V字形钝前缘激波反射迟滞现象  

Shock Reflection Hysteresis Phenomena on V‑shaped Blunt Leading Edges

作　　者：王军 张志雨 刘愿[2] 钱战森[2] 李祝飞[1] WANG Jun;ZHANG Zhiyu;LIU Yuan;QIAN Zhansen;LI Zhufei(Department of Modern Mechanics,University of Science and Technology of China,Hefei 230027,China;AVIC Aerodynamics Research Institute,Shenyang 110034,China)

机构地区：[1]中国科学技术大学近代力学系,合肥230027 [2]中国航空工业空气动力研究院,沈阳110034

出　　处：《南京航空航天大学学报》2022年第4期564-572,共9页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：国家自然科学基金(12172354,11772325,11621202)。

摘　　要：针对内转式进气道唇口在宽速域条件下面临的复杂激波干扰问题,将唇口模化为V字形钝前缘,采用数值模拟并辅以风洞实验,研究了典型V字形构型(根部倒圆半径R与前缘钝化半径r之比R/r=1,半扩张角β=18°)激波反射结构随来流马赫数Ma_(∞)的演变过程。结果表明,随着Ma_(∞)的增大或减小,V字形后掠前缘的脱体激波产生规则反射(Regular reflection,RR)和马赫反射(Mach reflection,MR),并且两者的相互转变过程出现迟滞。初场为RR时,V字形根部产生大范围的流动分离和分离激波;随着Ma_(∞)由5.7逐渐增大至6.5,脱体激波的交点向下游移动并与分离激波的交点重合,使RR转变为MR。初场为MR时,马赫杆下游存在大尺度的反转涡对;随着Ma_(∞)由6.7逐渐减小至5.9,反转涡对不再影响脱体激波,使MR转变为RR。通过Ma_(∞)=6的风洞实验证实,在相同来流条件下存在RR和MR双解。基于对脱体激波交点、分离激波交点和反转涡对尺度随Ma_(∞)变化规律的认识,建立了RR↔MR的转变边界。在双解区中,RR工况的壁面压力最大值约为MR工况的2~3倍,表明迟滞现象将导致唇口气动载荷突变。Three-dimensional shock interactions are commonly encountered on the V-shaped cowl lips of inward-turning inlets in the wide-speed range flight.The evolution of shock reflections on a V-shaped blunt leading edge(the crotch radius over the leading-edge radius R/r=1,the half-span angleβ=18°)with the variation of freestream Mach number(Ma_(∞))is investigated using numerical simulations methods and wind tunnel experiments.The results indicate that the interactions between the detached shocks on the two swept branches can generate both regular reflection(RR)and Mach reflection(MR).A hysteresis appears in the transition between RR and MR depending on the increase or decrease in Ma_(∞).When the initial reflection type is RR,large-scale flow separations and separation shocks occurs at the crotch.With Ma_(∞)increasing from 5.7 to 6.5,the intersection point between the detached shocks moves downstream and coincides with the intersection point between the separation shocks,which causes the transition from RR to MR.When the initial reflection type is MR,a large-scale counter-rotating vortex pair occurs at the downstream of Mach stem.With Ma_(∞)decreasing from 6.7 to 5.9,the counter-rotating vortex pair no longer affect the detached shocks,which causes the transition from MR to RR.A wind tunnel experiment confirmed that the dualsolution of RR and MR exist at Ma_(∞)=6.The flow structures,including the intersection point between the detached shocks,the intersection point between the separated shock,and the size of the counter-rotating vortex pair are identified to establish a transition criterion of RR↔MR.In the dual-solution domain,the maximum wall pressure in RR is approximately 2—3 times of that in MR,indicating that the hysteresis causes a sudden change in aerodynamic loads on the cowl lips.

关 键 词：流体力学 V字形钝前缘 激波干扰 来流马赫数 迟滞现象 

分 类 号：O354.5[理学—流体力学]