Compression ramp shock wave/boundary layer interaction control with high-frequency streamwise pulsed spark discharge array

Abstract

A streamwise array of pulsed spark discharge operating at a high frequency of 10 kHz is used to control the shock wave/boundary layer interaction (SWBLI) induced by a 24° compression ramp (CR) in a Mach 2.0 flow. High-speed schlieren imaging at 50 000 frames/s is deployed for flow visualization. The schlieren snapshots, as well as statistics of the schlieren sequence, show that the intensity weakening effect on the shock wave can be achieved for a long time up to 20 ms, which is the first experimental demonstration of stable control on the CR-SWBLI with plasma actuators. Then, based on fast Fourier transform analyses, the low-frequency unsteadiness of the shock wave is also significantly modified and the dominant oscillation frequency is switched to the high frequency St = 0.32. The mechanism of the encouraging control outcome is finally discussed that the strong separation wave induced by a CR is replaced by a multistage weak compression wave produced through a high-frequency actuator array.

Experimental investigation of supersonic boundary-layer tripping with a spanwise pulsed spark discharge array

“…Moreover, as the frequency increases from 6 to 14 kHz, the amplification rate grows. However, considering the performance of our power supply will severely degrade at above 10 kHz due to an insufficient recharging time of the internal capacitors (Tang et al 2020a), the actuation frequency is fixed as 8 kHz in this paper.…”

Experimental study on shock‐shock interaction over double wedge controlled by surface arc plasma array

“…Recently, Xie et al [ 11 ] used SparkJet actuator for the first time to achieve an effective control on Endey VI SSI over a double wedge in Mach 6.9 high‐enthalpy hypersonic flow, but the repeat frequency is only 1 Hz. Among the current active flow control methods, surface arc plasma actuation has shown excellent control effects in supersonic shock regulation, [ 12 ] shock/boundary layer interaction, [ 13,14 ] and supersonic boundary layer transition. [ 15 ] Besides, Wang et al [ 16 ] experimentally verified the control ability of the surface arc plasma actuation on Mach 6 hypersonic oblique shock over a ramp.…”