超声速进气道激波振荡与结构耦合动态特性研究

During the process of slow pressurization in the supersonic inlet, some complicated flow like boundary layer separation and shock wave turbulent boundary layer interactions are existed. Under certain condition, shock wave oscillation and fluctuating pressure load are generated, which the vibration response of the inlet panel structures will be excited. The response will change the flow field distribution of the boundary layer, which the state of shock wave oscillation is changed. Subsequently, the panel response is impacted deeply and the couple situation of shock wave oscillation and structure response in the inlet is generated. The inlet is in rigorous vibration and acoustic noise environment with the continuance of the couple state, which threaten the strength and device badly. Non-coupled method was used in traditional dynamic characteristic analysis of the supersonic inlet commonly. However, the feedback effect of structure to shock wave oscillation was ignored, which reduced the accuracy of fluctuating pressure load and response prediction. In this project, based on the characteristics of inner flow field of supersonic inlet, integrating fluid and structure dynamics, considering the couple of shock wave oscillation and structure response, research the fluctuating pressure and structure response of the supersonic inlet and analyze the influence law of the system parameters to the system dynamic characteristics, which lay a foundation to the design of supersonic inlet.

在超声速进气道减速增压的过程中，存在边界层分离与激波-边界层相互干扰等复杂的流动状态。这些复杂的流动在一定条件下会产生激波振荡，并由此会引发脉动压力载荷。进气道壁板结构在脉动压力载荷的作用下会产生振动响应，而该响应又会改变边界层流场分布，进而改变激波振荡的状态并进一步影响壁面响应，形成进气道激波振荡与结构响应的耦合。耦合状态的持续会使得进气道处于严酷的振动与噪声的环境中，对其结构强度及仪器设备带来严重的威胁。传统的超声速进气道动态特性分析多采用非耦合方法，忽略了结构对激波振荡的反馈作用，由此会降低进气道脉动压力载荷与结构响应预测的准确性。本项目基于超声速进气道内流场的特点，结合流体动力学与结构动力学，考虑激波振荡与结构之间的耦合，研究超声速进气道脉动压力载荷与结构响应，分析流动参数对系统耦合动态特性的影响规律，为超声速进气道的设计奠定基础。

在超声速进气道减速增压的过程中，由于边界层分离与激波-边界层相互干扰等复杂流动会引发脉动压力载荷。进气道壁板结构在此作用下会产生振动响应，该响应会改变激波振荡的状态并进一步影响壁面响应，形成激波振荡与结构响应的耦合，使进气道处于严酷的振动与噪声的环境中。本项目分析了超声速进气道脉动压力载荷与结构响应，研究了进气道壁板流固耦合动态特性，探索了流动参数对系统耦合动态特性的影响规律。结果表明，进气道内部流场存在激波串结构，使得当地脉动压力载荷较大。而出口压力对进气道脉动压力载荷特性及起动特性具有明显的影响。采用耦合方法获得的结构响应大于传统非耦合方法获得的分析结果。本项目的研究成果已应用于进气道内流场脉动压力与结构响应分析，对于含有超/高超声速进气道、蒙皮等薄壁结构的飞行器外激励源与结构响应分析具有一定的理论与应用价值。