THE NUMERICAL STUDY OF LATTICE BOLTZMANN METHOD BASED ON DIFFERENT GRID STRUCTURE

In this paper, we mainly focus on the different grid structures used in lattice Boltzmann method (LBM). We present corresponding methods for each grid structure. As we know, in the numerical simulations based on the traditional LBM, the standard uniform grid is always hired. This is up to the discrete velocities on the grid node. Yet, it is a thorny question when the LBM is employed to solving problems with complex boundaries, due to the grid structure of standard uniform grid itself. And this shortcoming would decrease the applicability of LBM. Besides, for those complicated flows, it is necessary to have enough meshes to capture the flow information in the zones where the flow state changes fiercely. In another word, if there are too many grids, it will greatly enlarge the computational burden with the use of standard uniform grid. On the other side, if the grids are not enough, it is hard to get a satisfied result. This dilemma greatly decreases the efficiency of LBM. For solving those questions above, we use different grid structures to improve the applicability and efficiency of LBM. In this paper, we perform the simulations of the lid-driven flow of cavity, flow around cylinder and flow around airfoil as our numerical cases.