Preliminary design of airflow-coordinated compliant morphing airfoils (Aerostructural topology optimization based on static aeroelastic deformations)

Compliant morphing airfoils (CMAs) can improve aerodynamic efficiency and structural integrity through aeroelastic deformation in response to airflow. However, designing them is challenging owing to the coupling between aerodynamic forces and structural responses. This study presents an aerostructural topology optimization method for CMAs that explicitly accounts for static aeroelastic deformation to improve integrated aerostructural performance. A two-way coupled aerostructural analysis, combining the aerodynamic panel method with the structural finite element method, was developed to evaluate aeroelastic behavior. Design sensitivities were obtained using the discrete adjoint method, and topology optimization was applied to determine the internal compliant mechanisms. Numerical examples demonstrate that the optimized CMA achieves simultaneous increases in lift coefficient and actuator input energy through static aeroelastic deformation. The effects of static aeroelastic deformation were then analyzed in detail. These results suggest that allowing static aeroelastic deformation yields a more energy-efficient design than using excessively stiff structures, which demands higher actuator input with limited lift improvement.