用格子Boltzmann方法模拟圆柱绕流的振荡边界层

提出了一种用于模拟圆柱绕流的振荡边界层流动的新方法——旋转系统平均法。该系综由一些相同的系统组成,每个系统除使用不同的网格外,具有相同的流动。经模拟圆柱绕流的振荡边界层发现,流体质点的流动具有平行于振荡方向离开圆柱、竖直于振荡方向流向圆柱的特点,同时也发现在紧邻圆柱出现的被称为二次流的4个涡旋流动现象。数值模拟结果符合经典的理论结果。该方法也可用于其他圆柱绕流问题。

Lattice Boltzmann method for oscillatory boundary layer of circular cylinder flow

A new method, rotation-assemble-average method, for the oscillatory boundary layer flow around a circular cylinder, was proposed. This rotation assemble is consist of same systems and same flows except used different lattice grids. By simulating the oscillatory boundary layer flow around a circular cylinder, it was found that fluid particles movement along the direction of getting away the circular cylinder in the parallel direction of oscillatory, the fluid particles movement along to the circular cylinder in the vertical direction, and the second flow phenomenon with four vertexes near the circular cylinder in the same time. The numerical results agree with classical theoretical results. This method can be used to other problems of flows around circular cylinder.