大瑞利数下二维Benard对流演化过程的DSMC仿真研究  

Investigation of Benard convection flow under iarge Rayleigh numbers in rarefied gas by DSMC method

作　　者：张志成[1] 陈伟芳[1] 吴其芬[1] 彭威[2] 

机构地区：[1]国防科技大学航天与材料工程学院,长沙410073 [2]军械工程学院,石家庄050003

出　　处：《空气动力学学报》2002年第4期434-440,共7页Acta Aerodynamica Sinica

基　　金：国家自然科学基金资助项目;项目编号(19902021)

摘　　要：利用DSMC(DirectSimulationMonteCarlo)方法研究了大Rayleigh(瑞利)数条件下稀薄气体的二维Benard对流的特性。考察了流动的非定常演化过程及若干流动特征量随时间的变化特征,得到了与实验较为一致的结论。计算结果表明,当流动控制参数不断增大时,二维Benard对流从热传导状态过渡到热对流状态表现出明显的非定常演化特征。最后当瑞利数增大到一定程度后,流动显示出混沌的特征。The new properties of Benard convection flows under large Rayleigh numbers in rarefied gas are investigated by Direct Simulation Monte Carlo method. Special emphasis is placed on the unsteady development of the flow and some other physical properties. It is shown that with the Rayleigh number increasing, the Benard flows exhibit aunsteady transition from stable conduction state to convection state and when the Rayleigh number increase to certain critical number, the Benard convection system transforms to a flow with chaotic properties.

关 键 词：DSMC 稀薄气体 Benard对流 混沌 仿真 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]