Acoustic radiation from a simple structure in supersonic flow

It is well established that fluid flow can have significant effects on structural acoustic behavior, as is the fact that induced coupling between discrete modes of vibration becomes significant as flow velocity increases. To date, work in this area has been confined to subsonic flows, with the effects on sound radiation efficiency and sound power radiation quantified and compared for various subsonic flow speeds. The purpose of this work is to study the effects that supersonic flow has on these structural acoustic phenomena, along with an investigation of the uncoupled behavior of single modes in the transonic region. Theoretical development of the equations governing the vibration of a simply supported plate in an infinite baffle and an aerodynamic system that models a semi infinite flowing medium along with the method for coupling these systems is included. Computational results are presented illustrating the behavior of the uncoupled modes in the transonic region and the uncoupled and coupled effects on the structural response and Sound power radiation as well as a study of the radiation efficiency of the Coupled system. (c) 2009 Elsevier Ltd. All rights reserved.