研究者詳細 - 小橋　好充

Mechanism of thermal efficiency improvement in twin shaped semi-premixed diesel combustion 査読

その他リンク： http://journals.sagepub.com/doi/full-xml/10.1177/14680874221075104

Fuel Reformation by Piston Compression of Rich Air-fuel Mixture 査読

Gen Shibata, Go Asai, Shuntaro Ishiguro, Yusuke Watanabe, Yoshimitsu Kobashi, Hideyuki Ogawa

International Journal of Engine Research first published online 2021年9月

ディーゼル燃焼のサイズ依存性を考慮した燃焼改善法の検討招待査読

小橋好充, 新山紘史, 柴田元, 小川英之

マリンエンジニアリング 56 ( 4 ) 592 - 599 2021年7月

Kazuki Inaba, Yanhe Zhang, Yoshimitsu Kobashi, Gen Shibata, Hideyuki Ogawa

International Journal of Engine Research 146808742110264 - 146808742110264 2021年6月

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

Improvements of the thermal efficiency in twin shaped semi-premixed diesel combustion mode with premixed combustion in the primary stage and spray diffusive combustion in the secondary stage with multi-stage fuel injection were investigated with experiments and 3D-CFD analysis. For a better understanding of the advantages of this combustion mode, the results were compared with conventional diesel combustion modes, mainly consisting of diffusive combustion. The semi-premixed mode has a higher thermal efficiency than the conventional mode at both the low and medium load conditions examined here. The heat release in the semi-premixed mode is more concentrated at the top dead center, resulting in a significant reduction in the exhaust loss. The increase in the cooling loss is suppressed to a level similar to the conventional mode. In the conventional mode the rate of heat release becomes more rapid and the combustion noise increases with advances in the combustion phase as the premixed combustion with pilot and pre injections and the diffusive combustion with the main combustion occurs simultaneously. In the semi-premixed mode, the premixed combustion with pilot and primary injections and the diffusive combustion with the secondary injection occurs separately in different phases, maintaining a gentler heat release with advances in the combustion phase. The mechanism of the cooling loss suppression with the semi-premixed mode at low load was investigated with 3D-CFD. In the semi-premixed mode, there is a reduction in the gas flow and quantity of the combustion gas near the piston wall due to the suppression of spray penetration and splitting of the injection, resulting in a smaller heat flux.

DOI： 10.1177/14680874211026429

Fuel adhesion and oil splash on oil-wet cylinder walls with post diesel fuel injections 査読

その他リンク： http://journals.sagepub.com/doi/full-xml/10.1177/14680874211026429

Optimization of Gasoline Compression Ignition Combustion with Ozone Addition and Two-stage Direct-injection at Middle Loads 査読

Yoshimitsu Kobashi, Tu Dan Dan Da, Ryuya Inagaki, Gen Shibata, Hideyuki Ogawa

International Journal of Engine Research 1 - 11 2021年1月

EGR gas composition effects on ignition delays in diesel combustion 査読

Yoshimitsu Kobashi, Masaki Todokoro, Gen Shibata, Hideyuki Ogawa, Toshihiro Mori, Daichi Imai

Fuel 281 118730 - 118730 2020年12月

Mechanism of Thermal Efficiency Improvement in Twin Shaped Semi-Premixed Diesel Combustion 査読

Kazuki Inaba, Yanhe Zhang, Yoshimitsu Kobashi, Gen Shibata, Hideyuki Ogawa

THIESEL 2020 Conference on Thermo- and Fluid Dynamic Processes in Direct Injection Engines 220 - 232 2020年9月

Kinetic Modeling of Steady-state NH3-SCR over a Monolithic Cu-CHA 査読

Wataru Eijima,, Gen Shibata, Naoki Shibayama, Yoshimitsu Kobashi, Hideyuki Ogawa, Ken-ichi Shimizu

Catalysis Today 352 237 - 242 2020年8月

Gen Shibata, Shogo Nishiuchi, Shuntaro Takai, Yoshimitsu Kobashi, Hiroki Kanbe, Eriko Matsumura

International Journal of Engine Research 146808742091414 - 146808742091414 2020年5月

Optimization of combustion noise and thermal efficiency in diesel engines over a wide speed and load operational range 査読

Gen Shibata, Kohei Yamamoto, Mikito Saito, Yuto Inoue, Yasumasa Amanuma, Yoshimitsu Kobashi

International Journal of Engine Research 21 ( 4 ) 698 - 712 2020年4月

掲載種別：研究論文（学術雑誌）出版者・発行元：SAGE Publications

Pre-mixed diesel combustion has the potential of offering high thermal efficiency with low emissions; however, this may result in loud combustion noise because of the high maximum rate of pressure rise. Combustion noise and thermal efficiency work in a trade-off relation, and it has not been possible to achieve high thermal efficiency with low combustion noise, so far. Our laboratory has worked on combustion noise simulations calculated from the heat release history, and it is now possible to calculate a heat release shape for high thermal efficiency with low combustion noise. In this article, the objective of the research is the reduction of combustion noise by multiple fuel injections with high indicated thermal efficiency for a wide range of engine speeds and loads. The engine employed in the simulations and experiments is a supercharged, single-cylinder direct-injection diesel engine, with a high-pressure common rail fuel injection system. The heat release is approximated by Wiebe functions, and the combustion noise and indicated thermal efficiency are calculated in simulations. The engine operational range was divided into 12 conditions, four engine speed conditions each at three engine load conditions, and the optimum heat release shape for low combustion noise with high indicated thermal efficiency was calculated by a genetic-based algorithm method. The parameters for the genetic-based algorithm simulation were the number of injections, each injection timing, the heating value in each heat release, and the combustion period of each injection. The optimum heat release shape is a delta triangle (Δ)-shaped heat release (the heat release increase in the expansion stroke) with a high degree of constant volume for all conditions; however, the optimum number of heat releases and the injection timing are different depending on the engine speed and load conditions. The simulated results were confirmed by engine tests.

DOI： 10.1177/1468087419866069

Measurements of fuel adhesion on cylinder walls and fuel wall-flow behavior with post diesel fuel injections 査読

その他リンク： http://journals.sagepub.com/doi/full-xml/10.1177/1468087419866069

Effect of Storage Conditions on the Quality of Jatropha curcas Oils 査読

Alberto Julião Macamo, Carlos Lucas, Katia Marcos Boene, Lucrécio Biquiza, Yoshimitsu Kobashi, Satoshi Kato

Energy&Fuels 1 - 5 2020年3月

Gen Shibata, Shogo Nishiuchi, Puqing Xie, Shuntaro Takai, Hideyuki Ogawa, Yoshimitsu Kobashi

International Journal of Engine Research 21 ( 2 ) 352 - 366 2020年2月

掲載種別：研究論文（学術雑誌）出版者・発行元：SAGE Publications

Post fuel injection in the expansion stroke is used for diesel particulate filter regeneration; however, fuel spray impinges on the cylinder liner due to the low temperature and pressure conditions. Fuel adhesion and fuel flowing down across the cylinder liner, the so-called “wall-flow,” was observed by high-speed video images, and this adhesion is a cause of diesel engine lubricant oil dilution and the deterioration of fuel consumption in diesel engines. In this article, the fuel adhesion and the wall-flow of post diesel fuel injections were investigated with a high pressure-temperature constant volume optical chamber. The in-cylinder temperatures and pressures at 30, 60, and 90 °CA ATDCs, conditions commonly employed in post fuel injection timings, were measured by an actual engine, and similar conditions were created in the constant volume chamber by the combustion of a pre-mixed gas of ethylene, oxygen, and nitrogen. Fuel masses of 0.6, 1.1, and 1.7 mg per hole were injected at each ATDC setting. The weight of the adhered fuel on the wall and the fuel in the piston-cylinder crevice were measured by precision balance, and the liquid–vapor phases in the spray were observed by Mie scattering and shadowgraph methods. To measure the thickness of the adhered fuel on the cylinder wall, the laser-induced fluorescence method was employed. The results show that the fuel spray penetration and adhesion on the cylinder wall were different in the test conditions investigated here. With the early post injection, most of the injected fuel vaporizes without penetrating to the cylinder liner and gaseous diesel fuel is condensed on the cylinder wall. A thin and widely spread out fuel film is formed on the cylinder wall; however, no wall-flow could be confirmed by the high-speed video images. With late post fuel injections, the strong penetration of liquid fuel reaches the cylinder wall, and a thick and widely spread out fuel film was formed on the cylinder wall and the wall-flow phenomenon was observed here. However, the quantity of fuel involved in the wall-flow was smaller than that of the fuel adhering to the cylinder wall. The effects of in-cylinder pressure and temperature on the fuel adhesion on the cylinder wall were investigated. With the increase in pressure and temperature, the quantity of adhering fuel was reduced, suggesting that the boost pressure increase by turbo charging and a higher engine load is effective to reduce fuel adhesion. Furthermore, the effects of multiple post fuel injections on fuel adhesion to the cylinder wall were investigated, maintaining the total fuel injection amounts. With increases in the number of fuel injections, the total percentage of adhering post fuel on the cylinder wall was reduced. In the multiple fuel injections, it was observed that fuel motion takes place during the spray pass after the first and second fuel injections and that the penetration length of the second and third fuel sprays increases.

DOI： 10.1177/1468087419855200

画像相関法を用いたディーゼル噴霧火炎の乱流特性と冷却損失に関する研究

その他リンク： http://journals.sagepub.com/doi/full-xml/10.1177/1468087419855200

Modeling wall film formation and vaporization of a gasoline surrogate fuel 査読

Yoshimitsu Kobashi, Yoshio Zama, Tatsuya Kuboyama

International Journal of Heat and Mass Transfer 147 2019年11月

反射衝撃波背後における3成分ガソリンサロゲート燃料の煤生成特性査読

田中万里子, 永田勇気, 石井一洋, 小橋好充

自動車技術会論文集 50 ( 5 ) 1224 - 1229 2019年9月

An Investigation of the Effects of Engine Size and Rotation Speed on Diesel Combustion based on Similarity Rules 査読

Yoshimitsu Kobashi, Yuma Tanaka, Gen Shibata, Hideyuki Ogawa

SAE Technical Paper 2019-01-2181 2019年8月

A Study of a Lean Homogeneous Combustion Engine System with a Fuel Reformer Cylinder 査読

Go Asai, Yuki Tokuoka, Thomas Bayer, Shuntaro Ishiguro, Gen Shibata, Hideyuki Ogawa, Yoshimitsu Kobashi, Yusuke Watanabe

SAE Technical Paper 2019-01-2177 2019年8月

Study for Ignition Characteristics and Potential of Gasoline Autoignition Combustion with Spark Assist 査読

Kaname Naganuma, Koki Tanaka, Tsubasa Ito, Yoshimitsu Kobashi

SAE Technical Paper 2019-01-2317 2019年8月

Thermal Efficiency Improvements with Split Primary Fuel Injections in Semi-Premixed Diesel Combustion with Multi-Peak Shaped Heat Release 査読

Kazuki Inaba, Yosuke Masuko, Yanhe Zhang, Yoshimitsu Kobashi, Gen Shibata, Hideyuki Ogawa

SAE Technical Paper 2019-01-2170 2019年8月

Ignition Control in a Gasoline Compression Ignition Engine with Ozone Addition Combined with a Two-Stage Direct-Injection Strategy 査読

Y. Kobashi, Y. Wang, G. Shibata, H. Ogawa, K. Naganuma

Fuel 249 154 - 160 2019年8月

気筒内燃料改質ガスを用いたディーゼル混焼機関の研究（第２報）査読

朝井豪, 石黒俊太郎, 三本連太郎, 渡辺勇介, 柴田元, 小川英之, 小橋好充

自動車技術会論文集 20194559 Vol. 50 ( No. 4 ) 1030 - 1035 2019年7月

気筒内燃料改質ガスを用いたディーゼル混焼機関の研究（第１報）査読

石黒俊太郎, 朝井豪, 渡辺勇介, 柴田元, 小川英之, 小橋好充

自動車技術会論文集 20194558 Vol. 50 ( No.4 ) 1024 - 1029 2019年7月

Thermal Efficiency Improvement and its Mechanism at Low Load Conditions in Semi-Premixed Diesel Combustion with Twin Peak Shaped Heat Release 査読

Kazuki Inaba, Yosuke Masuko, Yanhe Zhang, Yoshimitsu Kobashi, Gen Shibata, Hideyuki Ogawa

SAE Technical Paper 2019-01-1153 2019年4月

アンモニアSCR用Cu-ZSM-5触媒の定常反応モデルの構築査読

永島渉, 小祝隆太郎, 柴田元, 小橋好充, 小川英之, 清水研一, 草鹿仁

自動車技術会論文集 50 ( 2 ) 323 - 327 2019年3月

画像相関法を用いたディーゼル噴霧火炎の乱流特性と冷却損失に関する研究査読

伊藤佑記, 小橋好充, 長沼要

自動車技術会論文集 50 ( 2 ) 242 - 247 2019年3月

Flash boiling spray of diesel fuel mixed with ethane and its effects on premixed diesel combustion 査読

Y. Kobashi, S. HIrako, A. Matsumoto, K. Naganuma

Fuel 237 686 - 693 2019年2月

Kinetic Modeling of Ammonia-SCR and Experimental Studies over Monolithic Cu-ZSM-5 Catalyst 査読

Wataru Eijima, Gen Shibata, Yoshimitsu Kobashi, Ryutaro Koiwai, Hideyuki Ogawa, Kenichi Shimizu, Jin Kusaka

SAE Technical Paper 2019-01-0024 2019年1月

伊藤佑記, 小橋好充, 長沼要

自動車技術会論文集 50 ( 2 ) 242 - 247 2019年

記述言語：日本語出版者・発行元：公益社団法人自動車技術会

ディーゼルエンジン燃焼室壁面からの熱伝達に及ぼす噴射圧力の影響を検討するため，噴霧火炎の輝炎に二色法と画像相関法を適用した．その結果，噴射圧力が火炎温度に及ぼす影響は小さく，高圧噴射ほど乱れの増強により冷却損失を増大させることを明らかにした．

DOI： 10.11351/jsaeronbun.50.242

Thermal Efficiency Improvement with Super-Charging and Cooled Exhaust Gas Recirculation in Semi-premixed Diesel Combustion with a Twin Peak Shaped Heat Release 査読

Kazuki Inaba, Yuto Ojima, Yosuke Masuko, Yoshimitsu Kobashi, Gen Shibata, Hideyuki Ogawa

International Journal of Engine Research 20 ( 1 ) 80 - 91 2018年12月

Flow fields and turbulent characteristics in non-evaporating diesel sprays 査読

Yoshimitsu Kobashi, Kazuhiro Yokogawa, Hiro Miyabe, Ryosuke Hase, Satoshi Kato

Atomization and Sprays 28 ( 8 ) 735 - 749 2018年10月

Thermal Efficiency Improvement with Super-Charging and Cooled EGR in Semi-premixed Diesel Combustion with a Twin Peak Shaped Heat Release 査読

Kazuki Inaba, Yuto Ojima, Yosuke Masuko, Yoshimitsu Kobashi, Gen Shibata, Hideyuki Ogawa

THIESEL 2018 Conference on Thermo- and Fluid Dynamic Processes in Direct Injection Engines 2018年9月

NH3-SCR by Monolithic Cu-ZSM-5 and Cu-AFX Catalysts: Kinetic Modeling and Engine Bench Tests 査読

Gen Shibata, Wataru Eijima, Ryutaro Koiwai, Ken-ichi Shimizu, Yuta Nakasaka, Yoshimitsu Kobashi, Yoshihiro Kubota, Masaru Ogura, Jin Kusaka

Catalysis Today 2018年6月

噴霧分配型燃焼室を用いた双峰形部分予混合化ディーゼル燃焼（第2報噴霧分配効果に対する実験的検討）査読

稲葉一輝, 小島悠人, 小橋好充, 柴田元, 小川英之

自動車技術会論文集 49 ( 2 ) 205 - 210 2018年3月

ディーゼル噴霧火炎における壁面熱損失に関する研究(第3報)燃料加熱が熱流束に及ぼす影響査読

巽健, 前田篤志, 中田将徳, 小橋好充, 桑原一成, 松村恵理子, 千田二郎

自動車技術会論文集 Transactions of Society of Automotive Engineers of Japan 49 ( 2 ) 138 - 143 2018年3月

ディーゼル噴霧火炎における壁面熱損失に関する研究(第4報)噴孔径が熱流束に及ぼす影響査読

巽健, 前田篤志, 中田将徳, 小橋好充, 松村恵理子, 千田二郎

自動車技術会論文集 Transactions of Society of Automotive Engineers of Japan 49 ( 2 ) 144 - 149 2018年3月

噴霧分配型燃焼室を用いた双峰形部分予混合化ディーゼル燃焼(第1報)CFD解析による噴霧分配特性の検討査読

稲葉一輝, 小島悠人, 小橋好充, 柴田元, 小川英之

自動車技術会論文集 Transactions of Society of Automotive Engineers of Japan 49 ( 2 ) 205 - 210 2018年3月

ディーゼル燃料過濃予混合気のピストン圧縮改質査読

朝井豪, 渡辺勇介, 石黒俊太郎, 柴田元, 小川英之, 小橋好充, 鈴木拓哉

自動車技術会論文集 20184028 Vol. 49 ( No. 1 ) 24 - 29 2018年1月

Chemical Reaction Processes of Fuel Reformation by Diesel Engine Piston Compression of Rich Homogeneous Air-Fuel Mixture 査読

Go Asai, Yusuke Watanabe, Shuntaro Ishiguro, Gen Shibata, Hideyuki Ogawa, Yoshimitsu Kobashi

SAE Paper ( 2017-32-0120 ) 2017年11月

ディーゼル噴霧火炎における壁面熱損失に関する研究(第2報) —パイロット噴射が熱流束に及ぼす影響— 査読

巽健, 前田篤志, 中田将徳, 小橋好充, 桑原一成, 松村恵理子, 千田二郎

自動車技術会論文集 48 ( 5 ) 969 - 974 2017年9月

Auto-ignition Characteristics of Gasoline Sprays with Two-Stage Injection in CI Engines 査読

Yoshimitsu Kobashi, Shuhei Yuze, Hideyuki Ogawa, Gen Shibata, Satoshi Kato, Yoshiaki Nishijima, Wakichi Kondo, Shingo Morishima, Shinichiro Kawakita, Tomoki Fujino, Takamasa Ito

COMODIA 2017 2017年7月

エタン混合燃料による減圧沸騰の効果が予混合化ディーゼル燃焼に及ぼす影響査読

松本彬良, 小橋好充, 加藤聰, 長沼要, 伊藤貴政, 川北晋一郎, 森島信悟, 近藤和吉

自動車技術会論文集 48 ( 4 ) 795 - 800 2017年7月

Development of an Ammonia-SCR Reaction Computation Model and Experimental Studies of Zeolite Catalysts 査読

Wataru Eijima, Ryutaro Koiwai, Gen Shibata, Hideyuki Ogawa, Yoshimitsu Kobashi

COMODIA 2017 2017年7月

気泡核生成モデルを考慮したノズル内キャビテーションに関する数値解析査読

村上伸吾, 稲垣良介, 小橋好充, 松村恵理子, 千田二郎

自動車技術会論文集 48 ( 3 ) 745 - 749 2017年5月

Combustion Noise Reduction with High Thermal Efficiency by the Control of Multiple Fuel Injections in Premixed Diesel Engines 査読

Gen Shibata, Hideyuki Ogawa, Yuki Okamoto, Yasumasa Amanuma, Yoshimitsu Kobashi

SAE International Journal of Engines 10 ( 3 ) 1128 - 1142 2017年3月

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

Premixed diesel combustion is effective for high thermal efficiency and reductions of NOx and PM emissions, but a reduction of combustion noise is necessary for medium-high load engine operation. The control of the fuel injection has become more accurate because of the technical progress of the common rail fuel injection system, and the target heat release shape, calculated by computation, can be achieved by control of EGR, boosting, fuel injection timing, and injection quantity of multiple fuel injections. In this paper, the reduction of premixed diesel combustion noise maintaining high thermal efficiency has been investigated by the control of injection timings and heating values of multiple fuel injections. There are two aspects of the combustion noise reduction by multiple fuel injections. One is the reduction of the maximum rate of pressure rise in each combustion cycle, and the other is noise reduction effects by the noise cancelling spike (NCS) combustion. The research was conducted with both engine simulations and experiments. In combustion noise simulations, the heat release history of multiple injections was approximated by Wiebe functions and the simulated combustion noise was calculated from the fitted curve of the heat release and the coherence transfer function. The structural attenuation (SA) of the test engine was calculated from the power spectrum of the FFT analysis of the in-cylinder pressure wave data and the cross power spectrum of the sound pressure of the engine noise by the coherence method, then the combustion noise (CNL) can be calculated from the structural attenuation and cylinder pressure level (CPL) in the simulation, as shown in equation 4. The simulation results were confirmed by the engine tests. First, the combustion noise reduction by two stage fuel injection was investigated. The maximum rate of pressure rise changes depending on the combustion occurring separately in the compression and expansion strokes. One heat release was set at TDC and the second before or after the TDC. In the late two stage combustion as shown in Figure 12 (b), the combustion noise reduction was most effectively achieved when the heating value of Q2nd is higher than that of Q1st, however in the early two stage combustion in Figure 12 (a), the Q1st heat release occurs during the compression stroke and the combustion noise reduction by the early two stage NCS combustion is more effective than the combustion noise reduction by the late two stage NCS combustion. Three stage combustion simulations were also investigated at 0.6MPa IMEP and 2000 rpm. The optimum heat release shape for low combustion noise and high indicated thermal efficiency was calculated and the role of each part of the heat release in the three stage combustion is discussed. The simulation predicted 87.1 dBA of combustion noise and 50.3 % of indicated thermal efficiency. Finally, the effects of multiple fuel injections on the degree of constant volume and combustion noise are analyzed and discussed.

DOI： 10.4271/2017-01-0706

ゼオライト触媒を用いたNH3-SCR 反応モデルの開発査読

永島渉, 小祝隆太郎, 柴田元, 小川英之, 小橋好充, 草鹿仁, 植西徹

自動車技術会論文集 48 ( 2 ) 299 - 304 2017年3月

詳細反応機構の解読にもとづくノルマルトリデカンの簡略化反応機構の構築査読

桑原一成, 松尾直, 酒井康行, 小橋好充, 堀司, 松村恵理子, 千田二郎

自動車技術会論文集 48 ( 1 ) 27 - 33 2017年1月

An Investigation of the Transient DPF Pressure Drop under Cold Start Conditions in Diesel Engines 査読

Yoshimitsu Kobashi, Shun Oooka, Lin Jiang, Jun Goto, Hideyuki Ogawa, Gen Shibata

SAE Technical Papers 2017- 2017年

担当区分：筆頭著者記述言語：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：SAE International

To monitor emission-related components/systems and to evaluate the presence of malfunctioning or failures that can affect emissions, current diesel engine regulations require the use of on-board diagnostics (OBD). For diesel particulate filters (DPF), the pressure drop across the DPF is monitored by the OBD as the pressure drop is approximately linear related to the soot mass deposited in a filter. However, sudden acceleration may cause a sudden decrease in DPF pressure drop under cold start conditions. This appears to be caused by water that has condensed in the exhaust pipe, but no detailed mechanism for this decrease has been established. The present study developed an experimental apparatus that reproduces rapid increases of the exhaust gas flow under cold start conditions and enables independent control of the amount of water as well as the gas flow rate supplied to the DPF. The results show that the sudden decrease in the DPF pressure drop is caused by the water in the developed system used here. Observations of the soot cake layers in the DPF show that the decrease in the DPF pressure drop is caused by peeling-off and separation of the soot cake layer from the walls of the DPF. An increase in the water flow rate thins the soot cake layer and decreases the DPF pressure drop. Further, numerical simulation using a DPF model developed by a research group at Waseda University was also performed, and the calculated DPF pressure drop captures the changes obtained by the experiments well.

DOI： 10.4271/2017-01-2372

ディーゼル噴霧火炎における壁面熱損失に関する研究 —噴射圧力が熱流束に及ぼす影響— 査読

巽健, 前田篤志, 宮田哲次, 小橋好充, 桑原一成, 松村恵理子, 千田二郎

自動車技術会論文集 47 ( 6 ) 1291 - 1296 2016年

Reduction of Reaction Mechanism for n -Tridecane Based on Knowledge of Detailed Reaction Paths 査読

Kazunari Kuwahara, Tadashi Matsuo, Yasuyuki Sakai, Yoshimitsu Kobashi, Tsukasa Hori, Eriko Matsumura, Jiro Senda

SAE Technical Papers 2016- 2016年

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：SAE International

n-Tridecane is a low boiling point component of gas oil, and has been used as a single-component fuel for diesel spray and combustion experiments. However, no reduced chemical kinetic mechanisms for n-tridecane have been presented for three-dimensional modeling. A detailed mechanism developed by KUCRS (Knowledge-basing Utilities for Complex Reaction Systems), contains 1493 chemical species and 3641 reactions. Reaction paths during ignition process for n-tridecane in air computed using the detailed mechanism, were analyzed with the equivalence ratio of 0.75 and the initial temperatures of 650 K, 850 K, and 1100 K, which are located in the cool-flame dominant, negative-temperature coefficient, and blue-flame dominant regions, respectively. Based on knowledge derived from the reaction path analysis, a skeletal mechanism containing 49 species and 85 reactions, was developed and validated for representing ignition characteristics over a wide range of initial conditions computed using the detailed mechanism. The skeletal mechanism includes C3H7, C2H5, and CH3 as representative fragmental alkyl radicals, C7H14, C3H6, and C2H4 as representative alkenes, and C3H7CHO and CH2O as representative aldehydes. C3-series reactions beginning with O2 addition to C3H7, were expressed using parameters for C6-series reactions, which took similar reactions for larger alkyl radicals into consideration. Ignition delay times and low-temperature oxidation induction times with the initial temperatures between 600 K and 1200 K using the skeletal mechanism, and their dependences on pressure and equivalence ratio in lean and stoichiometric cases agree well with those using the detailed mechanism. However, the agreement becomes worse as equivalence ratio is increased in rich cases.

DOI： 10.4271/2016-01-2238

ガソリン系燃料のオクタン価が二燃料成層自着火の着火と燃焼過程に及ぼす影響査読

武藤涼, 髙木圭一朗, 横川和弘, 小橋好充, 加藤聰

自動車技術会論文集 47 ( 2 ) 299 - 305 2016年

化学反応速度論にもとづくオクタン価リファレンス燃料の着火遅れ式（第２報） −低温酸化反応を経由する低温条件の着火過程− 査読

中谷匡希, 桑原一成, 多田卓矢, 古谷正広, 小橋好充, 酒井康行, 松村恵理子, 千田二郎

自動車技術会論文集 47 ( 1 ) 9 - 15 2016年

ガソリン圧縮着火燃焼における二段噴射の役割査読

小橋好充, 松本彬良, 武藤涼, 加藤聰, 藤野友基, 川北晋一郎, 近藤和吉, 西島義明

自動車技術会論文集 47 ( 1 ) 87 - 92 2016年

Premixed Fuel Effect on Ignition and Combustion of Dual Fuel Compression Ignition Engine 査読

Yoshimitsu Kobashi, Ryo Muto, Satoshi Kato

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

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：SAE International

Effects of chemical reaction characteristics of premixed fuel were experimentally studied in a dual fuel compression ignition engine using port injection (PI) of gasoline-like component and direct injection (DI) of diesel fuel. Octane number of port injection fuels, direct injection timing and injection amount ratio between PI and DI were swept to assess the interaction between chemical reaction and mixture distribution in a combustion chamber. Chemical kinetic study using multi-zone modeling was also performed in order to explain experimental results under quiescent condition.

DOI： 10.4271/2015-01-1789

Artificial Control of Diesel Spray and Flame Feature by using Dual-component Fuel 査読

Satoshi Miyata, Yu Kuwahara, Yoshimitsu Kobashi, Kazunari Kuwahara, Eriko Matsumura, Jiro Senda

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

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：SAE International

Fuel design approach has been proposed as the control technique of spray and combustion processes in diesel engine to improve thermal efficiency and reduce exhaust emissions. In order to kwow if this approach is capable of controlling spray flame structure and interaction between the flame and a combustion chamber wall, the present study investigated ignition and flame characteristics of dual-component fuels, while varying mixing fraction, fuel temperature and ambient conditions. Those characteristics were evaluated through chemiluminescence photography and luminous flame photography. OH radical images and visible luminous flame images were analyzed to reveal flame shape aspect ratio and its fractal dimension.

DOI： 10.4271/2015-01-1916

種々の二成分混合燃料を用いたディーゼル燃焼における着火および火炎構造に関する研究査読

千田二郎, 味岡将士, 向山智之, 宮田哲次, 桑原悠, 小橋好充, 桑原一成, 松村恵理子

自動車技術会論文集 46 ( 2 ) 349 - 354 2015年3月

ジャトロファ油／灯油混合燃料を用いたコモンレール式ディーゼル機関の特性査読

朝香勝義, 横川和弘, 小橋好充, 加藤聰, 鈴木康允, Alberto MACAMO

日本機械学会論文集 81 ( 824 ) 2015年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：The Japan Society of Mechanical Engineers

Oil derived from Jatropha is a potential alternative to fossil fuels for Diesel engines in Mozambique because it can be cheaper and more easily available than fatty acid methyl ester, though the physical properties, e.g. high viscosity, might be a problem. As an attempt to use Jatropha oil (JO) in Diesel engines, the present study mixed JO into kerosene. Engine tests as well as un-evaporating spray visualization were carried out. The results demonstrated that a single cylinder engine can be successfully operated with JO blended kerosene despite the fact that the ignition delay is slightly longer than diesel fuel. There were no significant changes of exhaust gas emissions. It is also clear that mixing JO into kerosene can contribute to the reductions of insoluble fraction and soluble organic fraction contained in particulate matter than mixing into diesel fuel.

DOI： 10.1299/transjsme.14-00527

A Comparative Analysis of Combustion Process, Performance and Exhaust Emissions in Diesel Engine Fueled with Blends of Jatropha Oil-Diesel Fuel and Jatropha Oil-Kerosene 査読

Takaaki Yamaji, Katsuyoshi Asaka, Yoshimitsu Kobashi, Satoshi Kato, Yasumitsu Suzuki, Albert Macamo

SAE Technical Paper 2015-32-0797 2015年

Analysis of Turbulence in Diesel Spray Using Time-Resolved PIV 査読

Kazuyoshi.Yokogawa, Yoshimitsu.Kobashi, Satoshi.Kato

13th Triennial International Conference on Liquid Atomization and Spray Systems 2015年

化学反応速度論にもとづくオクタン価リファレンス燃料の着火遅れ式 −低温酸化反応を経由しない高温条件の着火過程− 査読

桑原一成, 多田卓矢, 古谷正広, 大嶋元啓, 小橋好充, 酒井康行, 安東弘光, 松村恵理子, 千田二郎

自動車技術会論文集 46 ( 5 ) 851 - 857 2015年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人自動車技術会

KUCRS が提供する詳細反応モデルを用いてノルマルヘプタンとイソオクタンのそれぞれについて着火遅れ式を導出する．この着火遅れ式は，着火遅れ時間の燃料濃度依存性，酸素濃度依存性，第三体濃度依存性，熱容量依存性などを分離して記述し，シリンダー内のあらゆる着火現象に適用することを想定したものである．

DOI： 10.11351/jsaeronbun.46.851

Exhaust Emission Characteristics of Diesel Engine Using Jatropha Crude Oil Blends 査読

Satoshi Kato, Yoshimitsu Kobashi, Yasumitsu Suzuki, Koji Tosa, Katsuyoshi Asaka, Alberto Macamo

SAE Technical Papers 2014- 2014年10月

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：SAE International

Jatropha biofuel is promising renewal oil to produce biodiesel fuel through transesterification method which is shown in many papers. The ideal diesel alternative fuel obtained considering Jatropha as materials is Fatty Acid Methyl Ester (FAME). It is more desirable than the viewpoint of economical efficiency and CO&lt
inf&gt
2&lt
/inf&gt
control to operate a diesel engine with Jatropha crude (JC) oil. It is the purpose of this research to examine a possibility of using advantageous JC oil direct use as diesel engine fuel, in consideration of the sustainable production of the Jatropha biofuel in Mozambique. The adaptability to the diesel engine of diesel oil and the mixed fuel of JC was examined. Jatropha crude oil contains phorbol ester (PEs) which is a promoter of cancer. Measurement of the concentration of PEs in an exhaust gas was performed using High Performance Liquid Chromatography (HPLC). Skip cycle operation was performed for diesel engine with an electronically-controlled fuel injection system, and it was checked that the PEs concentration in the exhaust gas in low load operation which imitated cold starting condition. As a result of conducting the experiment by the JC mixed fuel up to JC60 had little influence on indicated thermal efficiency and the exhaust gas components except PM, and it has checked the possibility of utilization. However, PM in an exhaust gas increased in proportion to the mixed ratio of JC. Also in the skip cycle which imitated cold starting, it checked that the PEs concentration in an exhaust gas was below a detection limit.

DOI： 10.4271/2014-01-2770

Experimental Validation of a Droplet Vaporization Model for Ethanol-Blended Fuels and its Application to Spray Simulation 査読

Yoshimitsu Kobashi, Yusuke Kimoto, Satoshi Kato

SAE Technical Papers 2014- 2014年10月

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：SAE International

Ethanol is a promising alternative to fossil fuels because it can be made from biomass resources that are renewable. In the most cases, however, ethanol is blended with conventional fuels because of the limited amount of production. Ethanol-fuel blends are typically azeotropic and have a unique characteristic in vapor pressure and phase equilibrium, which is different from that of blends composed of simple aliphatic hydrocarbons. The current studies by the authors have developed a numerical vaporization model for ethanol-gasoline blends, which takes into account vapor-liquid equilibrium of azeotrope and high latent heat of vaporization of ethanol, in order to update the authors' multicomponent fuel spray model and to investigate effects of blending ethanol on droplet vaporization processes. In this paper, the developed vaporization model was validated through a comparison with experimentally-observed vaporization rate for single droplets of ethanol-n-heptane blends. The predicted results were in a good agreement with experimental data. The results also showed that the latent heat of vaporization of ethanol plays an important role in a droplet vaporization rate while the increase of the vapor pressure due to mixing ethanol has less effect and that consideration of the phase equilibrium composition is required to correctly predict the temporal change of the composition in a vaporizing droplet. Finally, the developed vaporization model was incorporated into authors' multicomponent fuel spray model. The effects of liquid-vapor equilibrium of ethanol-n-heptane blends and the latent heat of vaporization of ethanol were evaluated for vaporizing fuel spray.

DOI： 10.4271/2014-01-2733

ジャトロファ油混合燃料を用いたディーゼル機関の特性と排気微粒子中のホルボールエステル査読

小橋好充, 朝香勝義, 加藤佳也, 加藤聰, 土佐光司, 鈴木康允

自動車技術会論文集 45 ( 2 ) 185 - 190 2014年3月

エタノール-ノルマルヘプタン混合燃料の液滴蒸発モデルの評価と蒸発噴霧への適用査読

木本裕輔, 小橋好充, 加藤聰

自動車技術会論文集 45 ( 5 ) 817 - 822 2014年

Numerical simulation of evaporating sprays of ethanol fuel blends 査読

Yoshimitsu Kobashi, Yusuke Kimoto, Satoshi Kato

SAE Technical Papers 11 2013年

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）

Ethanol is a promising alternative to fossil fuels because it can be produced from biomass resources that are renewable. Due to the amount of production, however, the usage would be limited to blends with other conventional fuels. Ethanol-fuel blends are azeotropic and have unique vaporization characteristics different from blends composed of aliphatic hydrocarbons, so that the present study developed a numerical scheme which takes into account the vapor-liquid equilibrium of azeotrope in order to update the author's original version of the multi-component fuel CFD model and to evaluate the effect of mixing ethanol into gasoline on the evaporation process. The numerical simulation was implemented for evaporating sprays of ethanol-n-heptane blends, which are injected through a single hole nozzle. In addition to the vapor-liquid equilibrium, the effect of the latent heat of vaporization was investigated. The result clearly shows the effect of azeotropic phenomenon on the evaporation process while indicating that the latent heat of vaporization plays more significant role on the evaporation for the case of higher mixing fraction of ethanol. Copyright © 2013 SAE International and Copyright © 2013 KSAE.

DOI： 10.4271/2013-01-2552

SPRAY VAPORIZATION AND IGNITION CHARACTERISTICS IN DUAL-COMPONENT MIXED FUELS 査読

Chang-Eon Lee, Seungro Lee, Masanori Okada, Masashi Matsumoto, Yoshimitsu Kobashi, Jiro Senda

ATOMIZATION AND SPRAYS 23 ( 2 ) 141 - 164 2013年

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

In this study, the ignition characteristics and vaporization characteristics of a dual-component mixed fuel composed of low boiling temperature (LBT) fuels were investigated experimentally in terms of fuel composition and mass fraction (Y-LBT) using a constant volume combustion vessel. For this purpose, two groups of mixed fuels were tested: The first group was a mixture of the high boiling temperature (HBT) fuel nC13 as the base fuel and various LBT fuels with similar BTs ranging from 350 to 380 K but with different ignition temperatures (ITs), and second group was a mixture of HBT fuel and various LBT fuels with ITs similar to the IT of nC13 but different BTs. The results indicate that although the type and mass fraction of the LBT fuels in the dual-component mixed fuels were varied, small changes in density did not produce changes in the spray behavior of the fuels, which is described by the spray tip penetration under the no-combustion condition. The ignition delay times for nearly all of the mixed fuels were the same as the delay time of pure nC(13) below Y-LBT = 0.5; however, the ignition delay times rapidly increased with the characteristics of the boiling curve diagrams of the mixed fuels.

DOI： 10.1615/AtomizSpr.2013007513

Web of Science

二成分混合燃料噴霧による圧縮着火機関の圧力上昇率およびエミッションの低減査読

直接噴射方式におけるノズル内キャビテーションが噴霧特性に及ぼす影響（第2報：供試液体中の溶存空気濃度を変化させた際の衝撃加速度と噴流の関係) 査読

松本雅至, 井上欣也, 安富友香, 小橋好充, 松村恵理子, 神田睦美, 千田二郎

日本機械学会論文集(B編) 79 ( 806 ) 2160 - 2169 2013年

前川浩輝, 小橋好充, 加藤聰, 千田二郎

自動車技術会論文集 43 ( 6 ) 1263 - 1268 2012年11月

Simultaneous Reduction of Pressure Rise Rate and Emissions in a Compression Ignition Engine by Use of Dual-Component Fuel Spray 査読

Yoshimitsu Kobashi, Hiroki Maekawa, Satoshi Kato, Jiro Senda

SAE International Journal of Fuels and Lubricants 5 ( 3 ) 1404 - 1413 2012年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ignition, combustion and emissions characteristics of dual-component fuel spray were examined for ranges of injection timing and intake-air oxygen concentration. Fuels used were binary mixtures of gasoline-like component i-octane (cetane number 12, boiling point 372 K) and diesel fuel-like component n-tridecane (cetane number 88, boiling point 510 K). Mass fraction of i-octane was also changed as the experimental variable. The experimental study was carried out in a single cylinder compression ignition engine equipped with a common-rail injection system and an exhaust gas recirculation system. The results demonstrated that the increase of the i-octane mass fraction with optimizations of injection timing and intake oxygen concentration reduced pressure rise rate and soot and NOx emissions without deterioration of indicated thermal efficiency. Numerical investigation into the pressure rise rate reduction mechanism was also performed by use of a multi-component fuel model developed by the authors. The calculated result showed that the pressure rise rate was reduced due to the difference in the vapor concentrations between two components which have difference reactivity. © 2012 SAE Japan.

DOI： 10.4271/2012-32-0031

Effects of Fuel Composition on Flame Lift-off Length and Pollutant Formation in Dual-component Fuel Spray 査読

Masanori Okada, Daisuke Shigetomi, Masashi Matsumoto, KOBASHI, YOSHIMITSU, Jiro Senda

The Proceedings of the Eighth International Conference on Modeling and Diagnostics for Advanced Engine Systems (COMODIA) 323 - 328 2012年7月

着火性の異なる燃料の二段噴射により形成される混合気分布がPCCI燃焼の着火・燃焼過程に及ぼす影響査読

松本雅至, 岸裏雅登, 小橋好充, 松村恵理子, 千田二郎

自動車技術会論文集 43 ( 4 ) 875 - 880 2012年7月

Chemical Thermodynamics Modeling of Vaporization and Ignition Processes in Dual-component Fuel Spray 査読

Masashi Matsumoto, Chang Eon-Lee, Daisuke Shigetomi, Masanori Okada, KOBASHI, YOSHIMITSU, Jiro Senda

The Proceedings of the Eighth International Conference on Modeling and Diagnostics for Advanced Engine Systems (COMODIA) 635 - 640 2012年7月

各種アルコール燃料の混合がバイオディーゼル燃料の燃焼特性に及ぼす影響査読

松浦貴, 小橋好充, 桑原一成, 千田二郎

自動車技術会論文集 43 ( 2 ) 455 - 460 2012年3月

二成分混合燃料噴霧の着火・燃焼機構と燃焼制御性に関する数値解析査読

小橋好充, 藤森健太, 前川浩輝, 加藤聰, 川野大輔, 千田二郎

自動車技術会論文集 43 ( 1 ) 123 - 128 2012年1月

二燃料の混合気濃度と燃焼位相が圧縮着火機関の性能・排気特性に及ぼす影響査読

小橋好充, 田中大二郎, 丸小鉄平, 加藤聰

日本機械学会論文集(B編) 78 ( 788 ) 939 - 947 2012年

直接噴射方式におけるノズル内キャビテーションが噴霧特性に及ぼす影響（第1報：噴射圧力および供試液体の飽和蒸気圧を実験変数とした噴孔内圧力の計測）査読

松本雅至, 井上欣也, 小橋好充, 松村恵理子, 千田二郎

日本機械学会論文集(B編) 78 ( 794 ) 1759 - 1768 2012年

Simultaneous reduction of pressure rise rate and emissions in a compression ignition engine by use of dual-component fuel spray

Yoshimitsu Kobashi, Hiroki Maekawa, Satoshi Kato, Jiro Senda

SAE Technical Papers 4 2012年

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：SAE International

Modeling of Auto-Ignition and combustion processes for dual-component fuel spray 査読

Yoshimitsu Kobashi, Kenta Fujimori, Hiroki Maekawa, Satoshi Kato, Daisuke Kawano, Jiro Senda

SAE International Journal of Engines 4 ( 2 ) 2193 - 2206 2011年8月

記述言語：英語掲載種別：研究論文（学術雑誌）

Auto-ignition and combustion processes of dual-component fuel spray were numerically studied. A source code of SUPERTRAPP (developed by NIST), which is capable of predicting thermodynamic and transportation properties of pure fluids and fluid mixtures containing up to 20 components, was incorporated into KIVA3V to provide physical fuel properties and vapor-liquid equilibrium calculations. Low temperature oxidation reaction, which is of importance in ignition process of hydrocarbon fuels, as well as negative temperature coefficient behavior was taken into account using the multistep kinetics ignition prediction based on Shell model, while a global single-step mechanism was employed to account for high temperature oxidation reaction. Computational results with the present multi-component fuel model were validated by comparing with experimental data of spray combustion obtained in a constant volume vessel. The results showed a good agreement in terms of spray tip penetration, liquid length, ignition delay and so on, for several kinds of dual-component fuels. Additional investigation into a combustion control methodology using dual-component fuel, which aims to mitigate combustion rate of premixed charge, was performed. Consequently, the feasibility of this approach was confirmed. © 2011 SAE International.

DOI： 10.4271/2011-24-0001

急速圧縮膨張装置を用いた二段噴射燃料の着火・燃焼過程に関する研究査読

小橋好充, 城戸良仁, 岸裏雅登, 千田二郎, 藤本元, 柴田元

自動車技術会論文集 42 ( 2 ) 477 - 482 2011年3月

Chemical kinetics study on ignition characteristics of biodiesel surrogates 査読

Kazunari Kuwahara, Koryu Nakahara, Yoshimitsu Wada, Jiro Senda, Yasuyuki Sakai, Hiromitsu Ando

SAE Technical Papers 780 - 797 2011年

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）

Methyl butanoate (MB) and methyl decanoate (MD) are surrogates for biodiesel fuels. According to computational results with their detailed reaction mechanisms, MB and MD indicate shorter ignition delays than long alkanes such as n-heptane and n-dodecane do at an initial temperature over 1000 K. The high ignitability of these methyl esters was computationally analyzed by means of contribution matrices proposed by some of the authors. Due to the high acidity of an α-H atom in a carbonyl compound, hydroperoxy radicals are generated out of the equilibrium between forward and backward reactions of O2 addition to methyl ester radicals by the internal transfer of an α-H atom in the initial stage of an ignition process. Some of the hydroperoxy methyl ester radicals can generate OH to activate initial reactions. MB has an efficient CH3O formation path via CH3 generated by the β-scission of an MB radical which has a radical site on the α-C atom to the carbonyl group. MB has also other CH3O formation paths via some of fragmental oxygenated radicals. Therefore, the CH3O concentration is remarkably high in a thermal ignition preparation phase. The rich CH3O decomposes into CH2O and H, and then H combines with O2 into HO2. This exothermic reaction, H + O 2 + M = HO2 + M, plays a key role in promoting initial heat release. MD has efficient paths for initial heat release starting from the O2 addition to some of fragmental methyl ester radicals and ending in the OH formation via the internal transfer of an α-H atom. These paths considerably contribute not only to promoting initial heat release but also to generating OH in the initial stage of an ignition process. In conclusion, these mechanisms for the high ignitability are caused by a common local structure of methyl ester molecules, a carbonyl group in the molecule. © Copyright 2011 Society of Automotive Engineers of Japan, Inc. and SAE International.

DOI： 10.4271/2011-01-1926

Effects of mixedness and ignition timings on PCCI combustion with a dual fuel operation 査読

Yoshimitsu Kobashi, Daijiro Tanaka, Teppei Maruko, Satoshi Kato, Masato Kishiura, Jiro Senda

SAE Technical Papers 699 - 713 2011年

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）

A dual fuel operation with different reactivity fuels has the possibility of optimizing performance and emissions in premixed charge compression ignition engines by controlling the spatial concentration and distribution of both fuels. In the present study, n-heptane and i-octane were independently injected through two different injectors. In-cylinder pressure analysis and emissions measurement were performed in a compression ignition engine. Injection timings, fuel quantity ratio between the injections were changed for the two cases, in which one fuel was injected using a port fuel injection system while the other was directly injected into the cylinder, in order to drastically vary mixture distributions and ignition timings. In addition, an optical diagnostic was performed in a rapid compression and expansion machine to develop an understanding of the ignition processes of the two mixtures. The experimental results show that not only the mixedness of the more reactive fuel n-heptane but also that of the less reactive fuel i-octane have significant impacts on the ignition timings, burn rates and emissions. As a first step to establish an optimum method of controlling burn rate, engine performance and emissions formation processes, the present study developed an understanding of the effects of the mixture distributions and ignition timings of two fuels on emissions and thermal efficiency. © Copyright 2011 Society of Automotive Engineers of Japan, Inc. and SAE International.

DOI： 10.4271/2011-01-1768

Visualization of the cavitating flow inside the nozzle hole using by enlarged acrylic nozzle 査読

M. Matsumoto, Y. Inoue, E. Matsumura, Y. Kobashi, J. Senda

SAE Technical Papers 1644 - 1653 2011年

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）

In this study, it is purpose to make clear the effect of cavitation phenomenon on the spray atomization. In this report, the cavitation phenomenon inside the nozzle hole was visualized and the pressure measurements along the wall of the nozzle hole were carried out by use of 25-times enlarged acrylic nozzle. For the representatives of regular gasoline, single and two-component fuels were used as a test fuel. In addition, various cavitating flow patterns same as experimental conditions were simulated by use of Barotropic model incorporated in commercial code of Star-CD scheme, and compared with experimental results. © Copyright 2011 Society of Automotive Engineers of Japan, Inc. and SAE International.

DOI： 10.4271/2011-01-2062

直接サンプリングによるDIディーゼル機関の燃焼室内PMにDMC添加燃料が及ぼす影響解析査読

五十嵐智紀, 田浦寛斉, 小橋好充, 加藤聰

自動車技術会論文集 41 ( 6 ) 1335 - 1340 2010年11月

Spatial-Temporal Combustion Control in a CI Engine Based on Two-Stage Fuel Injection : Fundamental Study in a Rapid Compression and Expansion Machine 査読

KOBASHI, YOSHIMITSU, Yoshihito KIDO, Masato KISHIURA, Yoji Oyama, Masashi MATSUMOTO, Jiro SENDA, Hajime Gen, FUJIMOTO

THIESEL 2010 Conference on Thermo- and Fluid Dynamic Processes in Diesel Engines 235 - 251 2010年9月

Proposal on Controlled Spray Evaporation and Mixture Formation by Use of Multi-Component Mixing Fuel Spray Model 査読

KOBASHI, YOSHIMITSU, Masashi MATSUMOTO, Eriko MATSUMURA, Jiro SENDA

International Council on Combustion Engines (CIMAC2010) ( 118 ) 1 - 15 2010年6月

Feasible Study of Spray and Combustion Control Using Dual Component Fuel Based on Multicomponent Spray Model 査読

International Conference on Liquid Atomization and Spray Systems 2009年7月

二成分混合燃料の減圧沸騰噴霧を用いた部分予混合燃焼に関する研究査読

和田好充, 真柄紀幸, 大山洋司, 千田二郎, 藤本元

自動車技術会論文集 40 ( 1 ) 123 - 128 2009年1月

Demonstrating the potential of mixture distribution control for controlled combustion and emissions reduction in premixed charge compression ignition engines 査読

Yoshimitsu Wada, Jiro Senda

SAE Technical Papers 2009年

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）

The objective of this study is to explore the relation among mixture distribution condition, chemical character of fuel, combustion processes, and emissions characteristics with premixed charge compression ignition (PCCI) operation. The present experiment employs two fuel injectors which are capable of port injection and direct one. The former was used to supply a highly-homogeneous mixture and the latter with late injection timing was employed to control the mixture heterogeneity. Thus, these sets of injection equipments are capable of setting a wide variety of mixture heterogeneity. Furthermore, two primary reference fuels were used in order to know the influences of chemical character. The experiments were conducted in order to clarify the combustion and emissions characteristics through engine tests. Optical diagnostic was also performed to gain additional insight into the combustion processes for a wide variety of mixture distribution. The results using the port injection showed that the steepness of the combustion was affected by the local equivalence ratio rather than the overall one. The double injection using both injection equipments demonstrated that the ignition source was the mixture formed by the direct injection and there was the optimum mass fraction of direct injection to reduce the maximum pressure rise rate in the case of combination of lower octane number fuel and lower compression ratio. In contrast, the different tendency was observed for the combination of higher octane number fuel and higher compression ratio. Copyright © 2009 SAE International.

DOI： 10.4271/2009-01-0498

ポート噴射と直接噴射の各種組み合わせにおけるPCCI燃焼の時空間的進行過程と排出ガス特性査読

小橋好充, 上田圭佑, 城戸良仁, 千田二郎, 藤本元

日本機械学会論文集(B編) 75 ( 759 ) 2329 - 2337 2009年

Combustion Control in DI Compression Ignition Engines with Partially Premixed Charge Operation Using Flashing Spray of Mixed Fuel 査読

Yoshimitsu Wada, Noriyuki Magara, Jiro Senda, Hajime Gen Fujimoto

International Conference on Modeling and Diagnostics for Advanced Engine Systems (COMODIA) 151 - 158 2008年7月

各種脂肪酸メチルエステルのディーゼル噴霧燃焼特性に関する実験的研究(第2報)－噴霧の巨視的特性およびすす生成特性に関する基礎解析－査読

池田智樹, 羽原輝晃, 桜井翔, 和田好充, 鶴谷和司, 千田二郎, 藤本元

自動車技術会論文集 39 ( 2 ) 269 - 274 2008年3月

各種脂肪酸メチルエステルのディーゼル噴霧燃焼特性に関する実験的研究(第1報)－着火特性および熱発生率の基礎解析－査読

池田智樹, 羽原輝晃, 桜井翔, 和田好充, 千田二郎, 藤本元, 鶴谷和司

自動車技術会論文集 39 ( 2 ) 263 - 268 2008年3月

Improvement of combustion and emissions in diesel engines by means of enhanced mixture formation based on flash boiling of mixed fuel 査読

J. Senda, Y. Wada, D. Kawano, H. Fujimoto

INTERNATIONAL JOURNAL OF ENGINE RESEARCH 9 ( 1 ) 15 - 27 2008年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PROFESSIONAL ENGINEERING PUBLISHING LTD

A novel approach to reduce diesel engine emissions at relatively low injection pressures is proposed. This approach is based on the use of a mixed fuel where an additive or a low boiling point fuel such as CO(2), gas fuel, or gasoline is mixed with a higher boiling point fuel such as diesel gas oil. When producing such a fuel, the vapour-liquid equilibrium in the two-phase region where the liquid and vapour phases of both components coexist is taken into account. In designing a mixed fuel, the authors intend to control both the physical process in the spray such as fuel evaporation and vapour air mixing and the chemical processes including spontaneous ignition and with reactions with regard to NO(x), particulate matter (PM), and hydrocarbon (HC) formation. In this study flash boiling of mixed fuel is particularly focused on enhancing the mixing process in the spray because it has the potential to achieve fast evaporation and relatively lean and homogeneous mixtures. Experiments were carried out using two types of mixed fuel, both of which can generate flash boiling during injection events. In an experiment using a rapid compression machine (RCM) and an optical engine, mixed fuels consisting of liquefied CO(2) as an additive and n-tridecane representing gas oil were employed with the aim of simultaneously reducting soot and NO(x) emissions. The high-speed images acquired for sprays reacting in the RCM and the engine clearly showed a significant reduction of soot formation in the spray. Reductions of soot and NO(x) emissions as well as the fuel consumption were also confirmed by emission measurements and a combustion analysis respectively. In other experiments, different types of mixed fuel consisting of gas or gasoline and gas oil were tested to see the effects on both the evaporation and ignition processes. The result of an engine experiment showed marked reductions of soot and HC emissions and fuel consumption.

DOI： 10.1243/14680874JER02007

Web of Science

混合燃料による予混合圧縮着火機関の燃焼制御(第1報)－種々の過熱度および雰囲気条件下における減圧沸騰噴霧の特性－査読

Controlling PCCI Combustion with Mixed Fuel - Effect of Fuel Ignitability, Compression Ratio and Charge Heterogeneity- 査読

Yoshimitsu Wada, Keisuke Ueda, Naoki Kitamura, Noriyuki Magara, Yuji Nishimura, Jiro Senda, Hajime Fujimoto

Review of Automotive Engineering 29 ( 29 ) 65 - 71 2008年1月

混合燃料による予混合圧縮着火燃焼の制御－燃料の着火性、混合気濃度不均一性および圧縮比の影響－査読

和田好充, 上田圭佑, 北村直樹, 真柄紀幸, 西村優史, 千田二郎, 藤本元

自動車技術会論文集 38 ( 6 ) 59 - 64 2007年11月

Controlling PCCI Combustion with Mixed Fuel - Application of Flashing Spray to Early Injection - 査読

KOBASHI, YOSHIMITSU, Yuji Nishimura, Akihiro Yamaguchi, Noriyuki Magara, Jiro Senda, Hajime Fujimoto

SAE Technical Paper, No. 2007-01-0624 1 - 19 2007年4月

燃料の着火性と濃度不均一性が直接噴射式PCCI機関の燃焼特性・運転範囲に及ぼす影響査読

和田好充, 沖本和樹, 北村直樹, 上田圭佑, 千田二郎, 藤本元

日本機械学会論文集(B編) 73 ( 728 ) 1121 - 1128 2007年4月

Spray and Combustion Characteristics for Reformulated Mixing Fuel of Biodiesel with Lower Boiling Point Fuel 査読

Jiro Senda, Tomoki Ikeda, Teruaki Haibara, Sho Sakurai, KOBASHI, YOSHIMITSU, Hajime Fujimoto

SAE Technical Paper, No. 2007-01-0621 1 - 11 2007年4月

和田好充, 山口晃弘, 西村優史, 真柄紀幸, 尹俊圭, 千田二郎, 藤本元

自動車技術会論文集 38 ( 1 ) 85 - 90 2007年1月

混合燃料による予混合圧縮着火機関の燃焼制御(第2報)－減圧沸騰噴霧の適用による燃焼改善－査読

和田好充, 西村優史, 山口晃弘, 真柄紀幸, 千田二郎, 藤本元

自動車技術会論文集 38 ( 1 ) 91 - 96 2007年1月

Effect of octane rating and charge stratification on combustion and operating range with di PCCI operation 査読

Yoshimitsu Wada, Kazuki Okimoto, Naoki Kitamura, Keisuke Ueda, Jiro Senda, Hajime Fujimoto

SAE Technical Papers 1 - 13 2007年

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）

A single cylinder engine has been run with direct-injection premixed charge compression ignition (PCCI) operation. The operation is fueled with primary reference fuels for a wide variety of injection timing and equivalence ratio to investigate the effect of charge stratification and octane rating on PCCI combustion. The test results showed that although the change of the injection timing can gain the high combustion efficiency for a wide range of equivalence ratio, the combustion phasing where the high combustion efficiency is accomplished is not varied only by changing the injection timings. Therefore, the only change of injection timings does not improve the thermal efficiency which is influenced by the combustion phasing. On the other hand, at the fixed compression ratio, inlet air temperature and so on, the octane rating is useful in altering the combustion phasing. The experiments in which the octane rating was changed demonstrated that for the lean air-fuel mixture which produces low NOx emission without EGR, the combustion phasing must be advanced to gain the better combustion efficiency at low load. By contrast, higher equivalence ratio allows the combustion phasing to be retarded with keeping high combustion efficiency. Copyright © 2007 SAE International.

DOI： 10.4271/2007-01-0053

相平衡理論およびソノケミストリーを用いた重質系燃料の改質に関する基礎的研究(第1報：燃料におけるソノケミストリー) 査読

花田俊一, 上田一生, 和田好充, 千田二郎, 渡辺好章

日本機械学会論文集(B編) 72 ( 724 ) 2984 - 2991 2006年12月

キャビテーション気泡の成長・崩壊を考慮した多成分燃料噴霧における微粒化過程のモデリング査読

和田好充, 千田二郎

日本機械学会論文集(B編) 72 ( 724 ) 3113 - 3120 2006年12月

燃料の物理・化学的特性を駆使した低環境負荷型圧縮着火燃焼に関する研究

小橋好充

同志社大学 2006年11月

Fuel Design Approach for Low Emission Spray Combustion by Use of Several Mixing Fuels 査読

Jiro Senda, KOBASHI, YOSHIMITSU, Daisuke Kawano, Hajime Fujimoto

Conference on Thermo-and fluid dynamic processes in Diesel Engines 297 - 308 2006年9月

ガソリン系燃料を用いた多段燃焼法の研究査読

原口茂則, 沖本和樹, 和田好充, 千田二郎, 藤本元

自動車技術会論文集 37 ( 5 ) 51 - 56 2006年9月

Cavitation Induced Breakup Model for Multi-Component Fuel Spray 査読

KOBASHI, YOSHIMITSU, Jiro Senda

International Conference on Liquid Atomization and Spray Systems, No.B4-05-106 1 - 8 2006年8月

An Experimental Study on Flash Boiling Spray using Two-Component Fuel under the Condition of Advanced Injection HCCI 査読

Yuji Nishimura, KOBASHI, YOSHIMITSU, Akihiro Yamaguchi, Jun-Kyu Yoon, Jiro Senda, Hajime Fujimoto

International Conference on Liquid Atomization and Spray Systems, No.D4-07-134 1 - 7 2006年8月

混合燃料の化学的性質と蒸発特性がディーゼル噴霧の自着火過程に及ぼす影響査読

和田好充, 橘田佳明, 山口晃弘, 西村優史, 千田二郎, 藤本元

日本機械学会論文集(B編) 72 ( 717 ) 1371 - 1377 2006年5月

A fundamental study on ignition characteristics of two-component fuel in a diesel spray 査読

Yoshimitsu Wada, Yoshiaki Kitta, Akihiro Yamaguchi, Yuji Nishimura, Jiro Senda, Hajime Fujimoto

SAE Technical Papers 1 - 10 2006年

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）

The authors have explored the potential of fuel to control spray and its combustion processes in a diesel engine. Fuel has some potential for low emission and high thermal efficiency because its volatility and ignitability are one of the ultimate performing factors of the engines. In present study, the ignition process of mixed fuel spray was investigated in a constant volume combustion vessel and in a rapid compression and expansion machine, The ignition delay based on the diagram of rate of the heat release, the imaging of natural flame emissions and the numerical simulation were carried out to clarify the effect of the physical and chemical properties of mixed fuel on ignition characteristics. Copyright © 2006 SAE International.

DOI： 10.4271/2006-01-3383

4814 キャビテーション気泡の成長・崩壊を考慮した多成分燃料噴霧の分裂モデル(S54-1 スプレーダイナミックス-計測とモデリング-(1),S54 スプレーダイナミックス-計測とモデリング-)

和田好充, 千田二郎

年次大会講演論文集 2006 329 - 330 2006年

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

A new primary breakup model of fuel spray with multi-component is proposed by considering the turbulent energy induced by the cavitation bubble. The model proposed here deals with bubble behavior inside nozzle, namely, the process of the growth, the shrinkage and the collapse processes are taken into account by applying Rayleigh-Plesset equation. The resultant energy contributes to the enhancement of initial perturbations on the spray surface and the perturbations grow under the action of aerodynamic force. The model proposed is implemented into KIVA-3V code in order to validate the effect of energy generated by the cavitation on the primary breakup of the discharging jet.

DOI： 10.1299/jsmemecjo.2006.3.0_329

4835 二成分混合燃料を用いたソノケミカル反応に関する基礎的解明(J10-4 次世代燃料及び潤滑油のためのエンジン適合技術(4),J10 次世代燃料及び潤滑油のためのエンジン適合技術)

上田一生, 和田好充, 千田二郎, 渡辺好章

年次大会講演論文集 2006 229 - 230 2006年

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, authors aim to convert heavy fuel or solid fuel into lighter liquid fuel with high quality and, authors propose fuel reformulation through sonochemistry and fuel design approach. Concept of Fuel design approach is to control fuel properties by mixing fuel. Its origin is Chemical-Thermodynamics and, heavy fuel converts into lighter fuel by it. The origin of sonochemistry is acoustic cavitation: creation, growth, implosive collapse of gas bubble by irradiation of high intensity ultrasonic. The sonochemical effect on organic liquid causes cleavage of C-C bond by hot spot conditions (more than 5000[K] and 100[MPa]) that are generated in collapse. In this paper, sonochemical reaction of mixing fuel was analyzed for ultrasonic of 20[kHz] and its result shows interaction of each components by fuel design approach with sonochemistry approach.

DOI： 10.1299/jsmemecjo.2006.7.0_229

3116 ディーゼル雰囲気場における二成分混合燃料の着火特性(S46-1 着火と燃焼の基礎,S46 着火と燃焼)

山口晃弘, 和田好充, 西村優史, 千田二郎, 藤本元

年次大会講演論文集 2005 69 - 70 2005年

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 the present study, we have proposed a novel fuel design concept in order to achieve low emissions and combustion control in diesel engine systems. According to the fuel design concept proposed in this work, the characteristics of vaporization during mixture formation process as well as of combustion can be reasonably improved due to the formation of two-phase region. Although some potential exits in this approach because spray and combustion phenomena are initiated by fuel, few studies similar to this research have been conducted. In this paper, the ignition characteristics of mixed fuel were investigated through a constant volume vessel and analysis of results shows the physical and chemical effect of each component consisted in mixed fuel on ignition processes.

DOI： 10.1299/jsmemecjo.2005.3.0_69

低エミッション・燃焼制御のための燃料設計コンセプト(第4報)－混合燃料の燃焼・排気特性－査読

川野大輔, 和田好充, 島田敦史, 千田二郎, 藤本元, 後藤雄一, 小高松男, 石井泰, 鈴木央一

自動車技術会論文集 35 ( 1 ) 63 - 68 2004年1月

各種混合燃料を用いたディーゼル噴霧の着火特性に関する基礎的研究(エンジンと新燃料(2),エンジンと新燃料)

和田好充, 橘田佳明, 山口晃弘, 千田二郎, 藤本元

年次大会講演論文集 2004 73 - 74 2004年

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

We have proposed a conceptual research with fuel approach to develop understanding for potential use of fuels in terms of further improvement of thermal efficiency and exhaust emissions because they provide the significant effect on diesel engine performance. As a result, we could conclude that mixing of high volatile fuel into low volatile fuel has a possibility to control the spray and combustion processes. However, for instance, high volatility component has low ignitability, which leads to longer ignition delay, with regard to straight-chain alkane. Thus, understanding the ignition behavior of mixed fuel consisting of high and low ignitability fuels is of particular importance as ignition delay dominates the combustion process related to exhaust emissions and thermal efficiency. In this paper, an ignition experiment was conducted to investigate the ignition characteristics of mixed fuel. The experiment includes the measurement of pressure waveform and CH chemiluminescence, which indicates the onset of heat release, in order to discuss about ignition processes of mixed fuel. The results provided conclusions that the ignition of mixed fuel was initiated by high ignitability fuel and affected by volatility of high ignitability fuel.

DOI： 10.1299/jsmemecjo.2004.3.0_73

Exhaust emission through diesel combustion of mixed fuel oil composed of fuel with high volatility and that with low volatility 査読

H. Fujimoto, J. Senda, D. Kawano, Y. Wada

SAE Technical Papers CD-ROM 2004年

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）

The mixed fuel composed of two kinds of fuel oil whose boiling temperature is different each other forms the fine spray with minute droplets when its condition crosses over the two-phase region. It is expected that the fuel with low volatility dominates the ignition delay and that with high volatility does the generation of particulate matter. The experiments were carried out in a rapid compression and expansion machine and in an actual high-speed small sized diesel engine by use of this kind of fuel. The experimental results prove this expectation. Copyright © 2004 SAE International.

DOI： 10.4271/2004-01-1845

多成分燃料噴霧における蒸発過程のモデリング査読

川野大輔, 千田二郎, 和田好充, 藤本元, 石井素, 鈴木央一, 後藤雄一, 小高松男

日本機械学会論文集(B編) 70 ( 696 ) 2213 - 2219 2004年

Fuel design concept for low emission in engine systems 4th report: Effect of spray characteristics of mixed fuel on exhaust concentrations in diesel engine 査読

Daisuke Kawano, Jiro Senda, Yoshimitsu Wada, Hajime Fujimoto

SAE Technical Papers 1 - 10 2003年

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）

In this study, the novel fuel design concept has been proposed in order to realize the low emission and combustion control in engine systems. In this fuel design concept, the mixed fuels with a high volatility fuel (gasoline or gaseous fuel components) and a low volatility fuel (gas oil or fuel oil components) are used in order to improve the spray characteristics by flash boiling. In our previous papers on this study, the fundamental characteristics of spray and its combustion of mixed fuel were reported. In this paper, heat release and exhaust emission (smoke, NOx and THC) characteristics of single cylinder diesel engine operated with the mixed fuels were investigated under each load. The exhaust performance of diesel engine could be improved using mixed fuel, because fuel properties and spray characteristics were controlled by changing mixing fraction of the mixed fuel. Moreover, in this exhaust gas concentration measurement, initial fuel temperature was employed for experimental parameter in order to control flash boiling process in mixed fuel spray, for flash boiling can be easily occurred by increasing initial fuel temperature. As a preliminary investigation of the flash boiling effect, the spray experiment for mixed fuel was conducted using constant volume vessel. As a result, it was confirmed that flash boiling had the potential of drastic reduction of smoke emission since flash boiling improved the atomization and vaporization of mixed fuel spray with rapid fuel-air mixing. Copyright © 2003 SAE International.

DOI： 10.4271/2003-01-1038

Numerical simulation of multicomponent fuel spray 査読

Daisuke Kawano, Jiro Senda, Yoshimitsu Wada, Hajime Fujimoto, Yuichi Goto, Matsuo Odaka, Hajime Ishii, Hisakazu Suzuki

SAE Technical Papers 2003年

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）

Fuel design for internal combustion engines has been proposed in our study. In this concept, the multicomponent fuel with high and low volatility fuels are used in order to control the spray and combustion processes in internal combustion engine. Therefore, it is necessary to understand the spray and combustion characteristics of the multicomponent fuels in detail. In the present study, the modeling of multicomponent spray vaporization was conducted using KIVA3V code. The physical fuel properties of multicomponent fuel were estimated using the source code of NIST Mixture Property Database. Peng-Robinson equation of state and fugacity calculation were applied to the estimation of liquid-vapor equilibrium in order to take account for non-ideal vaporization process. Two-zone model in which fuel droplet was divided into droplet surface and inner core was introduced in order to simply consider the temperature distribution in fuel droplet. Furthermore, droplet diameter after breakup was optimized by changing the parameters in original TAB model, because original TAB model underestimated a droplet diameter. The effects of fuel composition and initial fuel temperature on spray tip penetration, liquid droplet and vapor distribution, vapor mass and evaporation rate were investigated by using the multicomponent fuel spray model composed of these above sub models. From the numerical results, it was confirmed that the spray characteristics of multicomponent fuel drastically varied with a change in mixing fraction in multicomponent fuel and initial fuel temperature. Copyright © 2003 Society of Automotive Engineers, Inc.

DOI： 10.4271/2003-01-1838