采用扩散信息保存(diffusive information preservation,D—IP)方法计算了雷诺数为10^2-10^4的二维方腔流动.D—IP方法是一种基于扩散运动观点的分子模拟方法,克服了经典直接模拟蒙特卡罗方法对于时间步长和网格大小的严格限制.在计算中,D—IP方法的时间步长和网格大小分别为分子平均碰撞时间和平均自由程的几十倍乃至几百倍,所得到的方腔流线分布和旋涡的精细结构,均与Navier-Stokes方程数值解相符.
Cavity flow is simulated using the diffusive information preservation (D-IP) method. The D-IP method is a molecular simulation scheme based on a viewpoint of molecular diffusion, and it greatly releases the time step and cell size limitations of the DSMC method that become too strict to meet as the Reynolds number increases. The Reynolds number in the present calculations ranges from 102 to 104, while the time step and cell size of D-IP are tens of times or even hundreds of times more than the molecular mean collision time and mean free path, respectively. The stream-wise distributions, as well as the fine structures of vortices, obtained by the D-IP method, are compared with the numerical solutions of the Navier-Stokes equations and found to be in good agreement.