Aerodynamic Design Optimization Using the Drag-Decomposition Method

Abstract

An advanced drag-prediction method, the midfield drag-decomposition method, is applied in aerodynamic design optimization problems. The drag-decomposition method decomposes total drag into wave, profile, and induced and spurious drag components, the latter resulting from the effect of numerical diffusion included in computational fluid dynamics results. Hence, the more accurate drag prediction can be achieved by the elimination of the spurious drag component. In this paper, this method is applied in airfoil, planform, and winglet design optimizations. A conventional genetic algorithm is used as the optimizer. The results showed that the optimizations based on the drag-decomposition method were reliable and efficient. Moreover, detailed information of the drag-reduction mechanisms could be extracted by the drag-component-based investigations.