再入飞行器鼻锥逆向喷流对流场及气动热的影响  

Influence of Opposing Jet on Flow Field and Aerodynamic Heating at Nose of a Reentry Vehicle

作　　者：戎宜生[1] 刘伟强[1] 

机构地区：[1]国防科学技术大学航天与材料工程学院,湖南长沙410073

出　　处：《航空学报》2010年第8期1552-1557,共6页Acta Aeronautica et Astronautica Sinica

基　　金：高等学校博士学科点专项科研基金(200899980006);湖南省自然科学基金(09JJ3109)

摘　　要：使用计算流体力学(CFD)方法研究逆向喷流热防护系统对降低再入飞行器鼻锥物面热流的效果,获得了流场参数,回流再附点位置,物面压力分布以及热流分布。分析了逆向喷流对降低物面热流的物理机理,喷流通过与来流相互作用形成马赫盘,将来流导流到四周,不与物面直接作用形成气动加热,同时喷流回流形成低温区,降低物面与接触气体的温差,进而降低了物面热流。随着总压比率增大,这种效果越明显,气动加热越轻。为更合理分析喷流强度对流场及传热量的影响,将总压比率和流量相结合,提出了新的参数RPA。分析该参数的应用效果,结果发现不同的流量与总压比率组合成相同的参数RPA,可以实现相同的激波位置、再附点位置、表面热流峰值位置和总传热量。这说明该参数可用于表征喷流强度,用以分析喷流对流场及传热量的影响。A CFD study on the reduction of aerodynamic heating on the nose of a reentry vehicle by an opposing jet thermal protection system is conducted,by means of which the flow field parameters,reattachment point position,surface pressure distribution and heat flux distribution are obtained.The physical mechanism of the reduction of heat flux is analyzed.The opposing jet interacts with the freestream to form a Mach disk which enables the freestream to flow to the edges rather than interact with the surface to produce aerodynamic heating.In addition,the jet flows back to form a cool recirculation region,which reduces the difference in temperature between the surface and the nearby gas,and thus reduces the heat flux.The larger the total pressure ratio,the lower is the aerodynamic heating.To study the effect of the intensity of the opposing jet more appropriately,a new parameter RPA is defined by combining the flux and the total pressure ratio.The study shows that the same shock wave position,reattachment point position,peak heat flux position and total heat load can be obtained with the same RPA with different fluxes and total pressure ratios,which means the new ratio parameter may account for the intensity of the opposing jet and be used to analyze its influence on the flow field and total heat load at the nose of a reentry vehicle.

关 键 词：逆向喷流 气动加热 总压比率 流量 热防护系统 

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]