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Airfoil design characteristics7/1/2023 In hypersonic flight, wave drag accounts for the majority of drag and the associated heat flow is usually highest at the head of the aircraft. In the aspect of drag reduction and heat prevention, the research mainly focuses on the head shock wave. ![]() ![]() Active flow control techniques such as blowing-off, 15 pumping, 16 and wall blowing 17 are introduced to suppress or eliminate boundary layer separation and ensure flow field stability. 14 In boundary layer control, the research focuses on shock/boundary layer interference control and boundary layer transition control. 12,13 A control effect equivalent to a conventional aileron deflection of 3° was achieved when α = 1.342°, M = 0.716, and the jet flow coefficient was 0.003.įor supersonic and hypersonic conditions, active flow control technology is mainly applied to boundary layer control and forward shock drag reduction and heat protection. Forster and Steijl 11 of Liverpool University conducted numerical simulations and optimizations of circulation control technology at transonic speeds. In the subsonic range (M = 0.85–0.88), circulation control technology increased the maximum lift coefficient of the model, effectively suppressed separated flow on the flap, and delayed the position of the shock wave. The NASA Langley Research Center in the United States expanded the application of this circulation control technology from low speeds to subsonic speeds in their Fundamental Aerodynamics Subsonic/Transonic-Modular Active Control 9,10 research. This verified the feasibility of this circulation control technology at low speeds. 8 A pair of circulation control devices located on the outer portions of the wings achieved roll attitude control, and another pair installed inboard on the wings achieved pitch attitude control. In 2010, the flapless air vehicle integrated industrial research project conducted a successful trial flight of the Demon unmanned technology demonstrator. This increases the wing circulation to increase lift, reduce drag, and reduce energy consumption. Using an improved design for the Coanda surface at the trailing edge of the wing, high-pressure gas is ejected to create a tangential jet along the trailing edge of the surface. Low-speed theoretical research and flight test verification of circulation control technology is relatively mature. It can optimize the aerodynamic characteristics, increase or reduce lift, produce pitching moment simultaneously, enhance the efficiency of the rudder surface, and assist attitude control. The results prove that, under the condition of high altitude and low pressure, if jet excitation is applied on the surface of the hypersonic airfoil, a local high pressure area will be formed in front of the excitation port, and the differential pressure between upper and lower wings will be changed. After that, typical excitation states of numerical simulation are selected for hypersonic wind tunnel experiment verification, whose results are in good agreement with those of the numerical simulation. First, the influence of different jet excitation parameters on the scheme is explored through numerical simulation, mainly including the Mach number, the jet location, the jet angle, and the change with the angle of attack. In this paper, a two-dimensional hypersonic airfoil is selected to analyze the feasibility and control effect of jet flow control technology under hypersonic inflow, and a flow control scheme is designed to make the jet eject from the wing surface. In the field of low speed, subsonic speed, and supersonic speed, many experiments and numerical simulations have been carried out to verify the excellent auxiliary or control effects of active flow control technology on aircraft. ![]() Active flow control technology can improve the aerodynamic performance of the aircraft while optimizing its control attitude. Raising the aircraft lift-to-drag ratio, improving the efficiency of attitude control, and optimizing aerodynamic performance are important goals. Hypersonic aircraft represent an important area of aerospace development.
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