Dynamic stall has always been a key problem restricting the improvement of aircraft maneuverability. In this paper, the application potential of dual synthetic jets (DSJ) technology in dynamic stall control is studied. The influence of different momentum coefficients and action positions on the control effect is analyzed, and the aerodynamic control characteristics and the accompanying flow field evolution are explained. DSJ technology can improve the dynamic stall flow field environment. When the control is continuously applied at a single position throughout the pitching process, leading edge DSJ performs best, the middle DSJ is followed, and trailing edge DSJ only increases the lift during the upstroke process. Based on the above research results, a new dynamic stall control concept—the trade-off control concept is introduced, and three new control strategies, optimal control, trade-off control, and separation control, are proposed. The three control strategies have achieved better effect of increasing lift. For the whole pitching process, the average lift coefficient is increased by 19.72%, 20.98%, and 22.63%, respectively. For the downstroke process, the average lift coefficients of the three control strategies are increased by 45.30%, 48.91% and 54.56%, respectively. Among these strategies, the trade-off control concept achieves the best lift increase in the upstroke process, and the separation control concept is more effective for the control of the whole pitching process.

The control of a shock wave produced by a ramp (ramp shock) in Ma3 supersonic flow using a two-electrode SparkJet (SPJ) actuator in a single-pulse mode is studied experimentally. Except for schlieren images of the interaction process of SPJ with the flow field, a dynamic pressure measurement method is also used in the analysis of shock wave control. In a typical experimental case, under the control of single-pulsed SPJ, the characteristic of ramp shock changes from “short-term local upstream motion” in the initial stage to “long-term whole downstream motion” in the later stage. The angle and position of the ramp shock changes significantly in the whole control process. In addition, the dynamic pressure measurement result shows that the ramp pressure is reduced by a maximum of 79% compared to that in the base flow field, which indicates that the ramp shock is significantly weakened by SPJ. The effects of some parameters on the control effect of SPJ on the ramp shock are investigated and analyzed in detail. The increase in discharge capacitance helps to improve the control effect of SPJ on the ramp shock. However, the control effect of the SPJ actuator with medium exit diameter is better than that with a too small or too large one. In addition, when the SPJ exit is located in the separation zone and outside, the change in the ramp shock shows significant differences, but the control effect in the case of medium ramp distance is better when the SPJ exit is located outside the separation zone.

Plasma synthetic jet (PSJ) is widely employed in flow control due to its advantages of zero-mass and fast-response. A novel measurement method for high-frequency dynamic drag variation was adopted in a Mach 8 wind tunnel experiment, demonstrating that the opposing PSJ can achieve a maximum drag reduction of 40.27% and an average drag reduction of 13.25% within one discharge cycle. Subsequently, the numerical method was verified in detail and the effects of different discharge energies and nozzle diameters on the drag reduction characteristics of the opposing PSJ were studied. The results show that an increase in discharge energy is beneficial for the drag reduction characteristics of the opposing PSJ, although the efficiency remains relatively low. In contrast, increasing the nozzle diameter enhances the average drag reduction but significantly reduces the duration of effective control. The drag reduction mechanism of the opposing PSJ can be attributed to the combined effects of pushing the strong bow shock away to form a weaker oblique shock, followed by the reattachment of the shock downstream.