Our experimental study explored the impact of pulse discharge energy deposition, across a wider frequencies ranging from 5 kHz to 20 kHz, on a Shock Wave/Boundary Layer Interaction (SWBLI) at a Mach number of 2.47. Using high-speed schlieren imaging, Planar Laser Scattering (PLS) and Focused Laser Differential Interferometry (FLDI), we analyzed the characteristics of discharge-induced energetic eddies and their impact on SWBLI. The Spectral Proper Orthogonal Decomposition (SPOD) was employed to scrutinize the structural transformations of the flow field under the influence of pulse discharge. Our findings indicate that pulsed discharge significantly alters the flow field by propelling the separation shock upstream, with this effect intensifying as the discharge frequency increases. Additionally, the discharge diminishes the fluctuation intensity of the separation shock and the shear layer, and it reduces the low-frequency spectral energy of the separation shock. SPOD analysis revealed that at high discharge frequencies, the flow field dynamics shift from the low-frequency oscillations of the separation shock to the motion of vortices along the boundary layer, which interact with the shock waves. The control efficacy of pulsed discharge on SWBLI demonstrates remarkable consistency and intensity at frequencies of 10 kHz or higher, whereas a notable attenuation in effectiveness is observed at 5 kHz. This reveals a critical frequency threshold beyond which flow characteristics change markedly, primarily seen in the progressive weakening of the separation shock. However, further frequency increases beyond this point yield diminishing returns in SWBLI control effectiveness.

Improving the mixing efficiency of wall-normal jets in supersonic flows is crucial for enhancing combustion efficiency and conserving fuel. Pulse discharge energy deposition has been shown to be an effective method for enhancing mixing of transverse jets. The study investigates the structure of transverse jets and the effectiveness of control methods influenced by the momentum flux ratio. Experiments were carried out in a wind tunnel with an incoming flow Mach number of 2.47, focusing on how upstream plasma energy deposition arrays could improve the mixing of downstream transverse jets. Employing high-speed schlieren and planar laser scattering techniques, the research unveiled the impact of high-frequency energy deposition on the flow field structural characteristics of single-hole jet injection and the effects of single-pulse energy deposition on double-hole jet injection. Furthermore, the fluctuation and spectral characteristics of the flow field were elucidated using time-resolved schlieren image-based root mean square and fast Fourier transform methods. The evolution mechanism of transverse jets under high-frequency discharge was probed using the Spectral Proper Orthogonal Decomposition (SPOD) technology. The findings indicate that pulse discharge energy deposition can generate “energetic eddies,” which substantially altered the jet structure. These eddies diminished the bow shock wave, decreased the low-frequency oscillations of the shock wave, and created super-largescale wake vortices that are in sync with the discharge frequency within the jet plume. This resulted in a significant improvement in the penetration depth and spanwise width of the jet near the wall. When the energetic vortex interacted with the downstream bow shock, secondary reinforcement occurs. It is also demonstrated that high-frequency energy deposition markedly boosted the fluctuation intensity of the jet. As the momentum flux ratio increased, the disturbance capability of energy deposition was enhanced, and the range of disturbance also expanded.