Abstract: Aiming at the performance requirements of solar UAV with high aspect ratio, the optimization design of the carbon fiber composite solar UAV wing was carried out in this paper. When NACA4412 was selected as the reference airfoil, the airfoil was optimized based on NSGA-Ⅱ optimization algorithm with xfoil software as the aerodynamic calculation software. On this basis, the three-dimensional modeling of the wing was carried out, the aerodynamic characteristics are analyzed using CFD software, and the fluid-structure coupling analysis of the wing was carried out using the ANSYS Workbench statics module. The results show that the lift coefficient increases by 4.20%, the drag coefficient decreases by 8.74% and the lift-drag ratio increases by 14.18% after the airfoil is optimized. Under the aerodynamic load, the pressure increases gradually from the wing root to the wing tip, and the maximum pressure at the wing tip is 242 Pa relative to the external atmospheric pressure. Under the action of external load, the maximum stress is displayed near the wing root, which is 61.397 MPa, and the maximum value of wing deformation is 40.262 mm, which meets the rigidity requirement that the allowable deformation of solar UAV is within 5%, that is the wing tip deformation shall not be greater than 5% of the half-span length. The research results can provide a theoretical reference for the design and development of carbon fiber composite solar UAV.

Key words: carbon fiber composite, solar UAV, wing structure, fluid-structure coupling analysis, optimal design