An Alternative Scheme to Calculate the Strain Rate Tensor for the LES Applications in the LBM
An Alternative Scheme to Calculate the Strain Rate Tensor for the LES Applications in the LBM
复制标题
DOI：
10.1155/2010/724578
复制
发表时间：
2010-12
影响因子：
--
通讯作者：
Jun Li;Zhengwei Wang
中科院分区：
文献类型：
--
作者：
Jun Li;Zhengwei Wang
基于Smagorinsky模型的大涡模拟LES可以方便地用于格子Boltzmann方法LBM中，因为用于确定涡动粘度的应变率张量Sij可以从非平衡分布函数的二阶矩计算，并且可以显式地确定当前的总无量纲弛豫时间。本文提出了一种新的方法，其中松弛子程序后的分布函数与运动子程序后的分布函数不同，从而得到了一种类似的方法来确定Sij，但由于其隐含的特征，其应用是不方便的。然而，推导也导致了一个替代的显式计划计算Sij的基础上的物理分析的动量传输过程中，应力张量，Tij，首先计算，然后Sij确定从Tij使用的本构关系牛顿流体。当前的总无量纲弛豫时间也明确给出，使该LES模型可以很容易地使用在LBM。
Large eddy simulationsLESbased on the Smagorinsky model can be conveniently used in the lattice Boltzmann methodLBMbecause the strain rate tensor, Sij, used to determine the eddy kinematic viscosity can be calculated from the second-order moment of the nonequilibrium distribution function, and the current total nondimensional relaxation time can be determined explicitly. A new method is developed where the distribution function after the relaxation subroutine differs from that after the motion subroutine leading to a similar method to determine Sij, but its application is inconvenient due to the implicit feature. However, the derivation also leads to an alternative explicit scheme for calculating Sij based on physical analysis of the momentum transport process, where the stress tensor, Tij, is calculated first, and then Sij is determined from Tij using the constitutive relationship for Newtonian fluid. The current total nondimensional relaxation time is also given explicitly so that this LES model can be easily used in the LBM.