Analysis and control of resonant cavity flows

Abstract

Recently, the trend for the internalisation of stores within an aircraft fuselage has led to a renewed interest in the field of cavity aero-acoustics. Many modern military aircraft, including recent unmanned combat configurations, are designed with internal stores carriage. Housing stores within a weapon bay cavity has the two fold benefit to the aircraft: reduced excrescence drag, and a smaller radar signature. However, open cavities exposed to a grazing flow can exhibit large resonant pressure fluctuations which may damage stores or components within the cavity. The aim of this research is to investigate the fundamental flow characteristics of open cavities and to develop passive palliative concepts to control the unsteady pressure fluctuations within resonant cavity flows. The fundamental flow characteristics of two scale cavities were investigated experimentally: a 1/40th scale model under transonic conditions (0.80