Closed-Loop Control of Dynamic Oblique Shock with Arc Plasma

Abstract

The fluctuations caused by the dynamic shock wave and its interaction with the boundary layer bring formidable challenges for aerodynamic design and stable control of supersonic aircraft. The mechanism of closed-loop control for dynamic oblique shock stabilizing with arc plasma is numerically studied. Two types of dynamic oblique shocks are formed in supersonic airflow by a compression ramp rotation and incoming Mach number variation, respectively. A closed-loop controller is established to connect the arc plasma deposited power with the pressure ratio across the dynamic shock by using the proportional-integral method. It realizes the shock pressure ratio stabilized in the desired target value with a local overshoot appearing at the initial excitation and a more stable flow downstream of the oblique shock during excitation state for both types of dynamic shock control. The effects of arc plasma length and ramp rotating speed on the closed-loop control for the dynamic shocks induced by ramp rotation are further discussed. Results show that the arc plasma with longer length is more favorable to the dynamic oblique shock control with lower energy consumption and total pressure loss. The pressure ratio fluctuation is increased at higher ramp rotation speed, but its standard deviation is still limited to 0.3% of the desired target value during excitation state.