自然吸气缸内直喷汽油机气流运动的模拟分析

Simulation and Analysis on the Airflow of a NA GDI Engine

对一台自然吸气直喷汽油机考察了进气道的性能,模拟进气及压缩过程的气流运动,比较进气道与不同燃烧室匹配的效果。结果显示,在高流量系数、中等滚流比进气道的配合下,平顶活塞燃烧室在进气过程中形成的滚流更强,利于在进气初期喷油的均质燃烧;斜坑活塞燃烧室在压缩后期形成的滚流更强,利于在压缩过程喷油的分层燃烧。

Focus on a naturally aspirated gasoline direct injection engine,the performance of intake port is evaluated,the airflow of intake and compress processes is simulated,and the effects of different combustion chambers combinations with the intake port are compared.The results show that,combing with a high flow capacity and low tumble intake port,the tumble formed during intake has greater intensity with a flat piston,it does good for the homogeneous combustion which injection begins at the early intake process;a larger tumble is formed in the late compression process by a piston with combustion chamber,it will benefit to the stratified combustion which injection occurs in the compression process.