Abstract:
Aerospace vehicles have a wide velocity range that spans subsonic to hypersonic speeds. In such a wide speed range, their aerodynamic characteristics vary so significantly that traditional airfoils are improbable to satisfy the aerodynamic requirements for low- and high-speed flights at the same time. This paper proposes the requirements of airfoils and wings for aerospace vehicles, with especial attention being paid on the high lift at low speeds, high lift-to-drag ratio at high speeds, lift and gravity matching design, as well as structure and thermal protection design. In addition, an integrated design of airfoil and wing plane shape is carried out by numerical simulations based on a wide-speed-range airfoil. A new wing with spanwise-varying airfoils is obtained. Compared with the original wing, the lift efficiency of this new wing at low speed is increased by 36.3%. The lift-to-drag ratios at the lift-weight-balance point is increased by 33.4% and 12.9% respectively for supersonic and hypersonic flights. Since the new wing has good aerodynamic characteristics in the whole velocity range, it is further applied to a typical aerospace vehicle by an integrated optimization. The lift-to-drag ratio at the lift-weight-balance point is further improved by 5% at high subsonic speed, 10.3% at supersonic speed, and 0.7% at hypersonic speed. The contradiction between high lift at low speed and high lift-to-drag ratio at high speed is alleviated. An aerospace vehicle layout that meets the overall design requirements for wide-speed-range flight is obtained. The results have certain engineering guiding significance.