研究者詳細 - 河原　伸幸

MISC - 河原　伸幸

分割表示 242 件中 21 - 40 件目／全件表示 >>

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

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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1003 レーザ干渉法を用いた非定常ガス温度計測(燃焼・エンジンシステムI)

西村友孝, 冨田栄二, 河原伸幸

講演論文集 2015 ( 53 ) "1003 - 1"-"1003-2" 2015年2月

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

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

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

ガソリン火花点火エンジンにおける火花放電挙動

河原伸幸

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

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

河原伸幸, 冨田栄二, 外村圭司

微粒化シンポジウム講演論文集 23 179 - 184 2014年12月

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

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

Laser Ignition Characteristics of Hydrous Ethanol

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

The 2nd Laser Ignition Conference 1 - 4 2014年

DISI用インジェクタ近傍における非定常噴霧の微粒化特性

河原伸幸, 冨田栄二, 長谷川僚

微粒化シンポジウム講演論文集 22 393 - 398 2013年12月

F071002 点火プラグ近傍燃料/CO_2濃度の同時計測(【F07100】エンジン開発に関わる最新計測・CAE技術,エンジンシステム部門企画,先端技術フォーラム)

河原伸幸

年次大会 : Mechanical Engineering Congress, Japan 2013 "F071002 - 1"-"F071002-5" 2013年9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, simultaneous measurements of hydrocarbon fuel and carbon dioxide (CO_2) concentrations around a spark plug in the homogeneous-charge spark-ignition and the direct-injection spark-ignition engine by a spark plug sensor using infrared absorption technique were carried out. The new simultaneous measuring system including four optical fibers in an M14 spark plug was developed. It was possible that the simultaneous measurement of CO_2 and fuel concentrations in the homogeneous-charge spark-ignition combustion with methane-air or propane-air mixture. Behavior of initial flame kernel around the spark plug can be understood using hydrocarbon fuel and CO_2 concentrations around a spark plug.

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1406 半導体レーザを用いた水蒸気モル吸光係数の圧力・温度依存性

河原伸幸, 冨田栄二, 家村徳彬

講演論文集 2013 ( 51 ) "1406 - 1"-"1406-2" 2013年2月

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

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

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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軽油着火式二元燃料ガスエンジンにおける筒内燃焼の数値解析-Syngas化学反応機構のバイオガス燃焼への適用-

河副瑠惟, 河原伸幸, 冨田栄二, 坪井和也, 脇坂知行, 近藤守男

内燃機関シンポジウム講演論文集(CD-ROM) 24th 2013年

エタノール噴霧におけるレーザ着火特性

河原伸幸, 冨田栄二, 谷口陽輔

微粒化シンポジウム講演論文集 = Symposium (ILASS-Japan) on Atomization 21 205 - 210 2012年12月

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

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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E134 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(OS-18: 熱・物質移動の計測および現象解析(3))

二宮仁, 冨田栄二, 河原伸幸

熱工学コンファレンス講演論文集 2012 155 - 156 2012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

Laser interferometry system was developed to measure unsteady gas temperature. A 16-element photo-diode array was used as the system to detect moving direction of interference fringe more sensitively. Laser interferometry has advantage of nonintrusiveness and high-response. These advantages can improve weak point of general method such as thermistor and thermocouple. In this study, unsteady air temperature was measured by using developed system. Compared with K-type thermocouple of which wire diameter is 0.014mm, this system showed a good response. Because of high response, this system is expected to measure unsteady gas temperature in industrial field.

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MISC - 河原 伸幸

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MISC - 河原　伸幸