车用催化转化器流场的数值模拟

本文用当量连续法建立了蜂窝载体的流体力学模型 ,并用CFD软件对整个催化器的流场进行了稳态流动数值模拟。模拟结果显示 :气流在圆锥管壁面附近出现了分离并产生较强的扰动 ,造成气流局部压力损失和载体前气流速度分布不均匀 ;此外 ,扩张角越大 ,催化器流速分布不均匀性和压力损失越大 ,但当扩张角增大到一定程度后 ,扩张角对流速分布和压力损失的影响变小。

Numerical Simulation of Automotive Catalytic Converters

In this paper,a mathematical model of flows in the substrate was established using the equivalent continuum approach,and multi-dimensional numerical simulation of the steady flows in the catalytic converters was performed.Simulation results show that the separation and vortex,which cause the pressure loss and the velocity non-uniformity at the front of the first substrate,are generated near the wall of the conical pipe.In addition,the larger the inlet cone angle the more the pressure loss and maldistribution in converters,however,when the angle enlarges enough its effect on flows will be obviously decreased thereafter.