On mechanism of self-oscillatory interaction of plane subsonic jet with acoustic resonator

The interaction of a plane subsonic jet with an acoustic Helmholtz resonator is considered. Visualization of the flow pattern is conducted using a schlieren technique. Oscillations of pressure in the resonator cavity are measured. The dependence of frequency and amplitude of oscillations on the jet velocity is analyzed. A simple closed model of the self-oscillatory process is developed that makes it possible to calculate the frequency and amplitude of the self-oscillations and to determine the intervals within which induction of the proper mode of oscillation occurs. It is shown that the finite amplitude of oscillation is determined primarily by a convolution of vortices in the jet.