研究者詳細 - 河原　伸幸

MISC - 河原　伸幸

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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

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

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

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

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

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

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

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

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

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

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

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 ( 6 ) 138 - 138 2003年

記述言語：英語出版者・発行元：日本機械学会

It is necessary to increase thermal efficiency and reduce exhaust emission for internal combustion engines. Alternative fuels that are not made of petroleum are also one of the important factors. 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 operated with hydrogen and light oil was investigated. The configuration of the diesel engine was not changed except changing the injection timing over very wide range by setting an injection pump synchronized with the engine revolution. Hydrogen was supplied in an intake port with air and light oil was injected into the cylinder. The rate of heat release was determined from the pressure in the cylinder. Here, the concept of HCCI combustion was applied to this engine. When the injection timing of the light oil into the cylinder was advanced to 40 or 50 degrees before the compression top dead center, the light oil was well mixed with hydrogen-air mixture and the combustion became mild. As shown in Fig. A, NOx emissions decreased because of lean premixed combustion without the region of high temperature of burned gas. When hydrogen was mixed with inlet air, emissions of HC, CO and CO_2 decreased Without exhausting smoke while indicated thermal efficiency was slightly smaller than that in ordinary diesel combustion. In particular, both smoke and NOx were almost zero and HC was low when the injection timing is significantly advanced. Moreover, the effects of hydrogen ratio and spray angle on exhaust emissions and engine performance were investigated. If the operating conditions in early injection are chosen appropriately, it is considered that low NOx, HC, CO and CO_2,and zero smoke, can be achieved.[figure]

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TED-AJ03-397 HOMOGENEOUS CHARGE COMPRESSION IGNITION COMBUSTION WITH DIMETHYL ETHER : ANALYSIS OF TWO-STAGE HEAT RELEASE :

Kawahara Nobuyuki, Tomita Eiji, Kagajyo Hisashi

Proceedings of the ... ASME/JSME Thermal Engineering Joint Conference 2003 ( 6 ) 143 - 143 2003年

記述言語：英語出版者・発行元：日本機械学会

Although homogeneous charge compression ignition (HCCI) engines are expected to have both higher thermal efficiency and lower nitrogen oxide (NOx) emissions, they still have problems with high hydrocarbon (HC) and carbon monoxide (CO) production, high rates of heat release, and difficulty in controlling auto-ignition. In order to control auto-ignition in HCCI engines, the reaction mechanism of auto-ignition must be understood. Dimethyl ether (DME), a promising alternative fuel that is suitable for compression ignition engines, shows very strong low-temperature kinetic reactions in HCCI. HCCI combustion shows a peculiar two-stage heat release. The first stage of the heat release curve is associated with low-temperature kinetic reactions, and the time delay between the first and main heat release is attributed to the negative temperature coefficient regime. A study of HCCI fueled with DME may provide useful information on the low-temperature kinetic reactions in HCCI operation. This study investigated the auto-ignition characteristics of an HCCI engine fueled with DME using a single[figure] 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 was examined using instantaneous flame images obtained from a high-speed video. The influences of equivalence ratio and intake temperature on the characteristics of auto-ignition in the HCCI engine were investigated. Spectrum analyses of chemiluminescence using spectroscopy were carried out to investigate the two-stage heat release. Three main conclusions were drawn from this study. (1) The hot-flame reaction progresses homogeneously. DME combustion was found to be non-luminous. (2) With increasing intake temperature and equivalence ratio, varying heat release was observed. Three-stage heat release was also observed. (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.[figure]

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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

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

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

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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504 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

冨田栄二, 河原伸幸, 山口良一, 朴振宇

講演論文集 2002 ( 40 ) 153 - 154 2002年2月

503 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

冨田栄二, 河原伸幸, 中溝大和

講演論文集 2002 ( 40 ) 151 - 152 2002年2月

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

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

Web of Science

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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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