Supersonic cavity flow control at different geometrical configuration using plasma actuator array

Cavity flow in scramjet combustor exhibits strong sensitivity to geometric configurations, posing significant challenges for flow control. Understanding the influence of key geometric parameters on control effect is crucial for the engineering application of flow control methods. In this paper, a spanwise pulsed spark discharge array is employed to control a Mach 2.0 cavity flow at different geometrical parameters, including length depth ratio (L/D), aft wall angle (θ) and offset ratio (OR). The high-speed schlieren imaging and planar laser scattering techniques are used to reveal the flow evolution under plasma actuation. Results show that the wavy shear layer that contains several plasma-induced channel structures can be observed in all testing cases. It means the plasma actuator array has the ability to enhance the momentum exchange of cavity shear layer at different geometrical parameters. Further, the effect of different geometrical parameter on the cavity flow control is revealed. For the length depth ratio, the increase in L/D is beneficial to obtain a better control outcome in cavity flow control. But for the offset ratio, the law is opposite that the increase in OR leads to a poor control outcome. And for the aft wall angle, a better control effect is achieved at θ=45° Finally, integrating the RMS statistical results and PLS images, it is inferred that the penetration depth of cavity shear layer plays a key role on the cavity flow control.