著者
西村 章広 脇坂 知行
出版者
The Japan Institute of Marine Engineering
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.40, no.2, pp.266-272, 2005-03-01 (Released:2010-05-31)
参考文献数
15

A diesel fuel breakup model was developed in the framework of the three-dimensional fluid dynamics code KIVA-3V and validated with experimental data. This breakup model accounts for cavitation bubble collapse energy, turbulent kinetic energy, and aerodynamic forces on the liquid core. The primary breakup time is computed by a balance between surface tension of the liquid core and the breakup forces obtained as aerodynamic force and breakup force based on cavitation bubble collapse. The calculated diameter of the child droplet is based on the liquid core surface wavelength, which is caused by fluctuating turbulence velocities. At the time of primary breakup, a child droplet uses its turbulent energy to determine the ensuing trajectory. Hence, the proposed Cavitation Bubble Collapse Energy Breakup (CEB) model is capable of predicting the spray cone angle. Generation of child droplets as a result of primary breakup continues until all cavitation bubbles have totally collapsed. Subsequently, the Taylor Analogy Breakup (TAB) model is used for secondary droplet breakup. Model predictions of spray tip penetration, spray cone angle, and Sauter Mean Diameter (SMD) have been found in good agreement with experimental data for non-evaporating sprays under high injection pressure.
著者
脇坂 知行 藤本 英史 松川 洋介 高田 洋吾
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.43, no.6, pp.971-976, 2008-11-01 (Released:2010-05-31)
参考文献数
10
被引用文献数
1

The purpose of this study is to establish a practical method based on a chemical kinetic model for three-dimensional numerical analysis of the combustion process in direct-injection diesel engines. For saving computational time, a reduced elementary reaction scheme for diesel fuel was constructed. The basis was the Golovitchev detailed elementary reaction scheme. Using an original engine combustion simulation code GTT-CHEM along with the reduced elementary reaction scheme, the combustion process was three-dimensionally analyzed in a direct-injection diesel engine with high-EGR ratios.As a result, the combustion process and NO emission were quantitatively predicted by estimating the initial gas state and the initial composition appropriately. The emission tendency of soot was reasonably assessed by means of φ-T maps.