ACOUSTIC EFFECTS OF PARALLEL VORTEX-AIRFOIL INTERACTION

The vortex-airfoil interaction phenomenon has been investigated experi mentally 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 i ncidence 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 n ose induces flow oscillations which are accompanied by almost harmonic acoustic wave generation.