基于微分雷诺应力湍流模型的车辆气动特性的数值模拟

针对Ahmed标准汽车模型,采用含有二阶矩的微分雷诺应力模型(DRSM)对车辆外流场进行了数值模拟,对照风洞试验,获得了气动阻力系数以及3个尾流横截面中速度矢量分布等结果。参考RNGk-ε模型,对比分析了DRSM数值模拟的气动阻力系数与试验值之间的误差及误差产生原因。结果表明,DRSM模型在车辆外流场模拟中有更高的计算精度,可正确地获得包括车辆尾流中的二次流等在内的复杂气动特性。

Numerical simulation of vehicle aerodynamic characteristics based on DRSM

The differential Reynolds stress turbulence model(DRSM) with the second order moment closure was used to numerically simulate the external flow field around the Ahmed standard car model,and the aerodynamic drag coefficient and the velocity vector distributions in the 3 sections of the wake were obtained by comparison between the simulation result and the corresponding wind tunnel experimental data.The differences among the drag coeffcients from the RNG k-ε model simulation,the DRSM simulation and the experiment were discussed,which revealed that the DRSM model is characterized by higher computation accuracy than RNG k-ε model,can provide correctly the vehicle aerodynamic characteristics including the second flow in the vehicle wake.