气体稀薄效应对热流计算的影响  

Influence of rarefied gas effect on the computation of heat flux

作　　者：陈杰 张家骐 欧吉辉 CHEN Jie;ZHANG Jiaqi;OU Jihui(Laboratory for High Speed Aerodynamics,School of Mechanical Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学机械工程学院高速空气动力学研究室

出　　处：《空气动力学学报》2019年第5期691-697,共7页Acta Aerodynamica Sinica

基　　金：国家自然科学基金(11802202,11732011)

摘　　要：临近空间高超声速飞行器的研发越来越受到关注。周恒和张涵信在《中国科学》上的《空气动力学的新问题》一文中分析了在此情况下现有的空气动力学的不足,其中之一就是需要考虑流场中可能出现的局部稀薄气体效应,并且针对临近空间高超声速飞行器边界层进行了详细的分析。陈杰和赵磊在此基础上研究了强剪切下的气体稀薄效应,给出了判别气体稀薄效应的无量纲参数 Zh ,并提出对传统连续介质模型中的黏性系数基于Zh参数进行修正。本文将通过类似的研究方法,采用DSMC (Direct Simulation Monte Carlo)研究纯导热问题中的气体稀薄效应,通过对粒子速度分布函数的分析提出了相应的刻画气体稀薄效应的参数Zh T,获得了依赖参数Zh T的导热系数修正规律,并进一步将该修正规律纳入CFD (Computational Fluid Dynamics)计算,验证了该算法对圆柱绕流问题表面热流预测的精度。Research and development of the technology for near space hypersonic flying vehicles have drawn more and more attention. In the article “New Problems of Aerodynamics”,Zhou and Zhang showed that,for near space flying vehicles,the existing aerodynamics is inadequate and one of the new problems is how to take the local rarefied gas effect into consideration. They also analysed hypersonic boundary layer of near space flying vehicles. Based on the research, Chen and Zhao studied the local rarefied gas effect for strong shear flow,and proposed a non-dimensional parameter Zh to characterize the rarefied gas effect. They indicate that the viscosity coefficient in conventional continuum model should be modified according to the value of Zh . In this paper,in a similar way,the rarefied gas effect in heat conduction problem is investigated by Direct Simulation Monte Carlo (DSMC). A characteristic parameter Zh T is proposed based on the analysis of the velocity distribution functions of molecules,and the correction on thermal conductivity depending on the parameter Zh T is obtained. A hypersonic flow of argon over a two dimensional cylinder is simulated by the proposed model,and the heat flux on the surface is examined.

关 键 词：稀薄气体效应 有效导热系数 热流计算 DSMC 

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]