冲压发动机进气道扩压段局部结构弹性较大时,壁板振动与跨声速非定常流动相互耦合,影响进气道整体性能。基于流固耦合方法,研究了扩压器内跨声速流动与局部弹性壁板的耦合作用,分析了结构阻尼对扩压器流固耦合振动特性的影响规律。结果表明,通过调整弹性壁板阻尼可以削弱和抑制正激波自激振荡引起的扩压器壁板流固耦合振动。无阻尼弹性壁板中点无量纲振动幅值为0.37。给定刚度等效阻尼系数1×10-5时振幅下降至0.22;增加阻尼系数至4×10-5时,扩压器壁板流固耦合振动消失,进入静平衡状态。 When the local structure of ramjet inlet diffuser section is more elastic, the vibration of the siding and the transonic unsteady flow are mutually coupled, which affects the overall performance of the inlet duct. Based on the fluid-solid coupling method, the coupling effect between transonic flow and local elastic wall in diffuser is studied, and the influence of structural damping on the fluid-solid coupling vibration characteristics of diffuser is analyzed. The results show that by adjusting the damping of the elastic wall, the fluid-solid coupling vibration of the diffuser wall can be weakened and suppressed. The dimensionless vibration amplitude of the mid-point of the undamped elastic panel is 0.37. When the equivalent damping coefficient of 1 × 10-5 stiffness is given, the amplitude decreases to 0.22. When the damping coefficient increases to 4 × 10-5, the fluid-solid coupling vibration of the diffuser wall disappears and enters the static equilibrium state.