在用大涡模拟的方法计算具有强剪切的槽道湍流时,常用的亚格子应力模型,包括考虑壁面修正的模型,都会出现平均流剖面偏高的现象.这表明在壁面附近亚格子应力模型还不能描述实际情况.针对这一问题,修正了亚格子雷诺应力模型的壁面函数,得到了较好的计算结果.用修正后的模型计算出的平均速度分布、均方根速度的分布以及雷诺应力的分布,均与直接数值模拟(DNS)的结果吻合较好.
If large eddy simulation method is used to calculate the turbulent channel flow with strong shear, the commonly used sub-grid stress models, including wall modification model, will generate excessively high mean velocity profiles. It indicates that sub-grid stress model cannot describe the situation nearby the wall. To this end, the wall function of the sub-grid Reynolds stress model was modified to obtain a better result. The mean velocity profiles, the RMS(root-mean-square) velocity profiles and Reynolds stress profiles calculated by the modified model are consistent with the results of DNS.