Aerodynamic optimization design of aircraft at maneuver points based on discrete adjoint equations

Modern supersonic aircraft with low aspect ratio must achieve favorable subsonic and supersonic cruise efficiency and high maneuverability. However, conventional aerodynamic optimization has primarily focused on cruise lift-to-drag characteristics, with limited attention paid to maneuverability at high angles of attack, yielding designs that fail to satisfy practical engineering requirements. To address this gap, a discrete adjoint aerodynamic optimization design method based on an upwind scheme is developed. A high-fidelity adjoint-gradient optimization framework is established based on the free form deformation (FFD) method and the sequential quadratic programming (SQP) algorithm. This framework is applied to the maneuverability optimization of a low-aspect-ratio wing at high angles of attack under supersonic conditions, and the resulting configurations are evaluated for both cruise aerodynamic performance and overload characteristics across subsonic and supersonic flight regimes. The results indicate that the optimized configuration achieves an increase in normal overload of approximately 0.1 g at Ma = 0.9 and 0.27 g at Ma = 1.5. The maneuverability of the aircraft is improved under transonic and supersonic conditions, while the cruise lift-to-drag characteristics are essentially preserved. These findings demonstrate the applicability of the proposed method to complex engineering problems and provide valuable guidance for practical design applications.