直角和贴体坐标系下两种格子Boltzmann方法的比较研究

采用格子Boltzmann方法(LBM)和改进的插值格子Boltzmann方法(GILBM)研究了45°斜方腔的顶盖驱动流和Roach通道内的流动特性,并与基准解进行了对比。结果表明,对于45°斜方腔的顶盖驱动流,当雷诺数较小时,两种方法的计算结果与基准解吻合较好;但当雷诺数较大时,采用LBM的计算结果准确性降低,而基于GILBM方法得到的结果准确度升高,且计算稳定性好。对于Roach通道内的流体流动而言,两种方法的计算精度和复杂边界的复杂程度与雷诺数大小有关。根据流场边界形状的复杂程度,网格划分与计算精确度的不同要求,两种方法各有利弊。

Comparison of two lattice Boltzmann schemes in cartesian coordinate and body-fitted coordinate system

In this paper,Lattice Boltzmann Method (LBM) and generalized form of interpolation lattice Boltzmann method (GILBM) are applied to study the inclined cavity with a tilt angle of 45° lid-driven flow and fluid flow characteristics in Roach channel.The simulations are compared with the benchmark solutions.It is found out that for the inclined cavity with a tilt angle of 45° lid-driven flow,when the Reynolds number is small,the results obtained from the two methods are in good agreement with the benchmark solution.As the Reynolds number increases,the accuracy of simulation based on LBM reduces,while the accuracy of the consequence obtained from GILBM rises with good stability.In terms of fluid flow in the Roach channel,the accuracy of the two methods is related to complexity of the boundary and Reynolds number.According to the different requirements of the complexity of the boundary shape,meshing and accuracy,the two methods have some advantages and disadvantages respectively.