关键词: 乘波体, 双后掠, 大迎角, 非线性增升, 激波附着

Abstract: The double swept waverider is a typical application of the planform-customized osculating-cone waverider. The satisfactory wide-velocity-range performance and the nonlinear increase of the lift for the double swept waverider at high angle of attack are well worth studying. The aerodynamic performance of the double swept waverider is calculated and compared with that of the single swept waveriders. Results suggest that the nonlinearity of the lift of the double swept waverider is stronger than that of the single swept waverider, and the nonlinearity effect increases as the Mach number increases. Since the main lift of the waverider comes from the lower surface rather than the upper surface, and the flow field above the upper surface in the hypersonic state is different from that in the subsonic state, the explanation to "vortex lift" remains questionable. This article proposes an alternative explanation that the nonlinear lift increase is related to the attachment of shock wave influenced by the sweep angle. The smaller the sweep angle is, the stronger the shock wave attaches to the waverider. In reference to the function of the oblique shock wave, the attachment ensures that the pressure increase via angle of attack is nonlinear, leading to the nonlinearity of the lift. When the shock wave detaches from the waverider, the increase of the lift brcomes approximately linear.

Key words: waverider, double swept, high angle of attack, nonlinear lift increase, shock wave attachment