直喷汽油机闪急沸腾喷雾雾化机理研究

项目名称： 直喷汽油机闪急沸腾喷雾雾化机理研究

项目编号： No.51276127

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 能源与动力工程

项目作者： 王天友

作者单位： 天津大学

项目金额： 80万元

中文摘要： 闪急沸腾喷雾具有贯穿距短、喷雾锥角大、液滴粒径小的优良喷雾特性，可以显著改善直喷汽油机的燃烧及排放特性。本项目拟采用独创的高液滴数密度激光干涉粒子成像（IPI）结合激光粒子成像测速（PIV）技术，对汽油闪急沸腾喷雾的宏观形态、粒径分布、液滴及气体速度场进行深入的研究，全面掌握闪急沸腾喷雾的喷雾特性，力求揭示高过热度下闪急沸腾喷雾塌缩现象的发生机理，探明缸内气流运动对闪急沸腾喷雾雾化及混合气形成的影响规律。同时，采用直接数值模拟方法，研究过热液滴内部气泡成核及生长、液滴破碎及碰撞等微观过程，揭示液滴内部气泡对二次雾化过程的作用机理，并以此为依据完善闪急沸腾喷雾相关雾化子模型。在此基础上，首次将闪急沸腾喷雾实际应用于直喷汽油机中，寻求改善直喷汽油机燃烧及排放特性的最佳途径。本项目的研究对于丰富和完善喷雾雾化理论具有重要的意义，并将对直喷汽油机技术的发展产生深远的影响。

中文关键词： 直喷汽油机；闪急沸腾喷雾；雾化机理；激光干涉粒子成像；数值模拟

英文摘要： With the fine characters of short penetration, large spray angle and small droplet size distribution, flash boiling spray can be employed to improve the combustion process of gasoline direct injection engines significantly. In the present project, using high droplet number density interferometer particle imaging (IPI) combined with particle image velocimetry (PIV) technology, it is planned to conduct in-depth investigation on the droplet size distribution, droplet velocity field and gas velocity field of gasoline flash boiling spray, to fully grasp the characteristics of gasoline flash boiling spray, to reveal the spray collapse mechanism at high superheat degree, and to detect the effect of in-cylinder flow on spray and mixture formation. Through direct numerical simulation on the bubble formation, bubble growth, droplet breakup and droplet collision processes,it is expected to reveal the effect of contained bubble on the secondary atomization process, and finally improve the existing flash boiling spray atomization sub-models. On this basis, it is supposed to improve the combustion and emission characteristics of gasoline direct injection engine by using flash boiling spray for the first time. The present study is of great significance on the spray atomization theory, and will have a profound impact on the dev

英文关键词： Gasoline direct injection engine；Flash boiling spray；Atomization mechanism；Interferometric particle imaging；Numerical simulation