配气相位对汽油机动力性影响的仿真研究

Simulation studies of the influence of gas distribution phase on the dynamics of gasoline engine

基于AVLBOOST软件对某轻型车用废气涡轮增压GDI发动机的工作过程进行模拟仿真,并使用台架实验数据对模型进行了验证。在此基础上进行发动机配气相位的优化工作,得到全负荷与部分负荷工况时不同转速下发动机动力性能随配气相位的变化规律:适当增大进气提前角可以提高发动机低转速下的输出扭矩并提高动力性,增大进气迟闭角会导致输出扭矩的降低与动力性的恶化,改变排气相位均会导致全转速下输出扭矩的减少,经过分析后求得最佳的配气相位。仿真结果表明,优化后的配气相位令发动机低转速下输出扭矩及整体扭矩储备系数显著增大,工作更为稳定,动力性提升明显。

Based on AVL BOOST software,the working process of a light-duty exhaust gas turbocharged GDI engine was simulated,and the model was verified by using the bench experimental data.Thenthe engine′s valve timing optimization was carried out.The law of change of the engine′s dynamic performance with valve timing at different speeds under full-load and partial-load conditions was analyzed.That is,appropriate increase of intake advance angle can improve the output torque at a low engine′s speed and the engine′s dynamic performance,increasing intake retard angle will cause decrease of the output torque and deterioration of the engine′s dynamic performance.Changing exhaust valve timing will result in reduction of the output torque at all rotational speeds.After the analysis,the optimal valve timing was obtained.The simulation results show that the optimized valve timing makes the output torque of low engine′s speeds and the overall torque reserve coefficient significantly increase.The operation stability and dynamic performance can also be greatly improved.