研究者詳細 - 小橋　好充

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