Inverse Design Method for Supersonic Biplane for Lower Drag Flight

An inverse design method is applied based on Busemann biplane and Licher biplane to raise the lift-drag ratio of supersonic biplane. Numerical simulation results demonstrate that the wave drag can be reduced by 11.5% and the lift-drag ratio rises by 13.0% after optimization in inviscid fluid. It takes 15 iterations to get convergent results, which demonstrates the efficiency of the method. A new stair target pressure distribution is developed to overcome setbacks of the original one by analyses of aerodynamic forces. The lift-drag ratio of the new target Cp can be increased by 14.6%. Furthermore, Euler equations in the optimization method have been replaced by Navier-Stokes equations to investigate the influence of viscous fluid. The results indicate that the effect of the optimization with the original target pressure distribution is restrained, while the results of the new stair pressure distribution almost stay the same level and more practical value.