Abstract
Turbo-machineries have many kind of cavities or grooves on their surface and shapes of these cavities are not simple and some cavity emitted self excited aerodynamic tone, as called cavity tone, on some flow conditions. The purpose of this study is to make clear the detail mechanism of aerodynamic tone emitted from the self excited air flow around a deep cavity with acoustic resonance. We have studied experimentally the self excited air flow around a semi cylindrical cavity on the floor plate. Characteristics of this cavity tone and the flow pattern in the cavity were measured. Steady components of the secondary flow are decreased but unsteady flow components are excited at some portion in the cavity by the reasonance of tones. Turbulence distribute circumferentially on the front region and radially on the rear region in the cavity.
