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压缩拐角激波与边界层干扰问题广泛存在于高速飞行器的外部和内部流动中,其非定常复杂流场结构对飞行器气动性能影响显著.动力学模态分析将有助于进一步加深理解激波与边界层干扰流场不同特征频率对应的流动结构及动力学特性,为揭示其复杂流动机理提供参考.本文采用动态模态分解(DMD)方法对来流马赫数为2.9、24°压缩拐角内激波与超声速边界层干扰下的非定常流动进行了模态分析.评估了稀疏改进动态模态分解方法在压缩拐角流动中的适用性,研究了湍流干扰和转捩干扰下典型特征频率对应的动力学模态空间结构差异及其原因,分析了转捩边界层展向非均匀性对低频/高频模态动力学机制的影响规律.研究发现,湍流干扰与转捩干扰下拐角干扰区内均存在两类截然不同的动力学模态:低频模态和高频模态.低频模态结构集中在分离激波及分离泡剪切层的根部,表征为分离泡的大尺度膨胀和收缩运动;高频模态空间分布则以平均声速线附近正负交替结构为主,对应为边界层内不稳定波沿剪切层往下游的传播.转捩边界层的展向结构对低频模态运动特性影响明显,而对高频模态的影响则相对较小.“,”Shock wave and boundary layer interactions exist widely in the internal and external flow of high speed vehicles.The complicated unsteady flow field has significant effect on the aerodynamic performance of aircraft.Dynamic modal analyses of unsteady motions are helpful to deeply understand the flow structures and dynamical properties of characteristic frequencies in the interactions,providing information to reveal the complex mechanism of the flow.A modal analysis of the unsteady flow field in shock wave and boundary layer interaction for a 24° compression ramp at a Mach number 2.9 is performed by using Dynamic Mode Decomposition (DMD).The applicability of sparsity-promoting DMD in the compression ramp is systematically evaluated.The differences of and reasons for the spatial structures of the dynamic mode corresponding to characteristic frequencies between turbulent and transitional interactions are studied.The influence of spanwise non-uniformity of the transitional boundary layer on the dynamics mechanism of the high and low frequency modes is analyzed and compared.It is found that low frequency modes are characterized by the separation shock and the foot of separated shear layer,exhibiting the breathing motion of the separation bubble.The spatial structures of high frequency modes are dominated by the alternating structures around the mean sonic line,corresponding to the propagation of instable waves past the shear layer above the separation bubble.Additionally,the spanwise non-uniformity has significant effect on the dynamic properties of low frequency modes,while a little effect on those of high frequency modes.