四变量气门执行机构可控自燃汽油机稳态性能及过渡过程

利用一维循环模拟软件GT-Power,在Matlab-Simulink环境中建立了带有进、排气门升程及定时都可调节的四变量气门执行机构(4VVAS)的汽油机可控自燃(CAI)燃烧仿真试验平台,对不同气门参数下4VVAS-CAI汽油机的稳态性能和过渡过程进行了预测和试验验证.研究表明,在4VVAS-CAI汽油机稳态运行过程中,不同的气门运动规律组合方式可以取得相同的汽油机负荷,但指示燃油耗(ISFC)不同.着火时刻是影响ISFC的关键因素,而在着火时刻相差不大时,进气回流和泵吸损失是影响ISFC的主要因素.在过渡过程中,合理地同时调节4VVAS的气门升程和定时更有助于实现汽油机负荷的快速过渡.

Stable Performance and Transition Process of 4VVAS-CAI Gasoline Engine

A gasoline engine simulation panel with 4-variable valve actuating system(4VVAS) was established based on 1-D engine cycle simulation software GTPower and Matlab-Simulink.And the stable performance and transition process of 4VVAS-controlled auto ignition(CAI) gasoline engine with various valve parameters were studied by both model and experiment.Results show that the same load can be obtained under various combinations of valve events with different indicated specific fuel consumption(ISFC).Ignition timing is the main factor which affects ISFC,and intake air backflow and pumping loss are the other two important factors while the ignition time varies little.During transition process,4VVAS facilitates load transition through simultaneous adjustments of valve lifts and timings.