Effect of the novel discharge strategy for plasma synthetic jet on the drag and heat reduction in hypersonic flow

Reducing shock wave drag and heat flux is crucial for improving the performance of hypersonic vehicles. As an efficient flow control technology, the plasma synthetic jet actuator (PSJA) has attracted considerable attention in the field of shock control. A novel discharge strategy is proposed in this study to enhance the control effect on the flow field by performing multiple discharges during the blowing phase of the PSJA. The effect of the novel discharge strategy on the control of the flow field is investigated, and the effects of the discharge interval, the discharge energy ratio, the total discharge energy, and the number of discharge on the drag and heat reduction are analyzed in detail. The results show that a shock-breaking effect is formed due to the effect of plasma synthetic jet generated after the first discharge on the shock. The plasma synthetic jet generated by the subsequent discharge can act on the bow shock with lower dissipation, resulting in a higher velocity of the jet. The duration of shock detachment is prolonged and the control effect of the flow field is enhanced. The subsequent discharge is triggered when the discharge region density reaches its peak, and the control effect of the flow field is the best. The higher discharge energy ratio enhances drag reduction, which can be improved by 2.44%. The lower discharge energy ratio is more beneficial to heat reduction, which can be increased by 9.55%. For different total discharge energy, the drag and heat reduction achieved are optimal when using a two-discharge strategy.