研究者詳細 - 河原　伸幸

MISC - 河原　伸幸

分割表示 242 件中 101 - 120 件目／全件表示 >>

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

© 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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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

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

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

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

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

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

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

Web of Science

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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

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

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

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

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

Kawahara, N

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

PFIインジェクタにおける液柱分裂過程の可視化

河原伸幸

第19回内燃機関シンポジウム講演論文集, 2007-1 2007年

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焼濃度測定 (ロータリエンジンへの適用)

河原伸幸

第19回内燃機関シンポジウム講演論文集, 2007 2007年

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

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

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

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

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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E213 レーザ干渉法を利用した流体温度計測センサ : 水の温度計測(計測1)

冨田栄二, 河原伸幸, 戸田泰治

熱工学コンファレンス講演論文集 2006 349 - 350 2006年11月

記述言語：日本語出版者・発行元：一般社団法人日本機械学会

In this study, a new sensor is proposed to determine water temperature. This sensor 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 equal or closely arranged paths ; therefore, the effect of mechanical vibration on the two test beams is expected to be very small. This sensor was installed on a side wall of a vessel. The temperature near the sensor was also measured with a thermocouple as a reference. The response of the thermocouple was enough to follow the change in water temperature because the speed of temperature is very slow. This paper focuses on the confirmation and evaluation of this system of temperature measurement. The temperature measured with this system agreed well with that measured with a thermocouple. It was confirmed that this sensor system is useful for detecting changes in water temperature.

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バイオマスガスによるマイクロパイロット着火ガスエンジンの性能特性

深谷信彦, 冨田栄二, 河原伸幸, 丸山慶土, 薦田哲男

研究発表会講演論文集 / エネルギー・資源学会 [編] 25 281 - 282 2006年6月

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