移动网格技术在计算流体动力学数值仿真中的应用

Research on the Application of Moving Mesh Technology in Computational Fluid Dynamics Simulation

基于调和映射理论,将移动网格技术(moving mesh technolog)应用到计算流体动力学(computational fluid dynamics,CFD)的数值仿真计算中。推导了移动网格技术在处理大变形问题时求解域的更新过程,并给出了相应的程序流程图,解决了传统固定网格无法模拟大变形的问题。利用多物理场耦合分析软件COMSOL Multiphysics 4.0a将移动网格方程与流体流动的控制微分方程耦合求解,模拟了油箱晃动时里面油的运动情况。数值模拟得出:移动网格技术可以较真实的模拟流体求解域的大变形问题;在仿真过程中,流体求解域范围内的节点和网格数量并没有增加,只是网格的形状发生了改变,因此移动网格方法并不会额外增加计算机资源。

This paper applies moving mesh technology to the numerical simulation analysis of computational fluid dynamics（CFD） based on harmonic mapping theory. It deduces renewal process of the solving domain when moving mesh technolog deals with problems of large deformation, and the corresponding program flow diagram is given. It solves the problems of grid large deformation which the traditional fixed grid is unable to simulate. It uses the multi-physical coupling analysis software COMSOL Multiphysics 4. 0a to couple the moving mesh equation with controlling differential equation,and simulates the movement of the oil inside the swaying tank. The numerical simulation show that moving mesh technology can simulate the situation of solving domain^s large deformation truly. In the process of simulation,the number of the nodes and grids in the fluid domain do not increase,it just changes the shape of the grids,so that,the moving mesh method dose not increase the spending of computer resources extra.