Adjoint⁃based aero/stealth optimization design for UAV

The shape design of the stealth UAV needs to give consideration to both aerodynamic and stealth perfor⁃ mance and balance these two disciplines. To further tap the potentials of UAV，this paper adopts a multidisciplinary optimization design method to refine the shape. Firstly，an adjoint method for solving the gradient of Radar Cross Sec⁃ tion（RCS）of a homogeneous medium target is established. The target with the stealth material is treated as a homo⁃ geneous medium. The RCS of the homogeneous medium is solved by the Poggio-Miller-Chang-Harrington-Wu-Tsai （PMCHWT）equation. Secondly，a multidisciplinary gradient optimization design system for aero/stealth is established by combining the Reynolds average Navier-Stokes equation solver，the free form deformation parameterization method，the inverse distance weight mesh deformation algorithm，the sequential quadratic programming algorithm，and the adjoint method. Finally，the aero/stealth optimization design of the shape of a UAV is carried out. The results show that the aerodynamic and stealth performance of the optimized shape is improved，which verifies the effective⁃ ness of the method proposed. © 2024 Chinese Society of Astronautics. All rights reserved.