Vortex-Flow Frequency of Cavity Tone with Acoustic Resonance

Abstract

Understanding the vortex flow mechanism of cavity tones is desired to control tones in aeroacoustics field. With respect to cavity tones in deep cavity with acoustic resonances the mechanism of vortex flow has not been made clear enough. The vortex might flow out from the upstream side edge of the cavity when the circulation of the flow around this edge exceeds the predetermined value. Above phenomenon is the cause of the cavity tones. It would be the estimated mechanism that the particle velocity of the resonant sound wave influences on the limitation of circulation around the upstream edge for releasing a vortex from the edge. And more, the feedback disturbance charges the vortex circulation. As a result of trial and error by simple numerical calculation, it became possible to explain the phenomenon of cavity tones with resonance by some assumption mechanism.