三叶片节气门与传统节气门发动机缸内流场仿真

Simulation of the in-cylinder Flow Field of the Engine with Tri-blades Throttle and Conventional Butterfly Throttle

对低气门升程下搭配有传统节气门、三叶片节气门的发动机进行台架试验,并得到了其对应的发动机万有特性图。通过建立发动机从节气门至气缸内的模型,选择目标工况点,在FLUENT里面进行了对比计算。结果表明,发动机中速高负荷时,搭载三叶片节气门的发动机比搭载传统节气门的发动机具有明显较优的缸内涡流强度、滚流强度以及湍动能,从而解释了搭载三叶片发动机的万有特性图中中速高负荷区域具有较好燃油经济性的原因。

Engine bench tests have been proceeded both on the engine equipped with conven- tional butterfly throttle and tri-blades throttle and the universal characteristics of engine has been mapped. By modeling the entire engine intake system, including the throttle, intake manifold, intake valves and cylinders, comparing the results using FLUENT, it turns out that during the medium speed- high load working conditions, engine with tri-blades throttle can producing more intense swirl, tumble and turbulence. Thus why the engine with tri-blades throttle is more economy during medium-high load operating conditions is explained.