Abstract
The separated boundary layer on an airfoil is highly receptive and unstable to external disturbances and forcings. In the present study, the response of the airfoil boundary layer with separation bubble to acoustic forcing is examined experimentally for NACA0015 airfoil at an angle of attack 10°, at a chord Reynolds number 4.4×104. The results show that when the acoustic forcing is applied, discrete vortices are excited immediately downstream of the separation point and they can govern the flow development upto the station near the trailing edge, through controlling the streamwise and spanwise scales of turbulent vortical structures within the airfoil boundary layer.
