Abstract:
Based on the aerodynamic control principle that direct current discharge reconstructs the shock waves, wind tunnel experiments at Mach 6 were conducted for the hypersonic aerodynamic control of a conical model with ramps. The aerodynamic force/moment variations of the model at two discharge powers (284 W and 517 W) were acquired using the fiber optic balance (FOB), and the corresponding flow topology change was studied using the Schlieren imaging. The visualisation reveals the shock wave reconstruction phenomenon caused by the discharge, which blocks the flow and reduces the local Mach number. Specifically, the discharge induces a compression wave, and reduces the strength and angle of the attachment shock. The balance signal shows that the axial force, normal force and pitching moment of the model are all decreased under the discharge, and the control effect is more prominent under a larger discharge power. The heating effect of discharge was simulated by solving the Navier-Stokes equations with an energy source, and the aerodynamic force variation with the power density, as well as the control effect of the heating position were quantified. The results show that, the aerodynamic changes are positively correlated with the power density; the pitch moment of the model changes significantly taking the position upstream of the actuator as the reference point; the control efficiency decreases when the heating zone is located closer to the ramp.