Plasma-based experimental investigation of compression corner shock wave/boundary layer interaction control under hypersonic quiet and noise inflow conditions

Shock wave/boundary layer interaction (SWBLI) is a pervasive phenomenon in both internal and external flows of supersonic/hypersonic vehicles. Typically, SWBLI induces significant flow separation, which adversely affects aerodynamic performance and intake efficiency. Therefore, it is essential to investigate the characteristics of supersonic/hypersonic SWBLI and develop effective flow control strategies to mitigate its effects. However, most existing studies on SWBLI and its plasma-based control have been conducted under conventional high-noise inflow conditions, while research in low-noise or quiet environments remains limited, and comparative studies between the two are even scarcer. Conducting combined investigations of SWBLI characteristics and flow control under both quiet and conventional noise conditions is thus of considerable significance. In this study, experiments were performed in a hypersonic quiet wind tunnel using a compression ramp–flat plate model under both quiet and noise inflow conditions. High-speed schlieren visualization was employed to examine the time-averaged and unsteady characteristics of a typical SWBLI, and a comparative analysis was carried out. Subsequently, plasma actuation was applied to control SWBLI in both flow states, and the control effectiveness was compared to explore the underlying mechanisms of flow control. The results show that the separation region in the quiet flow is approximately 8% larger than that in the noise flow. In the noise flow, plasma actuation perturbs the shock system, reducing its strength and mitigating low-frequency shock unsteadiness. In contrast, in the quiet flow, the shock structures undergo noticeable distortion, deformation, and even upward displacement under plasma impact, and their dynamic behavior becomes dominated by harmonics of the actuation frequency. This work provides valuable support for the design of vehicle internal/external configurations and for the optimization of flow control strategies targeting hypersonic shock wave/boundary -layer interactions.