基于分布函数预测-修正的LBM曲边边界处理新方法

A novel lattice Boltzmann model based on distribution function prediction-correction for treating curved boundary

该文提出了一个格子Boltzmann方法(LBM)下处理曲边边界的新格式。该方法先由一阶外推预测出边界点的分布函数,进而根据非平衡态外推得到壁面点的分布函数,最后应用壁面点和反向外推流场点的分布函数内插值对边界点的分布函数进行修正,统一了插值格式且精确实现了曲边无滑移边界条件。采用该方法对圆柱绕流、旋转、涡激振动(VIV)等问题进行了数值模拟,计算结果证明了该方法的准确性和有效性,且证实了该方法可以用于运动边界问题中新产生的流场点的分布函数计算。

In this paper, a new lattice Boltzmann method in non-slip boundary condition is proposed aimed to handle the curved boundary condition. The method is first to predict distribution function （DF） for the boundary nodes by a first order extrapolation, and then DF of the wall nodes is obtained using the non-equilibrium extrapolation, finally the predicted DF is corrected by interpolating the DF of the wall nodes and the corresponding extrapolated flow nodes. The interpolation form is unified and the non-slip curved boundary condition is achieved exactly. The present method is applied to simulate the problems of flow around a static, a rotational and a VIV circular cylinder. Calculation results are in good agreement with other findings and manifest the veracity and effectiveness of current method. And it is found that this method can also be applied to the DF calculation of new flow nodes from the moving boundary problems.