增压汽油机水套流场结构分析及优化

Structure Analysis and Optimization for Cooling Jacket of Turbo Gasoline Engine

汽油机小型化、增压化增加了整机热负荷强度,对冷却水套的设计提出了更高的要求。在某增压汽油机水套开发过程中,探索了一些新的分析设计思路:从总体估计水套的流动趋势,识别流动关键流动通路;逐个单独连通关键缸垫上水口,通过考察水套流场,观测关键流动通路的流量分配,找出水套流场的规律;根据水套流场的规律,针对性地进行结构优化,调整关键流动通路的流量分配比例,使之趋于更均衡更合理。进行水套工况模拟及缸体缸盖热负荷模拟,通过水套表面HTC分布与缸体缸盖温度分布对比证明了水套优化及分析设计思路的合理性和有效性。

It is the trend of downsizing and enhancements for gasoline engine to increase thermal load on the engine body and raise higher requirement on cooling jacket. Some novel ideas are proposed during developing the cooling jacket of turbo engine： Firstly to take an overview on the flow trend of the jacket and to identify key path of the flow; Secondly to connect key water holes on the gasket individually to comprehend the features of the flow field in the cooling jacket by observing the flow distribution among key flow paths; Thirdly to make the purposeful optimization on the cooling jacket structure to make the flow distributions become balanced and satisfactory. Finally simulation on cooling jacket flow and engine body thermal load under working condition is performed and the reasonability and effectiveness of the proposal on cooling jacket analysis strategy are confirmed by comparing cooling jacket surface HTC and temperature of the engine body between the initial cooling jacket and the optimized one.