fluid Mechanics,   2006年

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  • In-Situ Fuel Concentration Measurement near Spark Plug by 3.392 m Infrared Absorption Method —Pressure and Temperature Dependence of the Gasoline Molar Absorption Coefficient

    Kawahara, N, Tomita, E, Nishiyama, A, Hayashi, K

    SAE 2006 World Congress,   2006年

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    記述言語:英語  

    This paper describes the development and application of a spark plug sensor using a 3.392 μm infrared absorption technique to quantify the instantaneous gasoline concentration near the spark plug. We developed an in situ laser infrared absorption method using a spark plug sensor and a 3.392 μm He-Ne laser as the light source; this wavelength coincides with the absorption line of hydrocarbons. First, we established a database of the molar absorption coefficients of premium gasoline at different pressures and temperatures, and determined that the coefficient decreased with increasing pressure above atmospheric pressure. We then demonstrated a procedure for measuring the gasoline concentration accurately using the infrared absorption technique. The history of the molar absorption coefficient of premium gasoline during the experiment was obtained from the established database using measured in-cylinder pressures and temperatures estimated by taking the residual gas into consideration. These values provided instantaneous fuel concentrations in the engine cylinder. We examined the mixture formation process near the spark plug in a port-injected spark-ignition (SI) engine for different fuel injection timings, and determined that when the injection timing was delayed, a rich mixture remained near the top of the combustion chamber. Copyright © 2006 SAE International.

    DOI: 10.4271/2006-01-0182

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  • Local equivalence ratio measurement of CH4/Air and C3H8/Air laminar flames by Laser-Induced Breakdown Spectroscopy

    Ikeda, Y. Nishiyama, A. *Kawahara, N. Tomita, E. Nakayama, T

    44th AIAA Aerospace Sciences Meeting and Exhibit   2006年

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  • A New Sensor for Temperature Measurement of Water by Laser Interferometry Technique

    Tomita, E, Kawahara, N, Toda, Y

    13th Int. Symp. on Application of Laser Techniques on Fluid Mechanics,   2006年

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  • Combustion Characteristics and Performance of Supercharged Micro-pilot Natural Gas Engine

    Fukatani, N, Tomita, E, Kawahara, N, Maruyama, K, Komoda, T

    FISITA2006,   2006年

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  • Local Equivalence Ratio Measurement of CH4/air and C3H8/air Laminar Flames with and without flame front by LIBS

    Y. Ikeda, A. Nishiyama, N. Kawahara, T. Nakayama, E. Tomita

    LIBS2006, Oral presentation   2006年

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  • Highly Spatially Resolved Measurements of Laser-induced Plasma in Laminar Premixed Methane-Air Flow

    T. Nakayama, N. Kawahara, E. Tomita, Y. Ikeda, J.L. Beduneau

    LIBS2006,poster   2006年

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  • Development of an aerosol nozzle to optimally deliver insecticides to the target and improve the agglomerative characteristics of the spray

    Ikeda, Y, Kim, S.M, Horibe, Y, Takaki, S, Kawahara, N

    ICLASS2006,   2006年

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  • 火花点火機関におけるノッキング時の自着火部の可視化

    河原伸幸, 冨田栄二

    自動車技術会ガソリン機関部門シンポジウム,   No.17-06,pp.24-29.   2006年

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  • LIBS法を用いた層流予混合火炎における当量比計測

    池田裕二, 西山 淳, 河原伸幸, 冨田栄二

    日本分光学会レーザー誘起プラズマ分光部会・日本鉄鋼協会学会部門研究会”次世代鉄鋼迅速オンサイト分析の実用化”・合同講演会   2006年

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  • 層流予混合ガスにおけるレーザ誘起プラズマの高空間・高時間分解光学計測

    河原伸幸, 池田裕二, 中山崇, 冨田栄二

    日本分光学会レーザー誘起プラズマ分光部会・日本鉄鋼協会学会部門研究会”次世代鉄鋼迅速オンサイト分析の実用化”・合同講演会   2006年

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  • Anchor Point Structure Measurements for Laminar Propane/Air and Methane/Air Premixed Flame using the Local Chemiluminescence Spectra

    Y. Ikeda, A. Nishiyama, S.M. Kim, N. Kawahara, E. Tomita

    31st International Symposium on Combustion,   2006年

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  • Spatially and Temporally Resolved Optical Measurement of Laser Ignition for Laminar CH4/Air Mixtures

    Nakayama, T, Kawahara, N, Tomita, E, Ikeda, Y, Beduneau, J

    31st International Symposium on Combustion,   2006年

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  • Measurement of flame propagation characteristics in an SI engine using micro-local chemiluminescence technique

    Nobuyuki Kawahara, Eiji Tomita, Akira Takeuchi, Shigeyuki Arimoto, Yuji Ikeda, Atsushi Nishiyama

    SAE Technical Papers   2005年

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    記述言語:英語  

    A small Cassegrain optics sensor was developed to measure local chemiluminescence spectra and the local chemiluminescence intensities of OH*, CH*, and C2* in a four-stroke spark-ignition (SI) engine in order to investigate the propagation characteristics of the turbulent premixed flame. The small Cassegrain optics sensor was an M5 type that could be installed in place of a pressure transducer. The measurements could be used to estimate the flame propagation speed, burning zone thickness, and local air/fuel (A/F) ratio for each cycle. The specifications of the small Cassegrain optics sensor were the same as those used for previous engine measurements. In this paper, measurements were made of several A/F ratios using gasoline to fuel the model engine. The performances of two Cassegrain optics sensors were compared to demonstrate the advantages of the new small sensor by measuring the local chemiluminescence intensities of a turbulent premixed flame in the model engine. The measurements suggested that the small Cassegrain optics sensor is superior to the conventional Cassegrain sensor and can provide stable data for measurements over several hours, which should be sufficient for practical combustion diagnostics. This sensor proved useful for estimating the flame propagation characteristics. In addition, the sensor should be useful for local A/F ratio measurements in an engine cylinder. Copyright © 2005 SAE International.

    DOI: 10.4271/2005-01-0645

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  • 点火プラグ実装型燃料濃度計測センサ

    河原伸幸, 冨田栄二

    日本機械学会誌   Vol.108, No.1037, p311.   2005年

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  • Fuel Breakup near Nozzle Exit of Multi-Hole Injector for DISI Engine

    Kawahara, N. Tomita, E. Nakayama, T. Sumida, M

    18th Internal Combustion Engine Symposium (International)   2005年

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  • Local stoichiometry measurement of CH4/Air and C3H8/Air laminar flames by LIBS

    Ikeda, Y. Nishiyama, A. *Kawahara, N. Tomita, E. Kurahashi, T

    Pacifichem 2005   2005年

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  • Highly spatially resolved time evolution of laser-induced air plasma spectrum

    Kawahara, N. Tomita, E. Nakayama, T. Kurahashi, T. Ikeda, Y. Nishiyama, A

    Pacifichem 2005   2005年

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  • LDV/PDAの基礎と応用

    河原伸幸

    機械の研究   Vol.57, No.9, pp.937-944.   2005年

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  • 超音波浮揚における液滴近傍音響流のPIV計測

    河原伸幸, 冨田栄二

    微粒化   2005年

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  • In-spark-plug sensor for analyzing the initial flame and its structure in an SI engine

    Yuji Ikeda, Atsushi Nishiyama, Nobuyuki Kawahara, Eiji Tomita, Shigeyuki Arimoto, Akira Takeuchi

    SAE Technical Papers   2005年

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    記述言語:英語  

    An in-spark-plug flame sensor was developed to measure local chemiluminescence near the spark gap in a practical spark-ignition (SI) engine in order to study the development of the initial flame kernel, flame front structure, transient phenomena, and the correlation between the initial flame kernel structure and cyclic variation in the flame front structure, which influences engine performance directly. The sensor consists of a commercial instrumented spark plug with small Cassegrain optics and an optical fiber. The small Cassegrain optics were developed to measure the local chemiluminescence intensity profile and temporal history of OH*, CH*, and C 2* at the flame front formed in a turbulent premixed flame in an SI engine. A highresolution monochromator with an intensified chargecoupled device (ICCD) and spectroscopy using optical filters and photomultiplier tubes (PMTs) were used to measure the time-series of the three radicals, as well as the in-cylinder pressure. Measurements were made at different engine speeds in an unmodified 223-cc practical SI engine fueled with gasoline. Stable data were obtained over several hours with little noise, and were of the same quality as data from a small M5-type sensor installed instead of a pressure transducer. The relationships between the radical intensities and indicated mean effective pressure (IMEP) were examined and typical cyclic variation was measured at speeds over 7,000 rpm. The behavior of the initial flame was followed from its arrival at the measurement point. The arrival time was faster and IMEP was larger at stoichiometry than under other air/fuel (A/F) conditions. Copyright © 2005 SAE International.

    DOI: 10.4271/2005-01-0644

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  • In-spark-plug sensor for analyzing the initial flame and its structure in an SI engine

    Yuji Ikeda, Atsushi Nishiyama, Nobuyuki Kawahara, Eiji Tomita, Shigeyuki Arimoto, Akira Takeuchi

    SAE Technical Papers   2005年

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    記述言語:英語  

    An in-spark-plug flame sensor was developed to measure local chemiluminescence near the spark gap in a practical spark-ignition (SI) engine in order to study the development of the initial flame kernel, flame front structure, transient phenomena, and the correlation between the initial flame kernel structure and cyclic variation in the flame front structure, which influences engine performance directly. The sensor consists of a commercial instrumented spark plug with small Cassegrain optics and an optical fiber. The small Cassegrain optics were developed to measure the local chemiluminescence intensity profile and temporal history of OH*, CH*, and C 2* at the flame front formed in a turbulent premixed flame in an SI engine. A highresolution monochromator with an intensified chargecoupled device (ICCD) and spectroscopy using optical filters and photomultiplier tubes (PMTs) were used to measure the time-series of the three radicals, as well as the in-cylinder pressure. Measurements were made at different engine speeds in an unmodified 223-cc practical SI engine fueled with gasoline. Stable data were obtained over several hours with little noise, and were of the same quality as data from a small M5-type sensor installed instead of a pressure transducer. The relationships between the radical intensities and indicated mean effective pressure (IMEP) were examined and typical cyclic variation was measured at speeds over 7,000 rpm. The behavior of the initial flame was followed from its arrival at the measurement point. The arrival time was faster and IMEP was larger at stoichiometry than under other air/fuel (A/F) conditions. Copyright © 2005 SAE International.

    DOI: 10.4271/2005-01-0644

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  • In-situ unburned gas temperature measurement in a spark ignition engine using laser interferometry

    Nobuyuki Kawahara, Eiji Tomita, Kenji Ohnishi, Kazuhiro Goto

    SAE Technical Papers   2005年

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    記述言語:英語  

    A heterodyne interferometry system with a fiber-optic sensor was developed to measure the temperature history of unburned gas in a spark-ignition engine. A polarization-preserving fiber and metal mirror were used as the fiber-optic sensor to deliver the test beam to and from the measurement region. This fiber-optic sensor can be assembled in an engine cylinder head without a lot of improvements of an actual engine. Adjustment system in the sensor was revised to face the distributed index lens with metal mirror. Before the flame arrived at the developed fiber-optic sensor, measured temperature was almost same with the temperature history after the spark, assuming that the process that changes the unburned gas is adiabatic. In situ unburned gas temperature measurements before knocking in a commercially produced SI engine can be carried out using developed fiber-optic heterodyne interferometry system. Although the heterodyne interferometry with the developed fiber-optic sensor provides the mean temperature along the line of sight, the feasibility of our system was sufficient to be applied to temperature history measurement of an unburned gas compressed by flame propagation in an engine cylinder. The developed heterodyne interferometry with fiber-optic sensor has a good feasibility to measure the unburned gas temperature history in the commercially produced spark-ignition engine. Copyright © 2005 SAE International.

    DOI: 10.4271/2005-01-0646

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  • Concentration Measurement of Unburned Hydrocarbons in Exhaust Gas from an SI Engine by Using 3.392 micrometer Absorption Method

    Tomita, E, Kawahara, N

    6th JSME-KSME Thermal Engineering Conference,   2005年

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  • PIV Measurement of High-Pressure Swirl Injector Spray near Nozzle Exit for DISI Engine

    Kawahara, N. Tomita, E. Fukuda, D. Sumida, M

    7th International Congress on Optical Particle Characterization,   2004年

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  • Fuel breakup near nozzle exit of high-pressure swirl injector for gasoline direct injection engine

    Nobuyuki Kawahara, Eiji Tomita, Daisuke Kasahara, Takashi Nakayama, Mamoru Sumida

    SAE Technical Papers   2004年

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    記述言語:英語  

    Experimental investigations of fuel breakup very close to nozzle of practical high-pressure swirl injector, which is used in gasoline direct injection (GDI) engine, were carried out. In GDI engines, fuel is directly injected into cylinder therefore the spray characteristics and mixture formation are of primary importance. In this research, visualizations of primary spray formation process were demonstrated using a high-speed video camera (maximum speed: 1Mfps) with a long-distance microscope. Initial state and development of the spray were discussed under the different injection pressure condition. During the injection period, the length and thickness of the liquid sheet, which is produced from the nozzle exit, were measured using Ar-ion laser sheet and high-speed camera. Primary spray structure and behavior of liquid sheet, especially surface wave of liquid sheet, at nozzle exit were discussed using obtained images. Three main conclusions were drawn from this study. (1) It has been shown that the liquid fuel column without swirl motion was injected as a compact jet at the beginning of the injection. During the injection period, the spray indicates the quasi-steady state mode. (2) Liquid film sheet has a ligament structure. Using Ar-ion laser sheet and high-speed camera, length and thickness of the liquid sheet can be measured. Higher injection pressure causes thinner thickness and shorter length of liquid sheet. (3) Surface waves of liquid sheet can be recognized. Higher injection pressure makes larger wavelength of surface waves of liquid sheet of swirl injector. Copyright © 2004 SAE International.

    DOI: 10.4271/2004-01-0542

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  • 3.392μm赤外吸収法を用いたエンジンシリンダ内点火栓近傍炭化水素系燃料濃度計測-実用機関への適用-

    冨田栄二, 河原伸幸, 西山淳, 重永真宏

    日本機械学会論文集 (B編),   70 ( 690 )   518 - 524   2004年

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    記述言語:日本語  

    An infrared absorption method was used to determine the fuel concentration with a 3.392 μm He-Ne laser. The effects of pressure and temperature on the molar absorption coefficients of hydrocarbon fuels were clarified, so that it increased with increasing temperature and decreased with increasing pressure. Molar absorption coefficient of multi-component fuel like gasoline can be estimated using molar absorption coefficient of each component and considering mass balance. By exchanging an ordinary spark-plug for &amp; spark-plug with a developed sensor in which light can pass through mixture in the combustion chamber, successive measurement of fuel concentration was performed in a spark-ignition engine. The effects of liquid droplets, mechanical vibration, and other gas like H2O on measurement accuracy were discussed.

    DOI: 10.1299/kikaib.70.518

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  • 3.392μm赤外吸収法を用いたエンジンシリンダ内点火栓近傍炭化水素系燃料濃度計測-メタン〜空気均一予混合気による検討-

    冨田栄二, 河原伸幸, 重永真宏, 西山 淳

    日本機械学会論文集 (B編),   70 ( 690 )   511 - 517   2004年

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    記述言語:日本語  

    A fiber optic system linked to the optical sensor installed in the spark plug, in which light can pass through the combustion chamber, was developed to determine the fuel concentration near the spark-plug successively using an infrared absorption method. A He-Ne laser with a wavelength of 3.392 μm that coincides with the absorption line of hydrocarbons was used as a light source. By exchanging an ordinary spark plug into this spark plug with the optical sensor, sucessive measurement of fuel concentration before the spark timing near the spark-plug was performed in a spark-ignition engine inducted with homogeneously mixed method methane-air. The fuel concentration was determined from law of Lambert-Beer in consideration for the effects of pressure and temperature on molar absorption coefficient of methane.

    DOI: 10.1299/kikaib.70.511

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  • Development of Combustion Facility of Constant-Volume Vessel for Investigating Combustion Characteristics of Banker Fuel Oil

    Tomita, E. *Kawahara, N. Ohuchi, T. Imahashi, T. Takasu, I. Morinaka, H. Yokota, K

    24th CIMAC World Congress 2004,   2004年

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  • Combustion Characteristics and Performance of Supercharged Single Cylinder Natural Gas Engine Ignited with Pilot Injection of Diesel Fuel

    Tomita, E. *Kawahara, N. Kinoshita, Y. Komoda, T. Sakane, A

    FISITA 2004,   2004年

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  • Homogeneous Charge Compression Ignition Combustion with Dimethyl Ether (Effect of Stratified Fuel Concentration)

    Kawahara, N. Tomita, E. Arimoto, S

    FISITA 2004,   2004年

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  • Time-series A/F Analysis in a SI Engine by Micro-Local Chemiluminescence Technique

    Ikeda, Y. *Kawahara, N. Tomita, E

    Proc. of 6th COMODIA 2004,   2004年

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  • Liquid Sheet Break-up of High-Pressure Swirl Injector for DISI Engines

    Kawahara, N. Tomita, E. Kasahara, D. Sumida, M

    Proc. of 6th COMODIA 2004,   2004年

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  • Temperature Measurements of Laminar Propane/Air Premixed Flame using Detailed OH* Spectra Intensity Ratio

    Ikeda, Y. Kurahashi, T. *Kawahara, N. Tomita, E

    12th Int. Symp. on Application of Laser Techniques on Fluid Mechanics,   2004年

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  • Measurement of Unburned Gas Temperature in an SI Engine Using Fiber-Optic Laser Interferometry

    Kawahara, N. Tomita, E. Takasu, K. Goto, K

    12th Int. Symp. on Application of Laser Techniques on Fluid Mechanics,   2004年

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  • Spectrum Analysis of Chemiluminescence in HCCI Combustion with Dimethyl Ether

    Kawahara, N. Tomita, E

    Lean Combustion Technology II, Engineering Foundation   2004年

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  • Diluted and Stoichiometric Combustion of Dual Fuel (Methane and Gas Oil) Engine with HCCI Concept

    Tomita, E, Kawahara, N

    Lean Combustion Technology II, Engineering Foundation   2004年

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  • 定容容器内燃料-空気混合気の燃焼に及ぼす旋回乱流場および層状燃料濃度場の影響(第2報,燃料濃度場および乱流場が燃焼特性に及ぼす影響

    西山淳, 冨田栄二, 河原伸幸, 吉山定見, 浜本嘉輔

    日本機械学会論文集 (B編),   70 ( 692 )   1092 - 1099   2004年

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    記述言語:日本語  

    A swirling flow and rich fuel concentration near the center were produced in a vessel by tangentially charging air and fuel injection. Propane was used as fuel. Fuel concentration distribution was measured with laser induced fluorescence (LIF) method using acetone as a tracer. It was confirmed that the center-rich stratified fuel concentration was produced. In order to estimate the pattern of the fuel concentration field, the Gaussian fitting method was applied to the equivalence ratio profile. Fuel distribution history obtained from LIF measurement agreed with the calculation result using axisymmetric diffusion equation. The initial stage of combustion was greatly affected by the fuel concentration distribution in the vicinity of the spark location. The stronger turbulence intensity accelerated combustion and main combustion became shorter under the same fuel distribution conditions.

    DOI: 10.1299/kikaib.70.1092

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  • in Situ Fuel Concentration Measurement near Spark Plug by 3.39 m Infrared Absorption Method (Application to a Port Injected Lean-Burn Engine)

    Nishiyama, A. *Kawahara, N. Tomita, E. Fujiwara, M. Ishikawa, N. Kamei, K. Nagashima, K

    SAE 2004 World Congress,   2004年

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    記述言語:英語  

    In this study, a spark plug sensor for in-situ fuel concentration measurement was applied to a port injected lean-burn engine. Laser infrared absorption method was employed and a 3.392 μm He-Ne laser that coincides with the absorption line of hydrocarbons was used as a light source. In this engine, the secondary valve lift height of intake system was controlled to obtain appropriate swirl and tumble flow in order to achieve lean-burn with the characteristics of intake flow. For such in-cylinder stratified mixture distribution, the fuel concentration near the spark plug is very important factor that affects the combustion characteristics. Therefore, the mixture formation process near the spark plug was investigated with changing fuel injection timing. Under the intake stroke, the timing that fuel passed through near the spark plug depended largely on the fuel injection timing. Under the compression stroke, mixture formation process near the spark plug indicated different characteristics with injection timings. As the injection timing was retarded, rich mixture remained near the top of the combustion chamber. Furthermore, the relation between the fuel concentration near the spark plug and the combustion characteristics was discussed. The initial combustion became faster and the coefficient of variation in IMEP became lower as the rich mixture existed near the spark plug. Copyright © 2004 SAE International.

    DOI: 10.4271/2004-01-1353

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  • LDV,PDAの基礎と応用

    河原伸幸

    No.04-45講習会基礎教育講習会‐エンジンにおける実験・計測の基礎と応用(その 9),日本機械学会エンジンシステム部門,   pp.11-18   2004年

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  • 赤外線吸収法を利用した点火栓近傍燃料濃度センサの開発

    冨田栄二, 河原伸幸

    工業加熱,   Vol.41, No.3, pp.10-16   2004年

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  • レーザ計測によるエンジン内諸現象の観察

    河原伸幸

    若手研究最前線,エンジンテクノロジー,   No.30,pp.52-59   2004年

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  • LDV,PDAの基礎と応用

    河原伸幸

    No.03-101講習会基礎教育講習会‐エンジンにおける実験・計測の基礎と応用(その 8),日本機械学会エンジンシステム部門,   pp.11-18   2004年

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  • インジェクタのノズル近傍における噴霧形成過程の可視化

    河原伸幸

    第12回微粒化フォーラム「噴霧特性の測定原理と実習」テキスト,   pp.37-43   2004年

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  • Real Time HC Concentration Measurement in Exhaust Gas from A Spark-Ignition Engine by Using 3.392 m Absorption Method

    Tomita, E, Kawahara, N

    Journal of KONES International Combustion Engines,   2004年

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  • Characteristics of Combustion and Exhaust Emissions in a Dual Fuel Engine with HCCI Concept -Diluted and Stoichiometric Combustion-

    Tomita, E, Kawahara, N

    Homogeneous Charge Compression Ignition Symposium   2004年

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  • In situ Measurement of Hydrocarbon Fuel Concentration near a Spark Plug in an Engine Cylinder by 3.392 m Infrared Laser Absorption Method - Application to Actual Engine -

    Tomita, E, Kawahara, N, Nishiyama, A, Shigenaga, M

    Measurement Science and Technology   14 ( 8 )   1357 - 1363   2003年8月

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    記述言語:英語  

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  • Homogeneous charge compression ignition combustion with dimethyl ether - Spectrum analysis of chemiluminescence

    Nobuyuki Kawahara, Eiji Tomita, Hisashi Kagajyo

    SAE Technical Papers   2003年

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    記述言語:英語  

    Homogeneous Charge Compression Ignition (HCCI) combustion with dimethyl ether has been carried out in a single cylinder engine with a transparent piston. The engine was operated at 800 rpm with a wide-open throttle. The intake-premixed mixture was preheated with an electric heater to promote auto-ignition. HCCI combustion with dimethyl ether indicates multi-stage heat releases. Investigations were conducted with visualization of combustion in the cylinder and detailed and temporal spectroscopic measurements using spectrometer. In order to understand reaction mechanism of auto-ignition and combustion mechanism in HCCI engine, spectrum analysis of chemiluminescence was carried out. Three main conclusions were drawn from this study. (1) Spectrum from chemiluminescence at low temperature oxidation was obtained successfully using developed optical fiber probe. (2) Emitting lights from HCHO according to Emeléous's cool flame bands appear at low temperature reaction. (3) During the main heat release, the CO-O recombination spectrum was strong. There was a strong correlation between rate of heat release and the CO-O recombination spectrum. Copyright © 2003 Society of Automotive Engineers of Japan, Inc.

    DOI: 10.4271/2003-01-1828

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  • 水素を用いた内燃機関の新燃焼法に関する研究

    河原伸幸

    (財)実吉奨学会,平成13年度研究報告集   Vol.20, pp.35-38   2003年

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  • LDA,PDAの基礎と応用(応用例:噴霧粒子径および速度の同時計測など),

    河原伸幸

    第89回講習会エンジニアのための基礎からのレーザ応用最新技術,日本機械学会中国四国支部   pp.23-30   2003年

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  • 多種噴霧/工業分野

    河原伸幸

    微粒化   Vol.12, No.39, pp.105-107   2003年

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  • In-Situ Fuel Concentration Measurement with Optical Spark Plug Sensor by 3.39 m Infrared Laser Absorption Method

    Nishiyama, A, Kawahara, N, Tomita, E, Shigenaga, M

    19th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS)   2003年

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  • Effects of Swirl Flow and Inhomogeneous Concentration Fields on Combustion of Propane-Air Mixture in a Constant-Volume Vessel

    Tomita, E, Nishiyama, A, Kawahara, N

    19th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS)   2003年

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  • Analysis of Two-Stage Heat Release in HCCI Combustion with Dimethyl Ether

    Kawahara, N, Tomita, E, Kagajyo, H

    19th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS)   2003年

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  • Microscopic Observation of Primary Spray Structure of High-Pressure Swirl Injector for Gasoline Direct Injection Engine

    Kawahara, N, Tomita, E, Nakayama, T, Sumida, M

    The 9th Int. Conf. on Liquid Atomization and Spray Systems (ICLASS 2003),   2003年

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  • In-Situ Fuel Concentration Measurement near Spark Plug by 3.392 μm Infrared Absorption Method (Application to Spark Ignition Engine)

    Nishiyama, A. *Kawahara, N. Tomita, E

    SAE Transactions - Journal of Engines,   2003年

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    記述言語:英語  

    This study measured the fuel concentration near a spark plug using a laser infrared absorption method. An IR spark plug sensor with a double-pass measurement length was developed. A He-Ne laser with a wavelength of 3.392 μm, which coincides with the absorption line of hydrocarbons, was used as the light source. In order to confirm the measurement accuracy, the concentrations of a methane-air mixture were measured in a compression-expansion engine. Then, the IR spark plug sensor was used for measurements in a 4-stroke spark-ignition engine fuelled with isooctane. The air/fuel ratio measured using this system clearly agreed with the mean air/fuel ratio. Copyright © 2003 SAE International.

    DOI: 10.4271/2003-01-1109

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  • メタン/ 軽油ディーゼル機関の燃焼・排気特性に及ぼす早期噴射およびEGRの影響

    冨田栄二, 河原伸幸, 朴振宇, 山口良一

    日本機械学会論文集B編   69 ( 680 )   988 - 994   2003年

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    記述言語:日本語  

    Dual fuel natural gas engines have been studied for the purpose of near future engine. This study focuses on the effect of early injection of light oil and exhaust gas recirculation (EGR) fueled with methane from an inlet pipe on characteristics of combustion and exhaust emissions. The injection timing was changed from TDC to 50 degrees before the TDC. In the early injection timing, smoke was never seen and hydrocarbons were smaller compared with those at the normal injection timing. However, the combustion becomes too early to obtain an appropriate torque when the equivalence ratio increases. Then, moderate nitrogen dilution was very effective to retard the combustion with lower NOx, higher thermal efficiency and almost the same hydrocarbons and carbon monoxide. And it was found that the engine operates even under the condition of stoichiometric mixture.

    DOI: 10.1299/kikaib.69.988

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  • Transient temperature measurement of unburned gas in an engine cylinder using laser interferometry with a fiber-optic sensor

    Nobuyuki Kawahara, Eiji Tomita, Mitsuru Ichimiya, Kouji Takasu, Naoki Tsuchida, Kazuhiro Goto

    SAE Technical Papers   2003年

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    記述言語:英語  

    A heterodyne interferometry system with a fiber-optic sensor was developed to measure the temperature history of unburned gas in an engine cylinder. A polarization-preserving fiber and metal mirror were used as the fiber-optic sensor to deliver the test beam to and from the measurement region. This fiber-optic sensor can be assembled in the engine cylinder or the cylinder head without a lot of improvements of an actual engine. The feasibility of our system was sufficient to be applied to temperature history measurement of an unburned gas compressed by flame propagation in an engine cylinder. The resolution of the temperature measurement is approximately 0.7 K, and is dependent on both the sampling clock speed of the A/D converter and the length of the measurement region. Copyright © 2003 Society of Automotive Engineers of Japan, Inc.

    DOI: 10.4271/2003-01-1799

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  • 定容容器内燃料‐空気混合気の燃焼に及ぼす旋回乱流場および層状燃料濃度場の影響(第1報,層状混合気の燃焼特性)

    西山淳, 冨田栄二, 河原伸幸, 吉山定見, 浜本嘉輔

    日本機械学会論文集B編   69 ( 687 )   2531 - 2538   2003年

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    記述言語:日本語  

    A swirling flow was produced in a vessel by tangentially charging fuel-air mixture or air. Rich fuel concentration was formed near the center of the vessel by fuel injection. Mixture was ignited at the center of the vessel. Various swirling flow field and fuel concentration field were made by changing the mean equivalence ratio in the vessel, the timing of charging mixture and fuel injection. The mean equivalence ratio in the vessel was changed from 0.20 to 0.84. Appropriate mixture stratification enabled initial combustion to be faster than that of homogeneous mixture. Under the lean condition, the combustion efficiency was lower and flame could not propagate in the lean mixture region near the wall as the homogeneity of the mixture became larger. In the case of the slowest swirling condition, initial combustion and initial flame propagation became slower due to rich mixture near the center of the chamber.

    DOI: 10.1299/kikaib.69.2531

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  • In situ Measurement of Hydrocarbon Fuel Concentration near a Spark Plug in an Engine Cylinder by 3.392 m Infrared Laser Absorption Method - Discussion of Applicability with Homogeneous Methane-Air Mixture -

    Tomita, E, Kawahara, N, Shigenaga, M, Nishiyama, A, Dibble, R

    Measurement Science and Technology   14 ( 8 )   1350 - 1356   2003年

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    記述言語:英語  

    A fibre optic system was developed to determine the fuel concentration near a spark plug using an infrared absorption method. The system was linked to an optical sensor installed in the spark plug, from which light could pass through the combustion chamber. By using this modified spark plug, successive measurements of the fuel concentration near the spark plug before ignition were performed in a spark-ignition engine burning homogeneously mixed methane-air. The fuel concentration was determined from the Lambert-Beer law by considering the dependence of the methane molar absorption coefficient on pressure and temperature. Three main conclusions were drawn from this study. First, the methane molar absorption coefficient was greater for lower pressures and decreased with increasing temperature and pressure above atmospheric pressure. The temperature and pressure effects were offset by each other, since the temperature effects were positive and the pressure effects were negative. Second, precise time-series data for the local fuel concentration were obtained by considering the in-cylinder pressure and temperature from an estimate of the methane molar absorption coefficient. And third, the measured air/fuel ratio near the spark plug before ignition agreed with the preset value when the developed optical sensor was used under motoring and firing conditions.

    DOI: 10.1088/0957-0233/14/8/321

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  • 光ヘテロダイン干渉法による未燃焼ガス温度変化計測

    河原伸幸, 冨田栄二, 鎌倉寛

    日本機械学会論文集B編   69 ( 677 )   229 - 235   2003年

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    記述言語:日本語  

    This paper demonstrates an application of the optical heterodyne interferometry, a laser-based technique for measuring the temperature history of gas in combustion devices, such as internal combustion engines. The technique is based on refractive index measurements using laser interferometry along a line of sight. The temperature history of gas can be determined from the pressure history in the combustion chamber, the gas composition, and the laser interference intensity. A polarization-preserving fiber was used to deliver the test beam to and from the test section to improve the feasibility of the system as a sensor probe. The temperature of the unburned mixture in the end-gas region of a constant volume combustion chamber and in an engine cylinder were measured during flame propagation. The accuracy of the measurement and the feasibility of this system are discussed. The measurement accuracy of our system was sufficient to be applied to temperature history measurement of an unburned gas compressed by flame propagation in an engine cylinder. The uncertainty of this method is within ± 10 K. The resolution of the temperature measurement was approximately 0.5 K, and was dependent upon both the sampling clock speed of the A/D converter and the length of the test section. This optical heterodyne interferometry system may also be used for other applications that require a fast response time to measure the density and pressure of a gas, and thereby obtain a transient temperature record.

    DOI: 10.1299/kikaib.69.229

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  • In situ measurement of hydrocarbon fuel concentration near a spark plug in an engine cylinder using the 3.392 μm infrared laser absorption method: Application to an actual engine

    Eiji Tomita, Nobuyuki Kawahara, Atsushi Nishiyama, Masahiro Shigenaga

    Measurement Science and Technology   14 ( 8 )   1357 - 1363   2003年

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    記述言語:英語  

    An infrared absorption method with a 3.392 umm He-Ne laser was used to determine the hydrocarbon fuel concentration near the spark plug in a spark-ignition engine. Iso-octane was used for the fuel. The pressure and temperature dependence of the molar absorption coefficient was clarified. The molar absorption coefficients of a multi-component fuel such as gasoline were estimated by using the coefficient of each component and considering the mass balance. A sensor was developed and installed in a spark plug, which was substituted in place of an ordinary spark plug in a spark-ignition engine. Light can pass from the sensor through the engine cylinder to measure the fuel concentration. The effects of liquid droplets inside the engine cylinder, mechanical vibrations and other gases such as H2O and CO2 on the measurement accuracy were considered. Four main conclusions were drawn from this study. First, the pressure and temperature effects on the molar absorption coefficient of liquid fuel vapour were determined independently in advance using a constant-volume vessel. The pressure and temperature dependence of the molar absorption coefficient was determined under engine firing conditions. Second, the molar absorption coefficients of a multi-component hydrocarbon fuel such as gasoline were estimated by considering the molar fraction of each component. Third, in situ measurements of the hydrocarbon fuel concentration in an actual engine were obtained using the spark plug sensor and the molar absorption coefficient of iso-octane. The concentration near the spark plug just before ignition was almost in agreement with the mean value that was obtained from the measurement of the flow rate made with a burette, which represented the mean value averaged over many cycles. And fourth, no liquid droplets were observed at near-idling conditions. The effects of other gases, such as CO, CO2 and H2O, can be neglected.

    DOI: 10.1088/0957-0233/14/8/322

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  • Combustion and Exhaust Emissions in a Hydrogen Fueled Engine Ignited with Light Oil

    Tomita, E, Kawahara, N, Piao, Z, Yamaguchi, R

    Proc. of The 6th ASME-JSME Thermal Engineering Joint Conference   2003年

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  • In-situ fuel concentration measurement near spark plug by 3.39 MM infrared absorption method (development of a double-pass optical sensor)

    A. Nishiyama, N. Kawahara, E. Tomita

    International Symposium on Combustion Abstracts of Works-in-Progress Posters   169   2002年12月

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    It is very important to know the hydrocarbon fuel concentration near the spark plug. The possibility of the concentration measurement near the spark plug using in-situ IR absorption method was presented. The fuel concentration near the spark plug was measured using an optical sensor with sapphire rods. A new optical sensor with double-pass measurement length was developed to increase the measurement accuracy. The light source with wavelength of 3.392 μm was introduced into an optical fiber and guided to a spark plug. This optical sensor was constructed by modifying a commercially available instrumented spark plug. Original is an abstract.

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  • Flame propagation and combustion characteristics of stratified charge propane-air mixture with swirling flow in a constant-volume vessel

    A. Nishiyama, E. Tomita, N. Kawahara, S. Yoshiyama, Y. Hamamoto

    International Symposium on Combustion Abstracts of Works-in-Progress Posters   207   2002年12月

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    The flame propagation and the combustion characteristics of stratified fuel concentration field were studied using a cylindrical constant volume vessel. A swirling fuel-air mixture was produced in the vessel. A rich fuel concentration was formed near the center of the vessel by the injection of propane and lean mixture near the wall. The gas flow field was obtained with a laser Doppler velocimeter in advance. The pressure history in the combustion chamber was analyzed to determine the combustion characteristics. The flame could propagate and the combustion occurred even in an ultra lean mixture of equivalence ratio of 0.3:1 in total. As the fuel concentration near the spark location approximates stoichiometric mixture ratio, flame propagation of the initial stage of the combustion became faster. When stratified mixtures with the same pattern of fuel concentration but different turbulence intensities were considered, the main combustion period decreased with turbulence intensity, since the burning velocity also increased. Original is an abstract.

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  • Fiber-optic heterodyne interferometry temperature measurement of unburned gas in a HCCI engine fueled with DME

    Nobuyuki Kawahara, Eiji Tomita, Mitsuru Ichimiya

    International Symposium on Combustion Abstracts of Works-in-Progress Posters   170   2002年12月

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    Various global environmental issues are related to the use of internal combustion engines, including air pollution and energy concerns. With homogeneous charge compression ignition (HCCI) engine, it is possible to operate with ultra lean premixed mixtures and to lead low NOx and soot-particle emissions. The temperature of the unburned mixture in a HCCI engine, fueled with dimethyl ether, was measured using fiber-optic heterodyne interferometry along a line of sight. The measurement accuracy of the developed system was sufficient to determine the temperature history of unburned mixture in HCCI operation. The uncertainty of this method was within ± 15K. The resolution of temperature measurements was ∼ 0.5 K, and depended on the sampling clock speed of the A/D converter and the length of the test section. Original is an abstract.

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  • Unburned gas temperature measurement in a spark-ignition engine using fibre-optic heterodyne interferometry

    N Kawahara, E Tomita, H Kamakura

    MEASUREMENT SCIENCE AND TECHNOLOGY   13 ( 1 )   125 - 131   2002年1月

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    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    A fibre-optic heterodyne interferometry system was developed to obtain the temperature histories of an unburned mixture with high temporal resolution non-intrusively. In laser interferometry, the effective optical path length of the test beam changes with the gas density and corresponding changes of the refractive index. Therefore, the temperature history of an unburned gas can be determined from the pressure and phase shift of the heterodyne signal. A polarization-preserving fibre is used to deliver the test beam to and from the test section, to improve the feasibility of the system as a sensor probe. The temperature of the unburned mixture in the end-gas region of a constant-volume combustion chamber and in an engine cylinder was measured during flame propagation. The accuracy of the measurements and the feasibility of this system are discussed. The measurement accuracy of our system was sufficient to be applied to temperature history measurement of an unburned gas compressed by flame propagation in a constant-volume combustion chamber. The uncertainty of this method is within +/-10 K. The resolution of the temperature measurement is approximately 0.5 K, and is dependent on both the sampling clock speed of the A/D converter and the length of the test section, This fibre-optic heterodyne interferometry system can also be used for other applications that require a transient temperature with a fast response time.

    DOI: 10.1088/0957-0233/13/1/316

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  • In situ fuel concentration measurement near spark plug in spark-ignition engines by 3.39 μm infrared laser absorption method

    Eiji Tomita, Nobuyuki Kawahara, Sadami Yoshiyama, Akihiko Kakuho, Teruyuki Itoh, Yoshisuke Hamamoto

    Proceedings of the Combustion Institute   29 ( 1 )   735 - 741   2002年

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    記述言語:英語   出版者・発行元:Elsevier Ltd  

    Recently, improving the thermal efficiency and reducing the exhaust emissions of internal combustion engines have become crucial. To this end, it is important to determine the fuel concentration in the vicinity of the spark plug near the spark timing, because initial combustion affects the subsequent main combustion in spark-ignition engines. In this study, a fiber optic system linked to an optical sensor installed in the spark plug, by means of which light can pass through the combustion chamber, was developed to determine the fuel concentration near the spark plug using an IR absorption method. A He-Ne laser with a wavelength of 3.39 μm that coincides with the absorption line of hydrocarbons was used as a light source. By exchanging an ordinary spark plug for this spark plug with the optical sensor, successive measurement of fuel concentration before the spark timing near the spark plug was performed in a port-injection spark-ignition engine fueled with iso-octane under the firing condition. The effects of pressure and temperature on the molar absorption coefficient of fuel were clarified in advance. The air/fuel ratio averaged for many cycles near the spark plug with this optical system agreed with that measured with a buret, which represented the mean value averaged over a protracted period. Next, this sensor was applied to determine the air/fuel ratio quantitatively in a direct-injection gasoline engine. As a result, it was clarified that the air/fuel ratio and its standard deviation near the spark plug have a strong relationship to stable engine operation.

    DOI: 10.1016/S1540-7489(02)80094-3

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  • レーザ干渉法を利用した高応答・高精度温度センサの開発

    河原伸幸

    新エネルギー・産業技術総合開発機構,平成12年度即効産業技術研究助成事業,研究成果報告書   2002年

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  • Effects of EGR and early injection of diesel fuel on combustion characteristics and exhaust emissions in a methane dual fuel engine

    Eiji Tomita, Nobuyuki Kawahara, Zhenyu Piao, Ryoichi Yamaguchi

    SAE Technical Papers   2002年

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    記述言語:英語  

    A dual fuel engine fueled with methane from an inlet port and ignited with diesel fuel was prepared. This study focuses on the effects of early injection and exhaust gas recirculation (EGR) on the characteristics of combustion and exhaust emissions. The injection timing was changed between TDC and 50 degrees before the TDC. In the early injection timing, smoke was never seen and hydrocarbons were smaller compared with those at the normal injection timing. However, the combustion becomes too early to obtain an appropriate torque when the equivalence ratio increases. Then, moderate EGR was very effective to force the combustion to retard with lower NOx, higher thermal efficiency and almost the same hydrocarbons and carbon monoxide. The engine operated even under the condition of stoichiometric mixture. Copyright © 2002 SAE International.

    DOI: 10.4271/2002-01-2723

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  • Effects of EGR and early injection of diesel fuel on combustion characteristics and exhaust emissions in a methane dual fuel engine

    Eiji Tomita, Nobuyuki Kawahara, Zhenyu Piao, Ryoichi Yamaguchi

    SAE Technical Papers   2002年

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    記述言語:英語  

    A dual fuel engine fueled with methane from an inlet port and ignited with diesel fuel was prepared. This study focuses on the effects of early injection and exhaust gas recirculation (EGR) on the characteristics of combustion and exhaust emissions. The injection timing was changed between TDC and 50 degrees before the TDC. In the early injection timing, smoke was never seen and hydrocarbons were smaller compared with those at the normal injection timing. However, the combustion becomes too early to obtain an appropriate torque when the equivalence ratio increases. Then, moderate EGR was very effective to force the combustion to retard with lower NOx, higher thermal efficiency and almost the same hydrocarbons and carbon monoxide. The engine operated even under the condition of stoichiometric mixture. Copyright © 2002 SAE International.

    DOI: 10.4271/2002-01-2723

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  • In situ fuel concentration measurement near spark plug in spark-ignition engines by 3.39 μm infrared laser absorption method

    Eiji Tomita, Nobuyuki Kawahara, Sadami Yoshiyama, Akihiko Kakuho, Teruyuki Itoh, Yoshisuke Hamamoto

    Proceedings of the Combustion Institute   29 ( 1 )   735 - 741   2002年

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    記述言語:英語  

    Recently, improving the thermal efficiency and reducing the exhaust emissions of internal combustion engines have become crucial. To this end, it is important to determine the fuel concentration in the vicinity of the spark plug near the spark timing, because initial combustion affects the subsequent main combustion in spark-ignition engines. In this study, a fiber optic system linked to an optical sensor installed in the spark plug, by means of which light can pass through the combustion chamber, was developed to determine the fuel concentration near the spark plug using an IR absorption method. A He-Ne laser with a wavelength of 3.39 μm that coincides with the absorption line of hydrocarbons was used as a light source. By exchanging an ordinary spark plug for this spark plug with the optical sensor, successive measurement of fuel concentration before the spark timing near the spark plug was performed in a port-injection spark-ignition engine fueled with iso-octane under the firing condition. The effects of pressure and temperature on the molar absorption coefficient of fuel were clarified in advance. The air/fuel ratio averaged for many cycles near the spark plug with this optical system agreed with that measured with a buret, which represented the mean value averaged over a protracted period. Next, this sensor was applied to determine the air/fuel ratio quantitatively in a direct-injection gasoline engine. As a result, it was clarified that the air/fuel ratio and its standard deviation near the spark plug have a strong relationship to stable engine operation.

    DOI: 10.1016/S1540-7489(02)80094-3

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  • Transient temperature measurement of unburned gas using optic heterodyne interferometry

    N Kawahara, E Tomita, H Kamakura

    LASER TECHNIQUES FOR FLUID MECHANICS   157 - 172   2002年

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    記述言語:英語   出版者・発行元:SPRINGER-VERLAG BERLIN  

    Optical heterodyne interferometry was validated to measure the transient temperature of a gas by comparing the temperature history of unburned gas in a combustion chamber, caused by compression due to flame propagation, obtained by the heterodyne interferometry with temperature obtained by assuming adiabatic change. When the density of gas changes, the effective optical path length of the test beam changes with corresponding changes of the refractive index. Therefore, the temperature history of the gas can be determined by measuring the pressure and the phase shift of the interference signal. As a result, it is clearly recognized that a non-intrusive measurement in the transient gas temperature was made successfully by the optical heterodyne interferometry. The resolution of the temperature measurement is approximately 0.5 K, and is dependent upon both the sampling clock speed of the A/D converter and the length of the test section. Moreover, a polarization-preserving fiber was used to deliver the test beam to and from the test section to improve the feasibility of the system as a sensor probe. It may also be applied to other system requiring fast response density and temperature measurement of a gas, the latter necessitating a simultaneous record of transient pressure.

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  • In-situ fuel concentration measurement near spark plug in spark-ignition engines by 3.39 μM infrared laser absorption method

    Eiji Tomita, Nobuyuki Kawahara, Sasdami Yoshiyama, Akihiko Kakuho, Teruyki Itoh, Yoshisuke Hamamoto

    International Symposium on Combustion Abstracts of Accepted Papers   29 ( 1 )   735 - 741   2002年

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    記述言語:英語  

    Improving thermal efficiency and reducing the exhaust emissions of internal combustion engines have become crucial. Thus, it is important to determine the fuel concentration in the vicinity of the spark plug near the spark timing because initial combustion affects the following main combustion in spark-ignition engines. A fiber optic system linked to the optical sensor installed in the spark plug, by means of which light could pass through the combustion chamber, was developed to determine the fuel concentration near the spark plug using an IR absorption method. A He-Ne laser with a wavelength of 3.39 μm coinciding with the absorption line of hydrocarbons was utilized as a light source. By exchanging an ordinary spark plug for this spark plug with the optical sensor, successive measurement of fuel concentration before the spark timing near the spark plug was carried out in a port injection spark-ignition engine fueled with isooctane under the firing condition. The air/fuel ratio averaged for many cycles near the spark plug with this optical system agreed with that measured with a buret, which represented the mean value averaged over a protracted period. This sensor was also applied to determine air /fuel ratio quantitatively in a direct injection gasoline engine. As a result, it was clarified that the air/fuel ratio and its standard deviation near the spark plug had a strong relationship to the stable engine operation. Original is an abstract.

    DOI: 10.1016/S1540-7489(02)80094-3

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  • An Optical Sensor Instrumented in Spark Plug for In-situ Fuel Concentration Measurement in an Engine Cylinder by 3.39 mm Infrared Absorption Method,

    Tomita, E, Kawahara, N, Shigenaga, M, Yoshiyama, S, Hamamoto, Y, Kakuho, A, Itoh, T, Dibble, R.W

    11th Int. Symp. on Application of Laser Techniques on Fluid Mechanics   2002年

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  • Transient Temperature Measurement of Unburned Gas in an Engine Cylinder Using Fiber-Optic Heterodyne Interferometry,

    Kawahara, N, Tomita, E, Kamakura, H, Ichimiya, M

    11th Int. Symp. on Application of Laser Techniques on Fluid Mechanics   2002年

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  • Measurement of Transient Temperature of Gas Using Fiber Optic Heterodyne Interferometer

    Kawahara, N, Tomita, E, Kamakura, H

    Proc. of 3rd ASPACC   2001年1月

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    A fiber optical heterodyne interferometry system was developed to obtain high temporal resolution temperature histories of unburned and burned gases non-intrusively. The effective optical path length of the test beam changes with the gas density and corresponding changes of the refractive index. Therefore, the temperature history of the gas can be determined from the pressure and phase shift of the interference signal. The resolution of the temperature measurement is approximately 0.5 K, and is dependent upon both the sampling clock speed of the A/D converter and the length of the test section. A polarization-preserving fiber is used to deliver the test beam to and from the test section, to improve the feasibility of the system as a sensor probe. This optical heterodyne interferometry system may also be used for other applications that require gas density and pressure measurements with a fast response time, or a transient temperature record. Copyright © 2001 Society of Automotive Engineers, Inc.

    DOI: 10.4271/2001-01-1922

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  • ガンタイプバーナにおける噴霧のレーザ計測(噴霧クラスタと群燃焼構造)

    河原伸幸, 池田裕二, 中島 健

    日本機械学会論文集B編   67 ( 655 )   841 - 848   2001年

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    記述言語:日本語  

    A concept of &quot;compound-cluster combustion&quot; is proposed in order to investigate an applicability of group combustion theory to practical spray combustion, in which strong turbulent coherent vortex is formed and influenced spray behavior significantly. This turbulent coherent structure causes inhomogeneous droplet distribution and its population, and causes interphase exchange of properties and combustion under the effects of preferential interactions. In application of group combustion theory to practical spray combustion, these points were taken into account and phase Doppler measurement (PDA) data was analyzed : there are multiple clusters, characterized by their size and followabiliy (Stokes effect) ; clusters of different droplet sizes are produced at the same time in the flow field; the turbulent scale on cluster formation should be considered by the droplet&#039;s inter-arrival time statistics. In this research, PDA measurement with high sampling-rates and high validation- rates was carried out by optimizing the PDA set-up parameters. The integral length scale of each size cluster and the inter-arrival time statistics of the droplets can be obtained, based on the instantaneous droplet velocities as well as, but also Stokes&#039; number, cluster size and inter-arrival time. The size-classified group combustion number is evaluated by the experimental data to demonstrate the applicability of group combustion theory. The interaction between the turbulent coherent vortex and small droplets of less than 30 μm generates essential clusters of the droplets and its combustion can be characterized by group combustion. The size of these clusters corresponds to the integral scale of the turbulent vortices. The effect of turbulent coherent structure on compound- cluster formation is examined and this effect is successfully evaluated by the Stokes effect.

    DOI: 10.1299/kikaib.67.841

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  • 光ヘテロダイン干渉法によるガス温度変化計測

    河原伸幸, 冨田栄二

    光アライアンス   Vol.12, No.12, pp.18-21   2001年

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  • Hydrogen combustion and exhaust emissions ignited with diesel oil in a dual fuel engine

    Eiji Tomita, Nobuyuki Kawahara, Zhenyu Piao, Shogo Fujita, Yoshisuke Hamamoto

    SAE Technical Papers   2001年

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    記述言語:英語  

    Hydrogen is expected to be one of the most prominent fuels in the near future for solving greenhouse problem, protecting environment and saving petroleum. In this study, a dual fuel engine of hydrogen and diesel oil was investigated. Hydrogen was inducted in a intake port with air and diesel oil was injected into the cylinder. The injection timing was changed over extremely wide range. When the injection timing of diesel fuel into the cylinder is advanced, the diesel oil is well mixed with hydrogen-air mixture and the initial combustion becomes mild. NOx emissions decrease because of lean premixed combustion without the region of high temperature of burned gas. When hydrogen is mixed with inlet air, emissions of HC, CO and CO2 decrease without exhausting smoke while brake thermal efficiency is slightly smaller than that in ordinary diesel combustion. In particular, both smoke and NOx are almost zero and HC is low when the injection timing is significantly advanced although the engine operation becomes unstable. Copyright © 2001 Society of Automotive Engineers, Inc.

    DOI: 10.4271/2001-01-3503

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  • Effects of swirl turbulent flow field and inhomogeneous concentration field on combustion of fuel-air mixture in a constant volume vessel

    Kawahara, N, Tomita, E, Nishiyama, A, Yoshiyama, S, Hamamoto, Y

    Proc. of 5th COMODIA 2001   2001年

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  • Combustion Characteristics of Stratified Fuel-Air Mixture with Swirl in a Constant-Volume Vessel

    Nishiyama, A, Tomita, E, Kawahara, N, Hamamoto, Y, Yoshiyama, S

    Proc. of 3rd ASPACC   2001年

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  • Effect of acoustic streaming on the mass transfer from a sublimating sphere

    N Kawahara, AL Yarin, G Brenn, O Kastner, F Durst

    PHYSICS OF FLUIDS   12 ( 4 )   912 - 923   2000年4月

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    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    The effect of the acoustic streaming on the mass transfer from the surface of a sphere positioned in an ultrasonic acoustic levitator is studied both experimentally and theoretically. Acoustic levitation using standing ultrasonic waves is an experimental tool for studying the heat and mass transfer from small solid or liquid samples, because it allows an almost steady positioning of a sample at a fixed location in space. However, the levitator introduces some difficulties. One of the main problems with acoustic levitation is that an acoustic streaming is induced near the sample surface, which affects the heat and mass transfer rates, as characterized by increased Nusselt and Sherwood numbers. The transfer rates are not uniform along the sample surface, and the aim of the present study is to quantify the spatial Sherwood number distribution over the surface of a sphere. The experiments are based on the measurement of the surface shape of a sphere layered with a solid substance as a function of time using a charge-coupled device (CCD) camera with backlighting. The sphere used in this research is a glass sphere layered with a volatile solid substance (naphthalene or camphor). The local mass transfer from the surface both with and without an ultrasonic acoustic field is investigated in order to evaluate the effect of the acoustic streaming. The experimental results are compared with predictions following from the theory outlined [A. L. Yarin, M. Pfaffenlehner, and C. Tropea, J. Fluid Mech. 356, 65 (1998); A. L. Yarin, G. Brenn, O. Kastner, D. Rensink, and C. Tropea, ibid. 399, 151 (1999)] which describes the acoustic field and the resulting acoustic streaming, and the mass transfer at the surface of particles and droplets located in an acoustic levitator. The results are also compared with the experimental data and with the theoretical predictions of Burdukov and Nakoryakov [J. Appl. Mech. Tech. Phys. 6, 51 (1965)], which are valid only in the case of spherical particles much smaller than the sound wavelength. Good agreement between experiment and the theory of Yarin is demonstrated. The time-averaged heat and mass transfer rates over a sphere surface are greatest at the sphere's equator and least at its poles in the experiment as predicted by the theory (the ultrasonic standing wave spans the vertical axis passing through the poles). The measured distribution of the mass transfer rate over the sphere surface also agrees with the theoretical predictions, which shows that in strong acoustic fields sublimation (or evaporation) results from the acoustic streaming. (C) 2000 American Institute of Physics. [S1070-6631(00)02104-8].

    DOI: 10.1063/1.870347

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  • Fuel Concentration Measurement near Spark-Plug in a Spark-Ignition Engine by 3.39m Infrared Laser Absorption Method

    Tomita, E, Kawahara, N, Yoshiyama, S, Hamamoto, Y

    Proc. of 22nd Task Leaders Meeting, Int. Energy Agency Executive Committee on Energy Conservation and Emission Reduction in Combustion   2000年

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  • Transient Temperature Measurement of Unburned Gas Using Optic Heterodyne Interferometry

    Kawahara, N, Tomita, E, Kamakura, H

    10th Int. Symp. on Application of Laser Techniques on Fluid Mechanics   2000年

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  • A Study on Hydrogen Combustion Ignited with Light Oil in a Dual Fuel Engine

    Tomita, E, Kawahara, N, Hamamoto, Y, Zhen-Yu Piao, Fujita, S

    4th JSME-KSME Thermal Engineering Conference   2000年

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  • Flame Propagation of Inhomogeneous Fuel-Air Mixture with Swirl in a Constant-Volume Vessel

    Kawahara, N, Tomita, E, Yoshiyama, S, Nishiyama, A, Hamamoto, Y

    4th JSME-KSME Thermal Engineering Conference   2000年

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  • Measurements of the Combustion Characteristics of Compound Clusters in Pressure-Atomized Spray Flame

    Kawahara, N, Ikeda, Y, Nakajima, T

    37th AIAA Aerospace Sciences Meeting and Exhibit, AIAA Paper No.99-0210   1999年1月

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    © l999 American Institute of Aeronautics &amp; Astronautics. In order to understand the combustion characteristics of droplet clusters consisting of a number of cluster sizes of i.nhomogeneous droplets, measurements of local chemiluminescence (OH, CH arid C,) were taken simultaneously with measurements of the droplets’ size and velocity in a spray flame stabilized by a recirculating flow. The limitations of using Cassegmin optics to measure chemiluminescence in actual spray flames was investigated. The Cassegrain optics developed were able to detect the local chemiluminescences of OK CH and C, in an actual spray flame. The intensity ratio of the time-averaged local chemiluminescences (&amp;/OH) showed the local equivalence ratio of the fuel droplets in the spray flame. These five signals were analyzed statistically and spectrally, and finally combined to produce cross-correlation coefficients. These data can provide inhormation about the combustion characteristics of droplet clusters. The change in the burning mode of droplet clusters, from external group combustion to internal group combustion, was confirmed experimentally.

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  • Effects of different kinds of fuel and fuel equivalence ratio on flame structure of triple flame

    Hiroshi Yamashita, Nobuyuki Kawahara, Nag Jung Choi

    Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B   65   775 - 782   1999年1月

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    In order to clarify the effects of different kinds of fuel and fuel equivalence ratio on flame structure, a numerical simulation of triple flame developed in a co-flowing methane-air or hydrogen-air mixture and air stream was made taking into account the elementary chemical reaction mechanism. The following conclusions were reached: (1)The relation between the apparent burning velocity of the triple flame and the fuel equivalence ratio shows a similar tendency to that of the one-dimensional premixed flame of the corresponding fuel. However, the fuel equivalence ratio at which the apparent burning velocity is the largest is a little larger than that of the one-dimensional premixed flame. The apparent burning velocities are two and three times higher than that of the one-dimensional premixed flame for the methane-air or hydrogen-air mixture. ( 2 )The flame thrusts out forward in the downstream of the boundary between mixture and air stream, and a part of the flow is bent and forks out in this protruding flame so that a triple flame is originated ; this triple flame is composed of fuel rich and lean premixed flame branches and a diffusion flame branch. The change in shape of the convex part, caused by the effect of the one-dimensional premixed flame, is further promoted by the effect of hydrodynamic instability originated in the expansion brought about by heat release. A considerably strong diffusion flame branch exists almost in the center of the two premixed flame branches for the methane-air mixture, while a considerably weak diffusion flame branch approaches the fuel lean premixed flame branch for the hydrogen-air mixture. ( 3 )Near the fuel equivalence ratio at which the burning velocity of the one-dimensional premixed flame is the largest, the effect of the one-dimensional premixed flame becomes large and the fuel rich premixed flame advances and becomes vertical to the flow direction. As a result, the effect of hydrodynamic instability is weakened. Thus, both of these effects demonstrate that the fuel equivalence ratio at which the apparent burning velocity is the largest is a little larger than that of the one-dimensional premixed flame.

    DOI: 10.1299/kikaib.65.775

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  • Size-Classified Droplets Dynamics of Combusting Spray in Oil MW Oil Furnace

    Nobuyuki Kawahara, Yuji Ikeda, Tsuyoshi Nakajima

    Jaurnal of the Japan Society of Mechanical Engineering   65 ( 630 )   790 - 797   1999年1月

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    The purpose of the present research is to investigate the aerodynamic characteristics of evaporating droplet near the burner where flame is hold by the recirculating flow and to characterize droplet aerodynamic response regarding follow or penetration and turbulent interaction with the surrounding air by classifing droplets. Aerodynamic characteristics of combusting spray were measured in a small industrial oil furnace by a phase Doppler anemometer. The size-classified technique was used together with the relative Reynolds number and the recombined two-dimensional size-classified droplet velocity. The results show that the two-dimensional behavior of a spray flame can be represented. The size-classified droplet technique can provide very useful information on droplet aerodynamics and dispersion. The follow/penetration characteristics of spray can be understood very well in consideration of the features of classified droplet in combustion condition. Larger droplets had a large mass and inertia, and thus could penetrate through the recirculation flow region. Consequently larger droplets form large luminous flame. On the other hand, smaller droplets were entrained by the turbulent air flow and played a role of flame-holder. In addition, the interaction between fuel droplets and air flow is a process that significantly affects flame-holding mechanism of spray flames.

    DOI: 10.1299/kikaib.65.790

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  • Development of Light-Collecting Probe with High Spatial Resolution Applicable to Randomly Fluctuating Combustion Fields

    Akamatsu, F, Wakabayashi, T, Tsushima, S, Katsuki, M, Mizutani, Y, Ikeda, Y, Kawahara, N, Nakajima, T

    Measurement Science and Technology   10   1240 - 1246   1999年1月

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    A high-luminosity-light-collection system for highly spatial detection of chemiluminescence of radical species in flames has been developed. The system, multi-colour integrated Cassegrain receiving optics (MICRO) is based upon a Cassegrain-type configuration, which implies that it employs only reflective components (in combination with an optical fibre for light collection). It provides therefore spherical-and chromatic-aberration-free detection, which is of importance for high-spatial-resolution measurements and for the simultaneous monitoring of signals in different wavelength regions from a given spatial volume. The effective light-collection volume has been estimated to be only 1.6 mm × 0.2 mm × 0.2 mm by ray-tracing techniques, which is more than three orders of magnitude smaller than that provided by a corresponding simple single-lens system and comparable to that of laser-based techniques, e.g. Doppler anemometry. The system is also easily aligned since the active probe volume can be visualized by sending in visible light through the system in the reverse direction. In order to demonstrate the performance of the system, OH-radical chemiluminescence in a Bunsen flame was monitored using MICRO and compared with the ion-current signal from a Langmuir probe with a minute sensor tip. A good correlation between the fluctuations in the two signals could be obtained, proving the high spatial and temporal resolution of the MICRO system.

    DOI: 10.1088/0957-0233/10/12/316

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  • Observation of Compound-Cluster Combustion in Pressure-Atomized Spray Flame

    Kawahara, N, Ikeda, Y, Nakajima, T

    Proc. of 2nd ASPACC   1999年

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  • Development of a Multi-Color light collection probe with high spatial resolution (1st Report, Evaluation of spatial resolution by Ray-Tracing Method)

    Takashi Wakabayashi, Fumiteru Akamatsu, Masashi Katsuki, Yukio Mizutani, Yuji Ikeda, Nobuyuki Kawahara, Tsuyoshi Nakajima

    Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B   64   925   1998年1月

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    Spot monitoring of radical chemiluminescence is especially useful for flame diagnostics, if the measuring control volume size can be clearly defined. However, a typical light collection system consisting of a spherical lens and a pinhole suffers from its wide and long control volume, as well as its significant chromatic aberration between UV and visible ranges in simultaneous multi-color measurement. In some cases, researchers were obliged to insert a control-volume limiting device into the flame for observing the local emission intensities of radical chemiluminescence. To resolve these problems, we have developed a light collection probe of Cassegrain type, which consists of a set of concave and convex mirrors combined with an optical fiber cable, and is free from both chromatic and spherical aberrations, which was named Multi-color Integrated Cassegrain Receiving Optics (MICRO). The spatial resolution was analyzed by the ray-tracing method, and the effective control volume size was estimated as 1.6 mm-long and 200 μn diameter, which is as small as that of LDA or PDA.

    DOI: 10.1299/kikaib.64.925

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  • Droplet dispersion and turbulent structure in a pressure-atomized spray flame

    Nobuyuki Kawahara, Yuji Ikeda, Tsuyoshi Nakajima

    35th Aerospace Sciences Meeting and Exhibit   1997年1月

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    © 1997, American Institute of Aeronautics and Astronautics, Inc. Investigation of the relationship between droplet dispersion and turbulent mixing in a pressure-atomized spray flame with a recirculation region was done. Time-resolved information of instantaneous droplet velocities and interarrival-time statistics of the droplet were obtained and examined in order to observe the turbulent mixing and follow/ penetration criteria. In order to observe the detailed structure of spray flames, the size and velocity of droplets instantaneously were measured by phase Doppler anemometer. The group combustion number was calculated by the experimental data in order to elucidate the actual aspects of group combustion. It was found that the turbulent coherent structures were contributed in order to form droplet clusters of small droplets under 30 µm because of its momentum, inertia and followability. The cluster dimensions obtained corresponded with the integral scale of turbulent vortex measured. While, large droplets penetrates strongly due to large momentum and less shear flow information along the spray cone so that group combustion characteristics could not be observed. The interaction and its relation of turbulent scale and group combustion cluster was discussed with measured data for a practical oil burner of 0.1MW.

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  • Fuel droplet dynamics and dispersion of practical twin-fluid atomizer for oil furnace

    Y. Ikeda, N. Tsuchimoto, N. Kawahara, T. Nakajima

    International Journal of Fluid Mechanics Research   24 ( 1-3 )   138 - 148   1997年

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    記述言語:英語   出版者・発行元:Begell House Inc.  

    The purpose of this study is to investigate fuel droplet dispersion and mixture formation in a practical twin-fluid atomizer for a practical oil furnace of 1 MW. In this experiment, droplet size, velocity and dispersion data were measured to show two-dimensional droplet velocity vectors using phase Doppler technique (PDA/PDPA). Fuel droplet dynamics and spray characteristics are discussed by two-dimensional size-classified droplet vector and their slip velocities vector. The spray dynamics is investigated by not only Sauter mean diameter but also each size-classified velocity. The results showed that the size classified technique was suitable and the strong penetration of small droplet near nozzle and the much entrainment flow were yielded at the middle of the jet plane. The injection pressure was varied to show the spray characteristics changes for different conditions.

    DOI: 10.1615/InterJFluidMechRes.v24.i1-3.140

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  • Flame holding in a gun-type oil burner (fluctuation characteristics and concentration variation)

    Yuji Ikeda, Nobuyuki Kawahara, Tsuyoshi Nakajima

    Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B   62   1599 - 1607   1996年1月

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    Three dimensional measurements of velocity and gas flux measurements of O2, CO2 flux near burner of oil furnace were demonstrated to show a flame holding mechanism and fluctuation characteristics. The use of convective flux in flame was not accurate but found to be applicable in whole combustion region in a furnace. Two pairs of recirculating flow region rotated in swirl direction due to the slit flow and its timescale was about 5-10 msec. The timescale of turbulence and CO, CO2 gas variation were compared in order to show the flame holding mechanism in a transparent evaporating region. The comparison results show that the timescale of turbulence and chemical species fluctuation were the same order.

    DOI: 10.1299/kikaib.62.1599

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  • Combusting Flow Simulation in an oil Furnace

    Yuji Ikeda, Nobuyuki Kawahara, Tsuyoshi Nakajima

    Jaurnal of the Japan Society of Mechanical Engineering   62 ( 598 )   2481 - 2489   1996年1月

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    Combusting flow simulations in an oil furnace (0.1 MW) were carried out in order to investigate droplet behavior and the flame-holding mechanism. Measurements made by a phase Doppler anemometer were also examined to elucidate the followability characteristics in recirculation flow. The results show that a droplet under 30 microns can follow the flow but a droplet over 50 microns penetrates. The use of connective flux of O2and CO2both in the flame and the entire furnace was examined and the results demonstrated that it was very useful to show the self-recirculating flow in furnaces.

    DOI: 10.1299/kikaib.62.2481

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  • Flux Measurements of O<sub>2</sub>, CO<sub>2</sub> and No in Oil Furnace

    Yuji Ikeda, Nobuyuki Kawahara, Tsuyoshi Nakajima

    Journal of the Japan Society of Mechanical Engineering   61 ( 581 )   332 - 338   1995年1月

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    The flow velocity measurements and flux measurements of gas species of O2, CO2and NO in an oil furnace were carried out. The velocity profiles in combustion and noncombustion were measured by the developed LDV, and the results show that the reversing flow regions for both cases were located at the same place and their volumes were almost equal. The comparisons of measured concentration and flux obtained using velocity and temperature were performed in spray combustion. The results show that there is little difference in the flame region but a large discrepancy outside of the flame region. The generated gas species in the flame and its convection outside of the flame were discretized, and the application of flux in spray combustion research was found to be very useful and effective. © 1995, The Japan Society of Mechanical Engineers. All rights reserved.

    DOI: 10.1299/kikaib.61.332

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  • Flux measurements of O2, CO2 and NO in an oil furnace

    Yuji Ikeda, Nobuyuki Kawahara, Tsuyoshi Nakajima

    Measurement Science and Technology   6 ( 6 )   826 - 832   1995年

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    記述言語:英語  

    The flow velocity measurements and flux measurements of the gas species O2, CO2 and NO in an oil furnace were carried out. The velocity profiles in combustion and non-combustion were measured by the developed laser Doppler velocimeter, and the results show that the reversing flow regions for both cases were located at the same place and their volumes were almost equal. The comparisons of measured concentration and flux obtained using velocity and temperature were performed in spray combustion. The results show that there is little difference in the flame region but a large discrepancy outside the flame region. The generated gas species in the flame and their convection outside the flame were discretized, and the application of flux in spray combustion research was found to be very useful and effective.

    DOI: 10.1088/0957-0233/6/6/019

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▼全件表示

講演・口頭発表等

  • 赤外吸収法による排気管内未燃焼炭化水素濃度測定

    自動車技術会2005年秋季大会学術講演会,講演番号186,Paper No.20055839,講演前刷集No.19-04, 93, pp.5-8  2205年 

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  • 圧縮膨張機関での二元燃料燃焼におけるエンドガス自着火の可視化

    第55回燃焼シンポジウム  2017年 

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  • 高速度カメラを用いた初期火炎核形成過程の可視化

    第28回内燃機関シンポジウム  2017年 

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  • Novel Noncontact Measurement Method of Combustion Gas Using X-rays

    BIT’s 5th Annual Congress of AnalytiX-2017  2017年 

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  • 火花点火機関におけるエンドガス部での化学反応計算

    日本機械学会中国四国支部第55期総会・講演会  2017年 

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  • 点火プラグ後背流速の局所2次元計測

    可視化情報全国講演会  2017年 

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  • Evaluation of Nozzle Exit Model for Transient Spray in a Multi -Hole DISI Injector

    19th Annual Conference of ILASS-Asia  2017年 

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  • Chemical Kinetics and Computational Fluid-Dynamics Analysis of H2/CO/CO2/CH4 Syngas Combustion and NOx Formation in a Micro-Pilot-Ignited Supercharged Dual Fuel Engine

    13th International Conference on Engine & Vehicles  2017年 

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  • Multidimensional CFD Simulation of Diesel Spray Combustion Using Chemical Kinetics

    The 9th International Conference on Modeling and Diagnostics for Advanced Engine Systems (COMODIA2017)  2017年 

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  • 火花放電挙動と点火プラグ後流の可視化

    第28回内燃機関シンポジウム  2017年 

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  • 水素直噴火花点火機関における水素噴流と燃焼の数値解析

    第28回内燃機関シンポジウム  2017年 

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  • SIBS法による水素エンジンでの点火プラグ近傍プラズマ分光解析

    第28回内燃機関シンポジウム  2017年 

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    第26回微粒化シンポジウム  2017年 

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  • 筒内直接噴射水素エンジンの噴流制御による熱効率の向上とNOx低減効果および燃焼特性に関する研究

    自動車技術会2017秋季学術講演会  2017年 

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  • 赤外吸収法を利用したエンジンシリンダ内残留ガス濃度計測

    第28回内燃機関シンポジウム  2017年 

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  • 水素直噴火花点火機関における火花勇気ブレイクダウン分光法における局所空気過剰率計測 -露光条件が局所空気過剰率計測に与える影響-

    第27回内燃機関シンポジウム  2016年 

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  • Plasma temperature of spark discharge in a spark-ignition engine using a time series of spectra measurements

    18th Int. Symp. on Application of Laser Techniques on Fluid Mechanics  2016年 

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  • 火花点火機関における希薄燃焼時の火花放電・火炎伝播の同時可視化

    自動車技術会2016年春季大会  2016年 

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  • 火花点火機関における点火過程のモデル化

    第54回燃焼シンポジウム  2016年 

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  • 火花点火機関を対象とした火炎伝播の数値解析

    第54回燃焼シンポジウム  2016年 

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  • High-speed visualization of fuel spray impingement in the near-wall region using a DISI injector

    The 31st International Congress on High-Speed Imaging and Photonics  2016年 

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  • Droplet diameter measurement near a nozzle exit of a gasoline DISI injector

    18th Annual Conference on Liquid Atomization and Spray Systems–Asia (ILASS-Asia 2016)  2016年 

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  • Local air-fuel ratio measurement using spark-induced breakdown spectroscopy (SIBS) in a hydrogen DISI engine

    IFAT 2016  2016年 

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  • Temporally and spectrally resolved measurement of spark discharge in a spark ignition engine

    The 4th Laser Ignition Conference 2016  2016年 

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  • ディーゼル噴霧燃焼の数値解析における初期条件の検討

    第25回微粒化シンポジウム  2016年 

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  • DISIエンジンにおける燃料噴霧の壁面衝突挙動(表面粗さが臨界Weber数に与える影響)

    第25回微粒化シンポジウム  2016年 

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  • DISIエンジンにおける燃料噴霧の壁面衝突挙動(ノズル出口モデルおよび壁面衝突挙動の数値計算による検証)

    第25回微粒化シンポジウム  2016年 

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  • 赤外線吸収法を利用したエンジンシリンダ内残留ガス濃度計測(高EGR条件下でのCO²濃度計測)

    第27回内燃機関シンポジウム  2016年 

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  • Combustion Diagnostics Using Time-Series Analysis of Radical Emissions in a Practical Engine

    21st Small Engine Technology Conference (SETC) (Osaka, Japan)  2015年 

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  • 高圧筒内直接噴射水素エンジンの熱効率向上を指向した噴射時期と噴流形状に関する研究

    自動車技術会2015秋季学術講演会  2015年 

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  • 遺伝的アルゴリズムを用いたPRF素反応スキームの最適化-着火遅れに及ぼす素反応スキームの影響 -

    第53回燃焼シンポジウム  2015年 

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  • 軽油着火式ガスエンジンにおけるPREMIER燃焼の可視化

    第53回燃焼シンポジウム  2015年 

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  • ガスパーセル法を用いた水素DISIエンジン内水素噴流挙動の数値シミュレーション

    自動車技術会2015秋季学術講演会  2015年 

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  • 天然ガスエンジンにおけるPREMIER燃焼の可視化

    自動車技術会2015秋季学術講演会  2015年 

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  • Visualization of fuel impingement on the piston top in a DISI engine

    13th International Conference on Liquid Atomization and Spray Systems (ICLASS ) (Tainan, Taiwan)  2015年 

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  • Effects of Bio-gas Contents on SI Combustion for a Co-generation Engine

    SAE 2015 Powertrains, Fuels and Lubricants Meeting (Kyoto Japan)  2015年 

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  • Effect of Hydrogen Concentration on Engine Performance, Exhaust Emissions and Operation Range of PREMIER Combustion in a Dual Fuel Gas Engine using Methane-Hydrogen mixtures

    SAE 2015 Powertrains, Fuels and Lubricants Meeting (Kyoto Japan)  2015年 

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  • DISI用インジェクタにおけるノズル出口モデルの構築

    第24回微粒化シンポジウム  2015年 

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  • 遺伝的アルゴリズムを用いたPRF素反応スキームの最適化(層流燃焼速度に及ぼす素反応スキームの影響)

    第26回内燃機関シンポジウム  2015年 

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  • Time-Series Analysis of Radical Emissions Using a Spark-Plug with Optical Fiber

    35th International Symposiumon Combustion  2014年 

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  • 直接噴射火花点火エンジン用マルチホールインジェクタのノズル出口近傍における粒径および流速の同時計測

    第23回微粒化シンポジウム  2014年 

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  • DISI 機関におけるピストン頂面への燃料衝突およびプール燃焼の可視化

    第23回微粒化シンポジウム  2014年 

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  • Evaluating Effect of Elevated Water Content on Laser-Ignition Characteristics of Premixed Charge of Ethanol-Air

    第52回燃焼シンポジウム  2014年 

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  • 局所燃料~空気予混合気の混合比計測

    日本機械学会研究協力部会 RC255  2014年 

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  • Effect of Hydrogen Concentration on Engine Performance and Operating Range of PREMIER combustion in a Dual Fuel Gas Engine Using Methane-Hydrogen Mixtures

    第52回燃焼シンポジウム  2014年 

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  • エンジンシリンダ内乱流予混合火炎の観察―実機関における時系列ラジカル自発光解析を用いた燃焼診断―

    第25回内燃機関シンポジウム  2014年 

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  • DISI マルチホールインジェクタにおける非定常噴霧の数値解析

    第25回内燃機関シンポジウム  2014年 

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  • 赤外吸収法を用いたスプレーガイド直噴機関における点火プラグ近傍空燃比計測

    自動車技術会2014秋季大会  2014年 

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  • Effect of Split Micro-pilot Fuel Injection on Engine Performance, Exhaust Emissions, Flame Development and Operation Range of PREMIER Combustion in a Dual Fuel Engine using Natural Gas

    35th International Symposiumon Combustion  2014年 

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  • Time-series Spectra Measurements from Initial Flame Kernel in a Spark-Ignition Engine

    17th Internationl Symposium on Applications of Laser Techniques to Fluid Mechanics  2014年 

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  • スプレーガイド直噴機関におけるマイクロ波プラズマのプラズマ形成過程

    自動車技術会2014春季大会  2014年 

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  • Laser Ignition Characteristics of Hydrous Ethanol

    The 2nd Laser Ignition Conference  2014年 

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  • 高圧筒内直接噴射水素エンジンの軸方向成層化による部分負荷運転時における熱効率の向上

    自動車技術会2014秋季大会  2014年 

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  • SIBS法による高圧筒内直接噴射水素エンジンでの点火プラグ近傍局所空気過剰率計測

    自動車技術会2014秋季大会  2014年 

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  • Air-fuel ratio near the spark-plug and combustion characteristics in a direct-Injection hydrogen engine

    34th Task Leaders Meeting, International Energy Agency Implementing Agreement on Energy Conservation and Emissions Reduction in Combustionl  2012年 

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  • Effect of equivalence ratio on combustion characteristics in a hydrogen direct-injection SI engine

    4th International Conference on Sustainable Automotive Technologies (ICSAT2012)  2012年 

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  • Effect of Spark Timing on Combustion Characteristics in a Direct-Injection Hydrogen Engine

    The 8th KSME-JSME Thermal and Fluids Engineering Conference  2012年 

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  • Low Sooting Combustion in a PCCI Diesel Engine with Moderately Early Injection Timing

    The 8th KSME-JSME Thermal and Fluids Engineering Conference  2012年 

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  • エタノール噴霧におけるレーザ着火特性

    第21回微粒化シンポジウム  2012年 

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  • 水素直接噴射機関における火花誘起ブレイクダウン分光法による局所燃料濃度計測

    第50回燃焼シンポジウム  2012年 

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  • Combustion characteristics of biogas in a dual fuel engine ignited with a pilot diesel fuel

    34th Task Leaders Meeting, International Energy Agency Implementing Agreement on Energy Conservation and Emissions Reduction in Combustionl  2012年 

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  • Time-series measurement of CO2 concentration inside an engine cylinder using infrared absorption method

    The 34th International Symposium on Combustion  2012年 

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  • Spectroscopic analysis of premixed mixture ignition in the end-gas region (PREMIER) combustion in a dual-fuel engine

    The 34th International Symposium on Combustion  2012年 

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  • Jet-guided combustion characteristics and local fuel concentration measurements in a hydrogen direct-injection spark-ignition engine

    The 34th International Symposium on Combustion  2012年 

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  • 水素直噴機関におけるプラズマ支援燃焼の着火特性

    第50回燃焼シンポジウム  2012年 

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  • レーザ干渉法を利用した非定常ガス温度計測システムの開発

    熱工学コンファレンス2012  2012年 

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  • 予混合圧縮着火機関筒内現象の数値解析(燃料噴射時期が燃焼に与える影響)

    第23回内燃機関シンポジウム  2012年 

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  • Combustion and Emission Characteristics of a Low Emission and Highly Efficient PCCI Diesel Engine

    Sustainable Research and Innovation Conference 2012 at JKUAT  2012年 

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  • Mixture-formation Process of Ethanol-blended Gasoline in a Spark-ignition Engine

    The 34th International Symposium on Combustion  2012年 

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  • Spectrum Analysis of Chemiluminescence of a Low Sooting PCCI Diesel Engine Operating with Moderately Early Injection Timing

    The 8th International Conference on Modeling and Diagnostics for Advanced Engine Systems (COMODIA2012)  2012年 

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  • Laser-Induced Plasma Generation and Evolution in a Transient Spray

    16th Int. Symp. on Application of Laser Techniques on Fluid Mechanics  2012年 

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  • 圧力振動を伴わない予混合エンドガス部自着火(PREMIER)燃焼の特性

    日本機械学会研究協力部会RC247光応用計測と数値解析による革新的燃焼技術の進展に関する国際協力研究分科会第11回分科会  2012年 

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  • 半導体レーザ吸収法を用いた水蒸気濃度計測(水蒸気吸収スペクトルの圧力・温度依存性)

    日本機械学会中国四国支部第50期総会  2012年 

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  • エンジンシリンダ内ガス流動に及ぼす吸気管形状の影響

    日本機械学会中国四国支部第50期総会  2012年 

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  • 赤外吸収法を利用したエンジンシリンダ内残留ガス(CO2)濃度計測

    岡山大学自然科学研究科プロジェクト CO2循環・削減型社会実現に向けての融合的研究  2010年 

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  • Effect of component of biomass-based gaseous fuels on combustion in a super-charged gas engine with micro-pilot injection

    Thirty-Second Task Leaders Meeting, International Energy Agency Implementing Agreement on Energy Conservation and Emissions Reduction in Combustion, IEA Task Leaders Meeting  2010年 

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  • Fuel Concentration Measurement of Premixed Mixture in a Spark-Ignition Engine Using Spark-Induced Breakdown Spectroscopy

    Kawahara, N., Tomita, E., Ohtsuki, A  2010年 

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  • Residual Gas Concentration Measurement inside a Spark-ignition Engine Using Infrared Laser Absorption Method

    15th Int. Symp. on Application of Laser Techniques on Fluid Mechanics  2010年 

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  • LIBS/SIBSによる燃料濃度計測技術

    第1回プラズマ支援燃焼研究会  2010年 

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  • Visualization of Knocking Combustion in a Hydrogen Spark-Ignition Engine

    18th World Hydrogen Energy Conference 2010  2010年 

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  • 軽油マイクロパイロット着火過給式水素ガスエンジンの燃焼と排気

    自動車技術会2010年春季大会  2010年 

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  • エタノール混合ガソリンエンジンにおける点火プラグ近傍燃料濃度計測

    日本機械学会イノベーションセンター研究協力事業委員会RC238数値解析と計測による燃焼技術の発展に関する国際協力研究分科会  2010年 

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  • Knock Characteristics and Combustion Spectroscopy in a Small Natural Gas Engine Ignited with a Pilot Injection of Gas Oil

    Second International Conference of Energy Engineering (ICEE-2)  2010年 

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  • Knock Characteristics and Combustion Spectroscopy in a Small Natural Gas Engine Ignited with a Pilot Injection of Gas Oil

    Second International Conference of Energy Engineering (ICEE-2)  2010年 

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  • Dual PDAを用いたガソリン噴霧中における非球形液滴の形状計測

    第19回微粒化シンポジウム  2010年 

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  • 非定常噴霧におけるレーザ誘起プラズマによる着火特性

    第19回微粒化シンポジウム  2010年 

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  • マイクロ波プラズマ燃焼エンジンにおける着火過程の観察

    自動車技術会2010年秋季大会  2010年 

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  • Visualization of Auto-Ignition of End Gas Region without Knock in a Spark-Ignition Natural Gas Engine (Invited)

    KONES Powertrain and Transport  2010年 

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  • 赤外吸収法による燃料噴射弁近傍燃料濃度の計測

    自動車技術会ガソリン機関部門委員会  2010年 

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  • Cycle-resolved Residual Gas Concentration Measurement inside a Heavy-duty Diesel Engine using Infrared Laser Absorption

    33rd International Symposium on Combustion  2010年 

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  • 火花誘起ブレイクダウン分光法による燃料~空気混合比計測- 点火プラグセンサの構築と計測精度評価 -

    第48回燃焼シンポジウム  2010年 

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  • マイクロ波プラズマ燃焼エンジンにおける初期火炎核形成過程と火炎伝播特性

    第21回内燃機関シンポジウム  2010年 

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  • 赤外吸収法を利用した点火プラグ実装型センサによる燃料濃度測定(スプレイガイド直噴エンジンへの適用

    第21回内燃機関シンポジウム  2010年 

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  • 赤外吸収法を利用したエンジンシリンダ内残留ガス濃度計測―ディーゼル機関における内部EGR率計測への適用―

    自動車技術会2010年秋季大会  2010年 

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  • レーザ干渉計を用いた流体温度計測

    日本機械学会中国四国支部第47期総会・講演会,講演番号413,pp.119-120  2009年 

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  • ヘテロダイン干渉法を用いたエンジンシリンダ内温度計測(計測精度の検証)

    第20回内燃機関シンポジウム講演論文集,pp.151-156.  2009年 

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  • 火花点火機関におけるノッキング燃焼時のスス生成挙動の可視化

    第20回内燃機関シンポジウム講演論文集,pp.479-484.  2009年 

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  • 高圧雰囲気場におけるレーザ誘起プラズマの高時間・空間分解光学計測

    第20回内燃機関シンポジウム講演論文集,pp.61-66.  2009年 

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  • Microscopic Visualization of Transient Spray from Multi-hole Injector of DISI Engine

    ICLASS2009,Paper Number: 063  2009年 

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  • ガソリンインジェクタにおける液滴の衝突・合体の可視化

    2009年自動車技術会春季大会・学術講演会,学術講演会前刷集No.79-09, pp.15-18.  2009年 

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  • 火花誘起ブレイクダウン分光法を利用した燃料濃度計測(火花放電が分光スペクトルに与える影響)

    2009年自動車技術会春季大会・学術講演会,学術講演会前刷集No.18-09, pp.5-8.  2009年 

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  • Mixture Formation Process in a Spark Ignition Engine with Ethanol Blended Gasoline

    SAE 2009 Powertrains, Fuels and Lubricants Meeting, SAE Paper No. 2009-01-1957  2009年 

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  • Effect of Fuel Injection Parameters on Engine Performance and Emissions of a Supercharged Producer Gas-Diesel Dual Fuel Engine

    SAE 2009 Powertrains, Fuels and Lubricants Meeting, SAE Paper No. 2009-01-1848  2009年 

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  • Effect of EGR on Combustion and Exhaust Emissions in Supercharged Dual-Fuel Natural Gas Engine Ignited with Diesel Fuel

    SAE 2009 Powertrains, Fuels and Lubricants Meeting, SAE Paper No. 2009-01-1832  2009年 

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  • Visualization of Auto-Ignited Kernel and Propagation of Pressure Wave during Knocking Combustion in a Hydrogen Spark-Ignition Engine

    SAE 2009 Powertrains, Fuels and Lubricants Meeting, SAE Paper No. 2009-01-1773  2009年 

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  • DISI用インジェクタノズル出口近傍におけるPDA計測

    第18回微粒化シンポジウム講演論文集,pp.215-220  2009年 

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  • PDA analysis near nozzle region of Transient Spray from Multi-hole Injector of DISI engine

    The 13th Annual Conference on Liquid Atomization and Spray Systems- Asia, pp.48-55.  2009年 

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  • レーザ誘起ブレイクダウン分光法によるエンジンでの空燃比計測

    日本機械学会中国四国支部第47期総会・講演会講演論文集,講演番号808,pp.271-272  2009年 

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  • 軽油着火過給式天然ガスエンジンにおける分光学的燃焼診断

    日本機械学会中国四国支部 第46期総会・講演会,pp.309-310.  2008年 

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  • VI-105 赤外吸収法を利用したエンジンシリンダ内CO2ガス濃度計測 ―ディーゼル燃焼における高負荷時への適用―

    2008年自動車技術会秋季大会・学術講演会,学術講演会前刷集No.114-08, pp.13-16.  2008年 

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  • 軽油着火過給式天然ガスエンジンの燃焼および排気特性に及ぼすEGRの影響

    2008年自動車技術会秋季大会・学術講演会,学術講演会前刷集No.130-08, pp.17-20.  2008年 

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  • 赤外吸収法を利用した点火プラグ実装型センサによる燃料濃度測定 ―ポート噴射型火花点火機関への適用―

    2008年自動車技術会秋季大会・学術講演会,学術講演会前刷集No.89-08, pp.11-14.  2008年 

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  • エタノール混合ガソリンを燃料とした火花点火機関における混合気形成過程

    2008年自動車技術会秋季大会・学術講演会,学術講演会前刷集No.87-08, pp.1-4.  2008年 

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  • DISIインジェクタにおける非定常噴霧の数値解析(TABモデルの適用性について)

    第17回微粒化シンポジウム講演論文集,pp.327-332.  2008年 

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  • 実用ガソリンインジェクタにおける微粒化過程の可視化(液糸分裂,液滴の衝突・合体挙動)

    第17回微粒化シンポジウム講演論文集,pp.321-326.  2008年 

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  • ノッキング燃焼におけるスス生成過程の可視化

    第46回燃焼シンポジウム講演論文集, pp.144-145.  2008年 

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  • レーザ干渉法を利用したエンジンシリンダ内温度計測 - Gladstone-Dale定数の圧力依存性 -

    第46回燃焼シンポジウム講演論文集, pp.142-143.  2008年 

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  • 火花誘起ブレイクダウン分光法を利用した燃料濃度計測

    2008年自動車技術会秋季大会・学術講演会,学術講演会前刷集No.89-08, pp.7-10.  2008年 

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  • 軽油着火バイオマスガスエンジンの燃焼と排気特性

    自動車技術会2008 年春季大会,講演番号404 ,学術講演会前刷集No.83-08, pp.5-8  2008年 

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  • 水素火花点火機関におけるノッキング現象の観察

    2008年自動車技術会春季大会・学術講演会,学術講演会前刷集No.82-08, pp.21-26.  2008年 

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  • 層流予混合火炎のレーザ消火における数値解析

    日本機械学会中国四国支部 第45期総会・講演会,pp.277-278.  2007年 

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  • 火花点火機関におけるノッキング時の自着火過程の観察

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    日本機械学会中国四国支部 第45期総会・講演会,pp.273-274.  2007年 

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    日本機械学会中国四国支部 第45期総会・講演会,pp.271-272.  2007年 

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    日本機械学会中国四国支部 第45期総会・講演会,pp.267-268.  2007年 

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    日本機械学会年次大会,講演論文集vol.3, pp.207-208.  2007年 

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    2007年自動車技術会春季大会・学術講演会,学術講演会前刷集No.12-07, pp.11-16  2007年 

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    2006年自動車技術会春季大会・学術講演会,学術講演会前刷集, Paper No.20065192  2006年 

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    日本機械学会中国四国支部 第44期総会・講演会  2006年 

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    日本機械学会中国四国支部 第44期総会・講演会  2006年 

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    自動車技術会2005年秋季大会学術講演会,講演番号187,Paper No.20055834,講演前刷集 No.19-04, 93, pp.5-8  2005年 

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    第14回微粒化シンポジウム, pp.121-12  2005年 

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    第43回燃焼シンポジウム, pp.236-237  2005年 

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    第43回燃焼シンポジウム, pp.220-221,  2005年 

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    第14回微粒化シンポジウム  2005年 

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    第42回燃焼シンポジウム,pp.499-500  2004年 

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    第42回燃焼シンポジウム,pp.497-498  2004年 

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  • 密閉燃焼室内における噴霧火炎と周囲空気導入

    日本機械学会中国四国支部第42期講演会No.045-1, pp.241-242,(2004.3.6).  2004年 

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    2004年自動車技術会秋季大会・学術講演会,学術講演会前刷集No.107-04,pp.23-26, (2004.10.29).  2004年 

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    2004年自動車技術会春季大会・学術講演会,学術講演会前刷集No.48-04,pp.19-22, (2004.5.21).  2004年 

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    2004年自動車技術会春季大会・学術講演会,学術講演会前刷集No.19-04,pp.5-8, (2004.5.19).  2004年 

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  • In-Situ Fuel Concentration Measurement near Spark Plug by 3.392 m Infrared Absorption Method (Application to Spark Ignition Engine)

    SAE 2003 World Congress  2003年 

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  • 超音波浮揚場における液滴近傍の音響流解析

    第12回微粒化シンポジウム  2003年 

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  • スワールインジェクタのノズル出口における液膜分裂状態の可視化

    第12回微粒化シンポジウム  2003年 

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  • 軽油着火過給天然ガスエンジンにおける燃焼および排気特性

    2003年自動車技術会秋季大会・学術講演会  2003年 

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  • PIVによるスワールインジェクタのノズル近傍噴霧流動解析

    日本機械学会2003年度年次大会  2003年 

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  • ガソリンインジェクタのノズル近傍における噴霧形成過程の可視化

    第31回可視化情報シンポジウム  2003年 

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  • 超音波浮揚における液滴周り音響流れ場の可視化

    第40回日本伝熱シンポジウム  2003年 

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    第41回燃焼シンポジウム  2003年 

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  • エンジンシリンダ内乱流予混合火炎の観察(フレーミングICCDカメラを用いたラジカル自発光計測)

    第41回燃焼シンポジウム  2003年 

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  • 定容容器内単発噴霧燃焼の観察による燃料油燃焼特性試験装置の開発

    第70回(平成15年秋季)マリンエンジニアリング学術講演会  2003年 

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  • 非定常ジメチルエーテル噴霧の挙動に関する研究

    日本機械学会中国四国支部第41期講演会  2003年 

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  • 小型2ストロークエンジンの不整燃焼改善に関する研究

    日本機械学会中国四国支部第41期講演会  2003年 

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  • In-Situ Fuel Concentration Measurement with Optical Spark Plug Sensor by 3.39 m Infrared Laser Absorption Method

    19th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS)  2003年 

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  • Effects of Swirl Flow and Inhomogeneous Concentration Fields on Combustion of Propane-Air Mixture in a Constant-Volume Vessel

    19th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS)  2003年 

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  • Analysis of Two-Stage Heat Release in HCCI Combustion with Dimethyl Ether

    19th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS)  2003年 

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  • Combustion and Exhaust Emissions in a Hydrogen Fueled Engine Ignited with Light Oil

    The 6th ASME-JSME Thermal Engineering Joint Conference  2003年 

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  • Homogeneous Charge Compression Ignition Combustion with Dimethyl Ether - Analysis of Two-Stage Heat Release -

    The 6th ASME-JSME Thermal Engineering Joint Conference  2003年 

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  • ディーゼル噴霧燃焼に及ぼす燃料内エンジンオイル不純物の影響(定容容器による単発噴霧燃焼の可視化)

    第69回(平成15年春季)マリンエンジニアリング学術講演会  2003年 

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  • 定容容器内燃料―空気混合気の燃焼に及ぼす乱流場・不均一濃度場の影響

    日本機械学会中国四国支部第41期講演会  2003年 

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  • Microscopic Observation of Primary Spray Structure of High-Pressure Swirl Injector for Gasoline Direct Injection Engine

    The 9th Int. Conf. on Liquid Atomization and Spray Systems (ICLASS 2003)  2003年 

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  • Homogeneous Charge Compression Ignition Combustion with Dimethyl Ether -Spectrum Analysis of Chemiluminescence-

    SAE International Spring Fuels & Lubricants  2003年 

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  • Transient Temperature Measurement of Unburned Gas in an Engine Cylinder Using Laser Interferometry with a Fiber-Optic Sensor

    SAE International Spring Fuels & Lubricants  2003年 

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  • An Optical Sensor Instrumented in Spark Plug for In-situ Fuel Concentration Measurement in an Engine Cylinder by 3.39 mm Infrared Absorption Method

    11th Int. Symp. on Application of Laser Techniques on Fluid Mechanics  2002年 

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  • レーザ干渉法を利用した小型温度センサによるエンジンシリンダ内未燃ガス温度計測

    第17回内燃機関シンポジウム  2002年 

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  • 赤外吸収法による火花点火機関からのHC排出濃度計測

    日本機械学会2002年年次大会  2002年 

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  • ジメチルエーテルを用いた予混合圧縮着火燃焼(スペクトル計測)

    2002年自動車技術会春季大会・学術講演会  2002年 

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  • Effects of EGR and Early Injection of Diesel Fuel on Combustion Characteristics and Exhaust Emissions in a Methane Dual Fuel Engine.,

    2002 Powertrain and Fluid Systems Conference and Exhibition  2002年 

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  • Transient Temperature Measurement of Unburned Gas in an Engine Cylinder Using Fiber-Optic Heterodyne Interferometry

    11th Int. Symp. on Application of Laser Techniques on Fluid Mechanics  2002年 

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  • 早期噴射およびEGRによる軽油着火水素吸入機関の燃焼・排気特性

    2002年自動車技術会秋季大会・学術講演会  2002年 

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  • 3.392mm赤外吸収法による点火プラグ近傍混合気濃度計測

    2002年自動車技術会秋季大会  2002年 

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  • 赤外吸収法を利用した点火プラグ実装型センサによる燃料濃度測定(実用機関への適用)

    第40回燃焼シンポジウム  2002年 

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  • Flame Propagation and Combustion Characteristics of Stratified Charge Propane-Air Mixture with Swirling Flow in a Constant-Volume Vessel (Poster)

    29th Int. Symp. on Comb.  2002年 

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  • In-Situ Fuel Concentration Measurement near Spark Plug by 3.39 mm Infrared Absorption Method (Development of a Double-Pass Optical Sensor) (Poster),

    29th Int. Symp. on Comb.  2002年 

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  • Fiber-Optic Heterodyne Interferometry Temperature Measurement of Unburned Gas in a HCCI Engine Fueled with DME (Poster),

    29th Int. Symp. on Comb.,  2002年 

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  • ジメチルエーテルを用いた予混合圧縮着火燃焼(熱発生率と化学発光履歴との関係)

    第17回内燃機関シンポジウム  2002年 

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  • 二元燃料ディーゼル機関における早期噴射の燃焼および排気特性

    日本機械学会中国四国支部第40期講演会  2002年 

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  • 赤外吸収法による火花点火機関排気管内炭化水素濃度の測定

    日本機械学会中国四国支部第40期講演会  2002年 

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  • ジメチルエーテルを用いた予混合圧縮着火燃焼におけるガス温度計測

    第40回燃焼シンポジウム  2002年 

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  • 舶用燃料油の燃焼特性とピストン摺動部スカッフィングとの関係

    第68回(平成14年秋季)マリンエンジニアリング学術講演会  2002年 

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  • 赤外吸収法を利用した点火プラグ実装型センサによる燃料濃度測定

    第17回内燃機関シンポジウム  2002年 

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  • 光ファイバを用いた光ヘテロダイン干渉法による未燃ガス温度変化計測

    第49回応用物理学関係連合講演会  2002年 

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  • 赤外吸収法による火花点火機関排気管内炭化水素濃度の測定

    日本機械学会中国四国支部第40期講演会  2002年 

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  • 二元燃料ディーゼル機関における早期噴射の燃焼および排気特性

    日本機械学会中国四国支部第40期講演会  2002年 

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  • 光ファイバを用いた光ヘテロダイン干渉法による未燃ガス温度変化計測

    第49回応用物理学関係連合講演会  2002年 

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  • 二平行円板間における予混合火炎の消炎過程の温度分布計測

    日本機械学会中国四国支部第39期講演会  2001年 

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  • 3.39mmにおける炭化水素系燃料の吸光係数に及ぼす圧力・温度の影響

    日本機械学会中国四国支部第39期講演会  2001年 

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  • 加圧雰囲気下における非定常燃料噴霧の挙動

    日本機械学会中国四国支部第39期講演会  2001年 

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  • Measurement of Transient Temperature of Gas Using Fiber Optic Heterodyne Interferometer

    Third Asia-Pacific Conference on Combustion (ASPACC2001)  2001年 

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  • 光ヘテロダイン干渉法によるガス温度変化計測

    第26回光学シンポジウム  2001年 

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  • Transient Temperature Measurement of Gas Using Fiber Optic Heterodyne Interferometry

    SAE International Spring Fuels & Lubricants  2001年 

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  • Hydrogen Combustion and Exhaust Emissions Ignited with Diesel Oil in a Dual Fuel Engine

    2001 Fall SAE Fuels and Lubricants Meeting and Exhibition  2001年 

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  • Combustion Characteristics of Stratified Fuel-Air Mixture with Swirl in a Constant-Volume Vessel

    Third Asia-Pacific Conference on Combustion (ASPACC2001)  2001年 

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  • ヘテロダイン干渉法によるエンジンシリンダ内未燃焼混合気温度の計測

    2001年度熱工学講演会  2001年 

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  • Transient Temperature Measurement of Unburned Gas in a Spark-ignition Engine Using Fiber-Optic Heterodyne Interferometry

    Busan Engine International Symposium 2001  2001年 

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  • 水素予混合軽油着火ディーゼル機関の燃焼および排気特性

    日本機械学会2001年年次大会  2001年 

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  • 光ヘテロダイン干渉法によるエンジンシリンダ内未燃ガス温度計測

    日本機械学会2001年年次大会  2001年 

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  • Effects of swirl turbulent flow field and inhomogeneous concentration field on combustion of fuel-air mixture in a constant volume vessel

    Fifth International Symposium on Diagnostics and Modeling of Combustion in Internal Combustion Engines (COMODIA2001)  2001年 

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  • Combustion of Stratified Charge Propane-Air Mixture with Swirling Flow in a Constant-Volume Vessel

    Busan Engine International Symposium 2001  2001年 

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  • ジメチルエーテルを用いた予混合圧縮着火燃焼(燃焼の可視化)

    第39回燃焼シンポジウム  2001年 

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  • 定容容器内旋回乱流場中における不均一予混合気の燃焼特性

    第39回燃焼シンポジウム  2001年 

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  • 定容容器内一次元層状燃料濃度場における火炎伝播と消炎の観察

    第38回燃焼シンポジウム  2000年 

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  • 光ヘテロダイン干渉法によるガス温度の時系列計測

    第38回燃焼シンポジウム  2000年 

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  • 定積容器内旋回乱流場における不均一濃度混合気の燃焼に及ぼす影響

    第38回燃焼シンポジウム  2000年 

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  • 定容容器内一次元層状燃料濃度場を伝播する火炎の観察

    日本機械学会徳島地方講演会  2000年 

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  • 小型センサを使用した3.39μm赤外吸収法による燃焼室内燃料濃度変化の計測

    日本機械学会中国四国支部第38期講演会  2000年 

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  • 光ファイバを用いたヘテロダイン干渉法によるガス温度変化計測

    第16回内燃機関シンポジウム  2000年 

     詳細を見る

  • 定積容器内燃料-空気混合気の燃焼に及ぼす旋回乱流場及び不均一濃度場の影響

    第16回内燃機関シンポジウム  2000年 

     詳細を見る

  • Fuel Concentration Measurement near Spark-Plug in a Spark-Ignition Engine by 3.39mm Infrared Laser Absorption Method

    22nd Task Leaders Meeting, Int. Energy Agency Executive Committee on Energy Conservation and Emission Reduction in Combustion  2000年 

     詳細を見る

  • Transient Temperature Measurement of Unburned Gas Using Optic Heterodyne Interferometry

    10th International Symposium on Application of Laser Technique to Fluid Mechanics  2000年 

     詳細を見る

  • 加圧雰囲気下における非定常燃料噴霧の光学的計測

    日本機械学会徳島地方講演会  2000年 

     詳細を見る

  • A Study on Hydrogen Combustion Ignited with Light Oil in a Dual Fuel Engine

    4th JSME-KSME Joint Thermal Engineering Conference  2000年 

     詳細を見る

  • Flame Propagation of Inhomogeneous Fuel-Air Mixture with Swirl in a Constant-Volume Vessel

    4th JSME-KSME Joint Thermal Engineering Conference  2000年 

     詳細を見る

  • 3.392μm赤外吸収法を用いたエンジンシリンダ内点火栓近傍炭化水素系燃料濃度の計測

    第16回内燃機関シンポジウム  2000年 

     詳細を見る

  • 二元燃料予混合圧縮着火ディーゼル機関における排気特性

    日本機械学会中国四国支部第38期講演会  2000年 

     詳細を見る

  • 局所自発光計測による噴霧群燃焼構造の観察

    第8回微粒化シンポジウム  1999年 

     詳細を見る

  • ガンタイプバーナにおける噴霧群燃焼挙動の観察

    第37回燃焼シンポジウム  1999年 

     詳細を見る

  • 定容容器内旋回乱流場における不均一濃度混合気の燃焼に関する研究

    第37回燃焼シンポジウム  1999年 

     詳細を見る

  • Observation of Compound-Cluster Combustion in Pressure-Atomized Spray Flame

    Third Asia-Pacific Conference on Combustion (ASPACC)  1999年 

     詳細を見る

▼全件表示

産業財産権

  • 点火プラグ

    飯田 訓正, 横森 剛, 店橋 護, 河原 伸幸

     詳細を見る

    出願人:学校法人慶應義塾, 国立大学法人 岡山大学, 国立大学法人東京工業大学

    出願番号:特願2018-023533  出願日:2018年2月13日

    公開番号:特開2019-140005  公開日:2019年8月22日

    J-GLOBAL

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  • 内燃機関のガス濃度計測装置およびセンサプラグ

    大脇 清人, 横山 稔, 森本 巌, 冨田 栄二, 河原 伸幸

     詳細を見る

    出願人:川崎重工業株式会社

    出願番号:特願2009-241682  出願日:2009年10月20日

    公開番号:特開2011-089803  公開日:2011年5月6日

    J-GLOBAL

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  • ガス濃度検出装置

    冨田 栄二, 河原 伸幸

     詳細を見る

    出願人:国立大学法人 岡山大学

    出願番号:特願2007-210560  出願日:2007年8月11日

    公開番号:特開2009-042192  公開日:2009年2月26日

    J-GLOBAL

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  • 温度センサ

    冨田 栄二, 河原 伸幸

     詳細を見る

    出願人:国立大学法人 岡山大学

    出願番号:JP2007052783  出願日:2007年2月15日

    公開番号:WO2007-094435  公開日:2007年8月23日

    J-GLOBAL

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  • 温度センサ

    冨田 栄二, 河原 伸幸

     詳細を見る

    出願人:国立大学法人 岡山大学

    出願番号:特願2008-500553  出願日:2007年2月15日

    特許番号/登録番号:特許第4257438号  発行日:2009年2月13日

    特許第4257438号

    J-GLOBAL

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  • 熱機関またはプラズマ装置に用いる点火または放電プラグ、及び、光計測装置

    河原 伸幸, 池田 裕二

     詳細を見る

    出願人:河原 伸幸

    出願番号:特願2005-112908  出願日:2005年4月8日

    公開番号:特開2006-292524  公開日:2006年10月26日

    J-GLOBAL

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  • 熱機関またはプラズマ装置に用いる点火または放電プラグ,及び,光計測装置

    河原 伸幸, 池田 裕二

     詳細を見る

    出願人:イマジニアリング株式会社, 河原 伸幸

    出願番号:特願2005-112908  出願日:2005年4月8日

    公開番号:特開2006-292524  公開日:2006年10月26日

    特許番号/登録番号:特許第4264480号  発行日:2009年2月27日

    特許第4264480号

    J-GLOBAL

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  • 光学素子、光学系、受光器及び光計測装置

    池田 裕二, 河原 伸幸

     詳細を見る

    出願人:イマジニアリング株式会社

    出願番号:特願2004-223419  出願日:2004年7月30日

    公開番号:特開2006-039481  公開日:2006年2月9日

    J-GLOBAL

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  • 光学素子

    池田 裕二, 河原 伸幸

     詳細を見る

    出願人:イマジニアリング株式会社

    出願番号:特願2004-223419  出願日:2004年7月30日

    公開番号:特開2006-039481  公開日:2006年2月9日

    特許番号/登録番号:特許第4665211号  発行日:2011年1月21日

    J-GLOBAL

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  • 内燃機関のガス濃度検出装置

    長島 慶一, 石川 直宏, 亀井 一浩, 藤井 徳明, 冨田 栄二, 河原 伸幸

     詳細を見る

    出願人:本田技研工業株式会社, 国立大学法人 岡山大学

    出願番号:特願2004-040564  出願日:2004年2月17日

    公開番号:特開2005-233694  公開日:2005年9月2日

    特許番号/登録番号:特許第4493075号  発行日:2010年4月16日

    特願2004-040564

    J-GLOBAL

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  • 内燃機関のガス濃度検出装置

    長島 慶一, 石川 直宏, 亀井 一浩, 藤井 徳明, 冨田 栄二, 河原 伸幸

     詳細を見る

    出願人:本田技研工業株式会社, 国立大学法人 岡山大学

    出願番号:特願2004-040564  出願日:2004年2月17日

    公開番号:特開2005-233694  公開日:2005年9月2日

    J-GLOBAL

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  • 温度計測装置

    冨田 栄二, 河原 伸幸, 土田 直樹

     詳細を見る

    出願人:国立大学法人 岡山大学

    出願番号:特願2002-293757  出願日:2002年10月7日

    公開番号:特開2004-125741  公開日:2004年4月22日

    特許番号/登録番号:特許第4214191号  発行日:2008年11月14日

    4214191

    J-GLOBAL

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  • 温度センサ

    冨田 栄二, 河原 伸幸, 土田 直樹

     詳細を見る

    出願人:岡山大学長, ヤマハ発動機株式会社

    出願番号:特願2002-293756  出願日:2002年10月7日

    公開番号:特開2004-125740  公開日:2004年4月22日

    J-GLOBAL

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  • 温度計測装置,信号処理装置および信号処理プログラム

    冨田 栄二, 河原 伸幸, 土田 直樹

     詳細を見る

    出願人:岡山大学長, ヤマハ発動機株式会社

    出願番号:特願2002-293757  出願日:2002年10月7日

    公開番号:特開2004-125741  公開日:2004年4月22日

    特願2002-293757

    J-GLOBAL

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  • 温度センサ

    冨田 栄二, 河原 伸幸, 土田 直樹

     詳細を見る

    出願人:国立大学法人 岡山大学

    出願番号:特願2002-293756  出願日:2002年10月7日

    公開番号:特開2004-125740  公開日:2004年4月22日

    特許番号/登録番号:特許第4214190号  発行日:2008年11月14日

    J-GLOBAL

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  • ヘテロダイン干渉法による気体温度測定方法およびその装置

    冨田 栄二, 河原 伸幸

     詳細を見る

    出願人:独立行政法人科学技術振興機構

    出願番号:特願2000-219968  出願日:2000年7月21日

    公開番号:特開2002-039870  公開日:2002年2月6日

    特許番号/登録番号:特許第3871860号  発行日:2006年10月27日

    特許第3871860号

    J-GLOBAL

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  • ヘテロダイン干渉法による気体温度測定方法およびその装置

    冨田 栄二, 河原 伸幸

     詳細を見る

    出願人:科学技術振興事業団

    出願番号:特願2000-219968  出願日:2000年7月21日

    公開番号:特開2002-039870  公開日:2002年2月6日

    J-GLOBAL

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▼全件表示

受賞

  • JSAEフェローエンジニア

    2017年  

     詳細を見る

    受賞国:日本国

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  • Best Presented Paper

    2010年  

     詳細を見る

  • 自動車技術会 フェロー

    2009年  

     詳細を見る

    受賞国:日本国

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  • 2009 SAE Excellence in Oral Presentation Award

    2009年  

     詳細を見る

  • 2008 堀場雅夫賞 特別賞

    2008年  

     詳細を見る

    受賞国:日本国

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  • 第20回内山勇三科学技術賞

    2008年  

     詳細を見る

    受賞国:日本国

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  • ベストプレゼンテーション賞

    2008年  

     詳細を見る

    受賞国:日本国

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  • 2008 Best International Paper Award

    2008年  

     詳細を見る

    受賞国:日本国

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  • 優秀講演発表賞

    2007年  

     詳細を見る

    受賞国:日本国

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  • 奨励賞

    2007年  

     詳細を見る

    受賞国:日本国

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  • 2007 Best Paper Award

    2007年  

     詳細を見る

    受賞国:日本国

    researchmap

  • 団体(学会)名:2003 JSAE/SAE International Spring Fuels & Lubricants Meeting, Oral Presentation Award 題目:Transient Temperature Measurement of Unburned Gas in an Engine Cylinder Using Laser Interferometry with a Fiber-Optic Sensor

    2003年  

     詳細を見る

  • 2003 JSAE/SAE International Spring Fuels & Lubricants Meeting Oral Presentation Award Title: Transient Temperature Measurement of Unburned Gas in an Engine Cylinder Using Laser Interferometry with a Fiber-Optic Sensor

    2003年  

     詳細を見る

  • 2003 JSAE/SAE International Spring Fuels & Lubricants Meeting Oral Presentation Award Title: Transient Temperature Measurement of Unburned Gas in an Engine Cylinder Using Laser Interferometry with a Fiber-Optic Sensor

    2003年  

     詳細を見る

  • 団体(学会)名:第12回(2002年春季)応用物理学会講演奨励賞 題目:光ファイバを用いた光ヘテロダイン干渉法による未燃ガス温度変化計測

    2002年  

     詳細を見る

▼全件表示

 

担当授業科目

  • エネルギー工学 (2021年度) 第1学期  - 月1,月2

  • レーザ応用計測学 (2021年度) 後期  - その他

  • 動力熱工学演習 (2021年度) 通年  - その他

  • 機械システム工学演習1 (2021年度) 前期  - その他

  • 機械システム工学演習2 (2021年度) 後期  - その他

  • 機械システム系入門 (2021年度) 第1学期  - 金1~2

  • 機械システム系概論 (2021年度) 特別  - その他

  • 機械システム系概論 (2021年度) 特別  - その他

  • 機械工学英語1 (2021年度) 第3学期  - 金1,金2

  • 機械工学英語2 (2021年度) 第4学期  - 金1,金2

  • 熱エネルギー変換工学 (2021年度) 後期  - 木1,木2

  • 熱力学Ⅱ (2021年度) 第4学期  - 月1,月2,木3,木4

  • 熱力学Ⅱ (2021年度) 第4学期  - 月1,月2,木3,木4

  • 熱力学I (2021年度) 第2学期  - 月5,月6,水1,水2

  • 熱力学I (2021年度) 第2学期  - 月5,月6,水1,水2

  • エネルギー工学 (2020年度) 第1学期  - 月1,月2

  • レーザ応用計測学 (2020年度) 後期  - その他

  • 内燃機関 (2020年度) 第1学期  - 月1,月2

  • 動力熱工学演習 (2020年度) 通年  - その他

  • 機械システム工学概論 (2020年度) 前期  - 金1,金2

  • 機械システム工学演習1 (2020年度) 前期  - その他

  • 機械システム工学演習2 (2020年度) 後期  - その他

  • 機械工学英語 (2020年度) 3・4学期  - 金1,金2

  • 機械工学英語1 (2020年度) 第3学期  - 金1,金2

  • 機械工学英語2 (2020年度) 第4学期  - 金1,金2

  • 熱エネルギー変換工学 (2020年度) 前期  - 水3,水4

  • 熱力学Ⅱ (2020年度) 第4学期  - 月1,月2,木3,木4

  • 熱力学Ⅱ (2020年度) 第4学期  - 月1,月2,木3,木4

  • 熱力学I (2020年度) 第2学期  - 月5,月6,水1,水2

  • 熱力学I (2020年度) 第2学期  - 月5,月6,水1,水2

▼全件表示