不同湍流模型在列车外流场计算中的比较

A Comparative Study of Different Turbulence Models in Computation of Flow Around Simplified Train

摘要:

通过对简化缩比的列车模型在无侧偏角工况下分别进行模型风洞试验和数值模拟，评估了5种常用湍流模型在列车外流场模拟中的计算精度.数值模拟与风洞试验结果的分析对比表明： Realizable（可实现） k ε在阻力的计算上精度最高,误差最小为2.5%；SST（剪切应力输运） k w在升力的计算上更为精确，误差最小为0.5%.Standard（标准） k w和SST k w对准二维分离的捕捉与油流显示试验最接近，Realizable k ε则对三维分离位置的预测更准确.

Abstract:

An evaluation of the most frequenytly used five turbulence models on the flow around a simplified train model is presented. Based on numerical simulation and test results, a conclusion can be drawn that the most accurate prediction for drag is achieved by Realizable k ε, the minimum error is 2.5%, while shear stress transport(SST) k w is more accurate for lift, 0.5% is the minimum error. In addition, quasi two dimensional separation captured by Standard k w and SST k w approximates oil flow visualization, however, the three dimension separation is more exactly captured by Realizable k ε Model.