ACOUSTIC EFFECTS OF PARALLEL VORTEX-AIRFOIL INTERACTION

The vortex-airfoil interaction phenomenon has been investigated experimentally in a shock tube, for the case in which the vortex and airfoil axes are parallel. The acoustic wave generated during the interaction was visualized by means of the Schlieren method. Moderate angles of incidence of the NACA 0012 airfoil at a flow Mach number M = 0.54 were considered. It was concluded that the vortex break-up at the airfoil nose induces flow oscillations which are accompanied by almost harmonic acoustic wave generation.