基于AMESim软件的汽油机进气歧管和气门正时优化

摘要

In order to acquire lower fuel consumption and higher torque output at low and middle speed, an engine cycle simulation of a small turbocharged gasoline engine is conducted by AMESim. After validated against test data, the simulation model is used to optimize the full load performance of spark ignition(SI) engine. The effects of both intake manifold length and valve timing on the torque, volumetric efficiency and fuel consumption are investigated in details. To overcome the conflicts between low speed and high speed engine performance, variable valve timing(VVT) strategy is also investigated. The results show that, engine torque and brake specific fuel consumption(BSFC) during low and middle speed period can be improved effectively as valve timing is optimized and matched with intake manifold length reasonably using the gas dynamic effect.%　　为满足中低速较低油耗和较高扭矩输出，用AMESim软件对某小型涡轮增压汽油机进行了一维热力学过程仿真。在对仿真模型标定后，对所研究发动机的全负荷性能进行了优化。对进气歧管长度、气门正时对扭矩、充气效率和油耗的影响进行了计算分析。为克服高速和低速之间的矛盾，对采用可变气门正时策略进行了分析。结果显示，利用进气谐振效应合理地匹配进气歧管长度并对气门正时优化后，发动机中低速端扭矩和燃油消耗率都得到有效改善。