Rayleigh-Benard系统不稳定性的DSMC方法研究(英文)

DSMC Study of Rayleigh-Benard Instabilities

本文应用DSMC方法初步研究了稀薄气体状态下Rayleigh-Benard系统的不稳定性特征,着重考察了气体密度梯度对Rayleigh-Benard系统不稳定性特征的影响。研究表明DSMC方法能够成功地模拟Rayleigh-Benard系统内涡的运动,得到了与外力方向相反的密度梯度会增加Rayleigh-Benard系统流动不稳定性的结果。

Direct simulation of Monte Carlo (DSMC) method has been applied to study the instability of Rayleigh-Benard (RB) system in rarefied gas. It shows that the DSMC method can successfully simulate the vortex motions in RB system. Special emphasis is put on the effects of the density gradient on the stability of the system. When the Boussinesq approximation is invalid, the numerical results show that the density gradient in the direction of the external force can make the onset of the RB instability occur at smaller Rayleigh number.