二维卡门涡街的格子Boltzmann仿真

SIMULATING VORTEX FLOWS WITH LATTICE BGK MODEL

格子气自动机和格子Boltzmann方法的迅速发展提供了一类求解流体力学问题的新的方法。本文中，我们介绍了Boltzmann方法，解决了格子气方法中的缺点，通过选择适当平衡分布及其参数，导出了Navier－Stokers方程，并得到了声速和粘性系数。最后在微机上模拟了在无限长平板流动问题及绕单分离板的流动问题，得到了卡门涡街。结果表该模型有格子气方法及其它的数值方法所没有的优点，计算更精确、更直观、更有效。

The recent development of lattice gas automata and Lattice Boltzmann method have provided new computational models for solving a class of mathematical physic problems.In this paper, lattice boltzmann method is introduced here and it solved the shortcomings o f the lattice gas method. By choosing the parameters of the functions of the equilibrium distribution appropriately. we derive the Navier-Stokes equations, and we are able to obtain the sound speed, kinematic viscosity and bulk viscosity. At the end of this papert the computer simulated results of the laminar flow and vortex flow by this method coincide with the numerical results by Navier-Stokes equations. The numerical results show that the new method is efficient to solute Navier-Stokes equations and has great prospects.