EFFECTS OF EDGE GEOMETRY ON FLOW PAST THE DEEP, CIRCULAR, AXISYMMETRIC CAVITY: ANALYSIS OF THE FIRST DIAMETRAL ACOUSTIC MODE

Abstract

In this paper, the phenomenon of aeroacoustic resonance due to the flow past a deep, circular, axisymmetric cavity with a depth much larger than its width or length is investigated. Several representative cases of the internal cavity geometry that involved chamfers of various lengths of the upstream and the downstream edges of the cavity, as well as a reference case with sharp, 90° edges were analyzed. The acoustic mode shapes, as well as the distribution of acoustic particle velocity, were reconstructed using the dynamic pressure data while the flow velocity in the vicinity of the cavity opening and distribution of the turbulent intensities, as well as shear stress over the cavity length, were measured using digital particle image velocimetry (PIV). This combined approach allowed to determine the effect of chamfered edges on acoustic response of the system, evolution of the cavity free shear layers, and on the azimuthal characteristics of the first acoustic diametral mode of the cavity.