Efficient Multidisciplinary Aerodynamic Optimization Design Based on Discrete Adjoint Method

Abstract

An approach for the aerodynamic optimization design of elastic configuration is implemented and tested. Aeroelastic analysis was carried out by coupling Euler equations solver and finite-element structural solver. Two important techniques used in high-fidelity aerostructural design optimization are discussed, which are the grid deformation method and the update method of finite-element mesh (FEM). An improved grid deformation methodology based on transfinite interpolation (TFI) and radial basis function (RBF) method is presented, which adapts to complex configuration very well. The technique to update the FEM is based on bilinear interpolation method and RBF method, and it adapts to any grid type of finite-element model. Discrete adjoint method is used to get the gradient of 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 the optimization design of transonic jig shape of aircraft.