Experimental and numerical study on double wedge shock/shock interaction controlled by a single-pulse plasma synthetic jet

The phenomenon of shock/shock interaction (SSI) is widely observed in high-speed flow, and the double wedge SSI represents one of the typical problems encountered. The control effect of plasma synthetic jet (PSJ) on double wedge type-VI and type-V SSI was experimentally and numerically investigated, and the influence of discharge energy was also explored. The findings indicate that the interaction between PSJ and the high-speed freestream results in the formation of a plasma layer and a jet shock, which collectively governs the control of SSI. The control mechanism of single-pulse PSJ on SSI lies in its ability to attenuate shock and SSI. For type-VI SSI, under the control of PSJ, the original second-wedge oblique shock is eliminated, resulting in a new type-VI SSI formed by the jet shock and the first-wedge oblique shock. For type-V SSI, under the control of PSJ, Mach stem, supersonic jet and the reflected shocks are significantly attenuated, resulting in a transformation of type-V SSI into type-VI SSI. The numerical results indicate that the maximum reduction of peak pressure is approximately 32.26%. The development of PSJ also extends in the Z direction. The pressure decreases in the area affected by both PSJ and jet shock due to the attenuation of the SSI zone. The control effect of PSJ on SSI is gradually enhanced with increasing discharge energy.