The evolution of asymmetric shock reflection with a vibrating wedge

Lightweight structural design improves vehicle performance but reduces stiffness, making prescribed wall motion relevant to shock-reflection behavior. This study employs computational fluid dynamics simulations with a prescribed harmonic motion of the wedge to investigate how the vibration amplitude and frequency influence asymmetric shock reflections. The flow fields of both Mach reflection (MR) and regular reflection (RR) are shown to exhibit four evolution forms under the vibrating boundary. The corresponding distribution domains and evolution trajectories with respect to vibration frequency are summarized. Further analysis shows that increasing the vibration to upper or lower limits delays MR → RR transitions and advances RR → MR transitions within a vibration cycle, whereas increasing frequency postpones both transitions. Based on this, we examine the variation of MR–RR transition boundaries with amplitude and frequency. From the perspective of flow physics, the instantaneous MR–RR transition in the present unsteady cases is shown to be consistent with the sonic criterion. It is also found that the flow field exhibits a notable lag relative to the prescribed wedge motion, which is identified as a key mechanism contributing to the MR–RR transition-boundary variation and hysteresis behavior in the present prescribed-wedge-motion cases. These findings clarify the mechanisms of vibration-induced asymmetric shock-reflection evolution and provide physical insight into high-speed configurations involving moving or vibrating walls.