Aerodynamics and acoustics of transonic airfoil-airfoil interaction

摘要

As a 2D approximation to the outer region of a coaxial rotor, the flow fields induced by transonic airfoil-airfoil interaction are numerically simulated to investigate the aerodynamic and acoustic characteristics. ^A new approach is suggested to minimize the numerical compression wave generated when imposing the initial conditions for an asymmetric unsteady flow field, and it is shown to be very efficient for saving computation time. ^The processes of aerodynamic load fluctuation are monitored with time for a transonic flow field. ^It is found that abrupt pressure disturbances around the leading edge of the upper airfoil induced by the shock wave of the lower airfoil and the ensuing oscillation of the shock wave cause the severe aerodynamic load fluctuation in the upper airfoil, and a strong sound wave is radiated from the upper airfoil in some cases. ^(Author)