Identification of the Cold Flow Perturbation Sources in a Dump Combustor With a Tapered Exit

Abstract

This paper reports on the experimental investigation of the flow inside a low aspect ratio (length less than the reattachment length of separated flow) dump combustor with a tapered exit. The flow field in the combustor is evaluated using wall pressure and velocity measurements at varying flow Reynolds numbers. The mean velocity and turbulence variation closer to the wall of the combustor was found to be different from that at other radial locations due to the presence of recirculation and possible thickening of the shear layer caused by a decrease in the strength of the potential core. The power spectral study of the wall pressure and velocity fluctuations suggested the dominant presence of acoustic perturbations with amplitude modulation of such perturbations due to viscous dissipation in the shear layer.