Efficient aeroelastic design optimization based on the discrete adjoint method

An approach for the aerodynamic optimization design of elastic configurations is implemented and tested. Aeroelastic analysis was carried out by combining an Euler equations solver and finite-element structural solver. Two important techniques used in high-fidelity aerostructural design optimization are discussed: the grid deformation method and finite-element mesh (FEM) update. An improved grid deformation methodology based on transfinite interpolation (TFI) and the radial basis function (RBF) method is presented. It adapts to complex configurations very well. The technique to update the FEM is based on a bilinear interpolation method and RBF method, and it adapts to any grid of finite-element model. The discrete adjoint method is used to get the gradient of the objective function with respect to design variables. Optimizations of a wing and a more realistic wing-body configuration are done to demonstrate the effectiveness of the proposed approach. Results show that the lift-to-drag ratio can be improved with constraints through optimization, which indicates that the present methodology can be successfully applied to design optimization of jig shapes of aircraft.