Flow Mechanism and Feasibility Investigation of Hypersonic Jet Control Surface

Hypersonic vehicle is a kind of vehicle that can fly at more than Mach 5 in the atmosphere. To solve the control problem of hypersonic vehicle, this work investigates the feasibility of hypersonic jet control surface. The numerical simulation method based on compressible Reynolds averaged Navier-Stokes equations with SST turbulence model is adopted. Firstly, the mechanism of hypersonic flow around airfoil with different deflection angles of aerodynamic control surface, which is arranged at the rear 30% of the airfoil behand a 2% chord gap, is analyzed and studied in detail. Then, a jet nozzle is set on the trailing edge of the airfoil to calculate and analyse the jet control effect of different total pressure ratio with 1.5mm gap (Mach 5, total pressure ratio from 1 to 300, altitude 40km). Thus, the flow mechanism, aerodynamic characteristics and control efficiency of the jet control surface is obtained. The results demonstrate that the aerodynamic control surface is effective in the hypersonic flow, and the control effect is proportional to the deflection angle of the control surface. Besides, the jet control surface also has control efficiency, which changes linearly with the total pressure ratio of the jet. And with the increase of jet total pressure ratio, the jet control surface can achieve the same control ability as the aerodynamic control surface. It reveals that the jet control surface is potentially a good control technique for hypersonic vehicle.