三效催化转化器压力损失对发动机性能的影响

采用计算流体动力学软件对三效催化转化器(TWC)流场和压力损失进行了数值模拟，并对原机与安装TWC后发动机的特性曲线进行了对比试验。结果表明：发动机的转速越高，即TWC的入口流速越大、流速分布越不均匀，压力损失越大；压力损失使发动机的排气背压升高，引起充气效率下降；高速时充气效果明显下降，发动机的动力性和燃油经济性降低。

A Study on the Effect of Pressure Loss in Three-way Catalytic Converter on Engine Performance

A computational fluid dynamics code was used to simulate the flow field and pressure loss in three-way catalytic converter(TWC),and a contrastive test for characteristic curves of the engines with and without TWC was performed.The results showed that the higher the engine speed,hence the higher the flow velocity in the inlet of TWC,the more uneven the flow velocity distribution,and the larger the pressure loss in catalytic converter.The pressure loss caused the increase in exhaust back pressure,leading to the decrease in charge efficiency.At high speed,the decrease in charge efficiency became more remarkable with power performance and fuel economy worsened.