气门升程调节对发动机缸内流场的影响

Effects of valve lift adjustment on the flow field in the engine cylinder

发动机功率由进气量、气缸内的气流运动以及燃烧质量决定,可变升程也可以通过改善这几个方面来达到提高发动机性能的目的。所以主要研究了不同工况下的升程调节对发动机缸内流场的影响,通过采用Fluent建立进气道-气门-气缸三维瞬态CFD模型,对发动机转速为2 000 r/min时两种气门升程模式下的两种调节情况进行了速度场的模拟计算。最后对计算结果进行对比分析,得出了气门升程模式2优于气门升程模式1的结论。

Engine power is determined by air intake,airflow inside the cylinder and combustion quality,and through improving these aspects,variable lift can improve engine performance. In this study,we analyzed the effects of lift adjustment on the flow field in the engine cylinder under different working conditions. We established a duct- valve- cylinder transient state CFD model using Fluent,and carried out simulated calculation of the velocity fields under two different valve lift modes at an engine speed of 2000 r / min. In conclusion,valve lift mode 2 was proved to be better than valve lift mode 1.