分离流状态下单边膨胀喷管内激波反射特性  

Shock reflection characteristics in single expansion ramp nozzle under flow separation condition

作　　者：李耀华 李建强 何成军 苗磊 梁锦敏 高荣钊 LI Yaohua;LI Jianqiang;HE Chengjun;MIAO Lei;LIANG Jinmin;GAO Rongzhao(High Speed Aerodynamics Institute,China Aerodynamics Research and Development Center,Mianyang Sichuan 621000,China;Aerospace Technology Institute,China Aerodynamics Research and Development Center,Mianyang Sichuan 621000,China)

机构地区：[1]中国空气动力研究与发展中心高速空气动力研究所,四川绵阳621000 [2]中国空气动力研究与发展中心空天技术研究所,四川绵阳621000

出　　处：《航空动力学报》2023年第9期2279-2287,共9页Journal of Aerospace Power

摘　　要：在单边膨胀喷管(SERN)内流动分离状态下,综合采用试验和数值模拟手段对喷管内激波反射特性进行研究,分析了单边膨胀喷管内激波反射结构,对比了不同激波反射模式下的流动分离特性。结果表明:喷管落压比(NPR)由3.06向5.07变化的过程中,喷管内激波反射由马赫反射(MR)向规则反射(RR)转换,喷管上、下壁面非对称导致MR具有明显非对称特征;通过激波极曲线理论分析非对称MR形成机制,马赫杆上游垂直流向方向的压力梯度是非对称MR形成的根源;振荡NPR条件下,在一个完整周期内,激波反射未出现明显迟滞现象,但激波运动位置变化存在明显的迟滞效应,NPR上升下降过程中激波位置的差量随振荡频率增大而增大,较低(或较高)频振荡NPR条件下激波位置振荡幅值较大(或较小)。Combined with the focus schlieren and dynamic pressure measurement technology,the shock reflection inside a single expansion ramp nozzle(SERN)was investigated under the condition of flow separation.The flow characteristics of shock reflection were analyzed,and the flow separation characteristics were compared for different wave configurations of shock reflection.Results showed that the shock reflection configuration transitioned from Mach reflection(MR)to regular reflection(RR),during the change of nozzle pressure ratio(NPR)from 3.06 to 5.07.The MR structure inside SERN was obviously asymmetrical duo to the asymmetric upper and lower walls.Based on shock polar representation,the mechanism of asymmetric MR was analyzed.The pressure gradient in the vertical flow direction upstream the Mach stem was the source of asymmetric MR.A hysteresis did not exist in the transition process between RR and MR,during increasing and decreasing processes of NPR,but the shock position experienced a hysteresis effect.The percentage deviation of shock position increased with the increasing oscillation frequency,during increasing and decreasing processes of NPR.The lower oscillation frequency of NPR indicated the larger oscillation amplitude of shock position.

关 键 词：单边膨胀喷管(SERN) 激波反射 马赫反射(MR) 规则反射(RR) 喷管落压比(NPR) 激波位置 迟滞现象 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程]