汽车排气系统总成的计算流体力学模拟

Simulation of Computational Fluid Dynamics in Vehicle Exhaust System

汽车排气系统采用数值模拟的方法较传统的试验方法省时、省力,且节省试验费用,文章利用通用流体力学软件对排气系统总成的流场和温度场进行了深入的模拟研究,得到了排气系统的总背压随转速变化曲线;详细分析了紧耦合催化器和前后消声器的流场特征,得出了产生背压的主要部件是后消声器。同时表明,三维CFD模拟技术在汽车排气系统中的应用为汽车排气系统设计提供新的理念和方法。

Using numerical simulation in vehicle exhaust system is time saving, effort saving and test cost saving than traditional test method. The flow field and the temperature field of exhaust system is studied in detail by CFD simulation in this paper. The back pressure at different rev is obtained. The flow characteristics of the close coupling catalytic converter, the front muffler and the rear muffler are analyzed. Basing on this analysis, it is concluded that the main drop of pressure takes place in the rear muffler. At the same time it is indicated that the application of three-dimensional CFD simulation in vehicle exhaust system provides new design concept and method.