动能BGK算法在近连续流模拟中的应用

首先比较详细地介绍了动能BGK算法的基本思想,然后应用该算法,数值模拟了克努森数(Knudsen number)为0.0001～1.56,马赫数为1.96绕圆柱的二维粘性流动,研究了滑移边界条件和无滑移边界条件对圆柱阻力的影响,通过与实验结果5]进行比较,验证了文献1]关于由连续流到自由分子流的这种流动模型的划分.计算结果表明:采用滑移边界条件,直到克努森数为0.3,计算得到的阻力与实验都符合得很好.因此,采用BGK算法加滑移边界条件,能够模拟由连续流到近连续区的流动.

Application of kinetic BGK algorithm in simulating near continuum flow

First, the kinetic BGK method is narrated in detail in this paper, then the viscous flows around the cylinder are numerically simulated using this method with slip boundary or no-slip boundary on the wall surface with Mach number at 1.96 and Knudsen number from 0.0001 to 1.56. Investigation of the influence of the slip boundary on the drag has been done by comparison the numerical results with the experimental data. The numerical results show that the kinetic BGK with slip boundary condition can obtain the drag coefficient, which is well agreement with the experimental data till Knudsen number up to 0.3, and can simulate the continuum-transition flow.