VORTEX SHEDDING FROM FLAT PLATES UNDER THE INFLUENCE OF AN ACOUSTIC FIELD

Experimental data obtained with two flat plates in tandem in a wind tu nnel are presented. Attention is concentrated on the phase of the vort ex shedding from the upstream plate relative to the acoustic field whe n a resonance is excited. At some plate spacings a resonance was excit ed over two ranges of flow velocity, at the lower velocities the relat ionship between phase and velocity was found to be similar to that wit h a single plate but, at the higher velocities, it was quite different . The implications regarding resonances in axial-flow compressors are discussed.