CFD analysis on sweep angles of the leading and trailing edges of a wing in a supersonic flow

To systematically investigate the aerodynamic characteristics of wings with 30, 45 and 60 degree swept-back angles, and different taper ratios, Navier-Stokes (N-S) simulations for flows over a wing have been conducted. The Mach numbers of the flows range from 0.8 to 2.8. The planforms of wings are in various shapes whose half span aspect ratios are identically fixed in 2.0. The simulation and investigation has revealed new knowledge on the relation between swept-back angles and aerodynamic characteristics of a wing in a supersonic flow. As the aerodynamic characteristics, drag coefficient CD variation is primarily observed along flow Mach number increase. Results of N-S simulations show a realistic profile of the variation which is substantially different from that by the thin-wing theory commonly printed in a textbook. Moreover, the simulation results indicate not only the swept-back angle of a leading edge but also that of a trailing edge take important role on aerodynamics of a wing. Finely, the effect of drag coefficients induced by lift is analyzed using simulation results. It is found that the induced drag in realistic supersonic flows can be treated by the thin-wing theory if three-dimensionality is properly evaluated.