Maxwell气固相互作用模型对稀薄高超声速凹腔绕流流动特征和热环境的影响  

Effect of Maxwell gas-surface interaction models on flow characteristics and thermodynamic properties of rarefied hypersonic cavity flows

作　　者：靳旭红 黄飞[1,3] 程晓丽 苏鹏辉[1,3] JIN Xuhong;HUANG Fei;CHENG Xiaoli;SU Penghui(China Academy of Aerospace Aerodynamics,Beijing 100074,China;School of Aerospace,Tsinghua University,Beijing 100084,China;Laboratory of Aero-Thermal Protection Technology for Aerospace Vehicles(LAPTAV),China Aerospace Science and Technology Corporation(CASC),Beijing 100074,China)

机构地区：[1]中国航天空气动力技术研究院,北京100074 [2]清华大学航天航空学院,北京100084 [3]中国航天科技集团有限公司航天飞行器气动热防护实验室,北京100074

出　　处：《航空学报》2021年第3期162-172,共11页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(11902313)。

摘　　要：针对高空航天飞机等再入飞行器表面缺陷或防热瓦缝隙导致的局部压力过高和气动加热问题,采用直接模拟Monte Carlo(DSMC)方法研究了飞行高度为80km的稀薄流区高超声速凹腔绕流问题,考虑气固相互作用(GSI)模型对凹腔流场特征和表面压力、热流的影响。结果表明:稀薄流条件(80km)下,GSI为完全漫反射时,在凹腔前缘分离的剪切层再次附着在后缘,在凹腔内部形成一个充满腔体的单涡结构;随着GSI从完全漫反射向镜面反射变化,气体与凹腔表面之间的切向动量交换减弱,即黏性剪切作用减弱,外部气流被卷入凹腔的程度减弱,导致涡结构不断减小直至消失,凹腔底部逐渐出现所谓的"死水区"。与完全漫反射相比,镜面反射或近镜面反射会导致凹腔上游侧面的峰值压力和峰值热流以及下游侧面的峰值压力剧烈增大,在飞行器设计中,应特别留意上述表面的压力载荷和热载荷。To alleviate the high local pressure and heat loads caused by cavities or imperfections on hypersonic vehicle surfaces,we investigate rarefied hypersonic flows over cavities at an altitude of 80 km using the Direct Simulation Monte Carlo(DSMC),examining the effects of Gas-Surface Interaction(GSI)models on flow characteristics inside the cavity,surface pressure and heat flux over the cavity surfaces.Results show that,in the rarefied regime(80 km),one primary vortex is formed as a result of shear layer separation and reattachment.In addition,as the GSI changes from perfect diffuse reflections to pure specular reflections,the exchanges of momentum in the tangent direction between the incident gas molecules and the cavity surfaces weaken,i.e.the viscous shear effects are weakened,lessening the ability of the external gas to penetrate deeper into the cavity.Therefore,the vortex inside the cavity progressively diminishes till ultimately disappears,leaving behind a so-called"dead-water region"at the bottom of the cavity.In comparison with the perfect-diffuse case,pure or near specular reflection causes a significant increase in the peak pressure and heat flux on the front wall of the cavity,and the peak pressure on the aft wall.Therefore,much attention should be paid to the pressure and heat loads on the aforementioned surfaces in the aerodynamic design.

关 键 词：稀薄气体 气固相互作用 凹腔 高超声速 直接模拟Monte Carlo(DSMC) 

分 类 号：V411.3[航空宇航科学与技术—航空宇航推进理论与工程]