Aerodynamic Shape Optimization Based on Drag Decomposition

An advanced drag prediction method, mid-field drag decomposition method is applied in aerodynamic shape optimization problems. The drag decomposition method decomposes total drag into wave, profile, induced and spurious drag component, the latter resulting from the effect of numerical diffusion included in CFD results. Hence the more accurate drag prediction can be achieved by the elimination of the spurious drag component. This method is applied in transonic airfoil, planform and winglet shape optimizations. As the optimizer and flow solver, genetic algorithm and Euler/NS simulation are used, respectively. The results show that the optimizations based on the drag decomposition method are reliable and accurate. Moreover, precise investigation of the drag reduction mechanisms is achieved by using the drag decomposition method.