Study on wall model for LES based on coherent structures in turbulence

在大涡模拟中，研究了具有涡旋结构的速度梯度张量归一化第二不变量--相干结构函数的统计特性。结果表明，对于湍流槽道流动和均匀各向同性湍流，该函数的平均值、方差和pdf与雷诺数无关，与壁面距离有关，可作为壁面模型的变量。

In LES of turbulence simulation, investigated were the statistical properties of a coherent structure function, which shows an eddy structure and is a normalized second invariant of velocity gradient tensor. It was found that for turbulent channel flows as well as homogeneous isotropic turbulence, the average, the variance, and pdf of the function are independent of Reynolds number, depend on the distance from a wall, and is available as a variable for a wall model.