超声速进气道出口封闭的非定常流动特性研究  

Investigation on unsteady flow characteristics of a supersonic inlet with exit blocked

作　　者：温玉芬[1] 张炜群 郝思思 WEN Yufen;ZHANG Weiqun;HAO Sisi(China Academy of Launch Vehicle Technology,China Aerospace Science and Technology Corporation,Beijing 100076,China)

机构地区：[1]中国航天科技集团公司中国运载火箭技术研究院,北京100076

出　　处：《北京航空航天大学学报》2025年第3期772-783,共12页Journal of Beijing University of Aeronautics and Astronautics

摘　　要：冲压发动机转级过程中可能会出现进气道入口通流、出口封闭的盲腔流动现象,使得进气道发生大幅气流振荡,飞行器面临姿态失稳和结构破坏的风险。针对进气道的气流振荡问题,对一种超声速双侧布局进气道在出口封闭状态下的非定常流动特性开展风洞试验和数值仿真研究,获得了模型尺寸、来流马赫数及边界层吸除对进气道压强振荡特性的影响。结果表明:出口封闭时,进气道发生周期性的流动振荡现象,气流振荡频率与来流声速成正比,与进气道长度成反比,压强振荡峰值与来流总压接近,且随着来流马赫数的增大显著上升。采用的数值仿真方法较好地模拟了进气道出口封闭状态下的非定常流动,数值仿真结果与风洞试验结果吻合良好。非定常仿真结果进一步表明:在气流振荡过程中,进气道内收缩段的边界层吸除槽可以起到泄压作用,使得进气道头部斜激波系在回退过程中达到封口状态,捕获的流量系数较无边界层吸除槽时明显增大,从而导致了进气道压强振荡峰值上升49.47%,频率下降21.78%。Cavity flow oscillation phenomenon would occur during the transiton of ramjet with the inlet entrance unobstructed while its exit blocked.As the flow oscillating dramatically,the flight vehicle would face a crisis of instability attitude controlling and structural failure.Due to the problem of fluctuation flow,the unsteady flow characteristics of a supersonic twin-duct inlet with its exit blocked were studied by wind tunnel test and numerical simulation.The effects of the model scale,Mach number of the incoming flow,and boundary layer suction on the characteristics of oscillating pressure of the inlet were acquired.The results indicate that periodic oscillating flow is observed when the exit of the inlet is blocked.The frequency of the oscillating flow is positively correlated to the acoustic velocity of the incoming flow but inversely correlated to the length of the inlet.The oscillating pressure peak is found to approximate the total pressure value of the incoming flow,and it raises obviously with the increment of the Mach number of the incoming flow.The unsteady flow of the inlet with its exit blocked is approximately simulated by the numerical method adopted in this paper,and the numerical simulation result agrees well with that of the wind tunnel test.Furthermore,unsteady simulation results show that the inlet’s pressure is relieved in the duration of flow oscillation by conducting the boundary layer suction method at the internal contracted region,which results in a shock-on-lip state during the backward movement of the shock wave system.A rise of captured flow coefficient is observed when compared to the inlet without boundary layer suction,leading to a 49.47%increase of amplitude peak while 21.78%descending of the frequency for the oscillating pressure.

关 键 词：超声速进气道 振荡压强 边界层吸除 非定常 风洞试验 

分 类 号：V221.3[航空宇航科学与技术—飞行器设计]