家用轿车发动机实现汽油缸内直喷的计算研究

Numerical Simulation of the GDI In-cylinder Process for a Family Car Engine

汽油缸内直喷 (GDI)已成为新一代汽油机提高经济性、降低排放的重要手段。作者以一台家用轿车三缸发动机为对象 ,对缸内直喷的空气流动、混合过程和燃烧情况进行三维模拟计算分析。结果表明 ,采用该燃烧室设计方案并与适当的喷雾、气流运动相配合 ,在当量燃空比时 ,使用汽油缸内直喷能获得与均质预混燃烧相近的效果。同时 ,通过调整喷油定时 ,能够在缸内形成工质的非均匀分布 ,在总空燃比为

The Gasoline direct injection (GDI) has become an important means to improve the economical performance and decrease the emission level of coming gasoline engines. In this paper, the airflow, mixing and combustion processes of a family 3-cylinder car engine with GDI were studied by means of the three-dimensional numerical simulation method. The result shows that after applying the design of such combustion system and adopting suitable spray timing and gas motion, in the case of combustion with mixture equivalent air/fuel ratio, the result is similar with that of homogeneous premixed combustion. While under the condition of total air/fuel ratio near 30, lean burn can be obtained by adjusting the injection timing to achieve non-uniform in-cylinder mixture.