Radiation efficiency of convected fluid-loaded plate.

The radiation of sound from geometrically simple vibrating structures into stationary fluids is well understood. However, to date, very few investigations have considered the effects of fluid convection on structural acoustic radiation. The purpose of this investigation is to quantify the effects that fluid flow has on the sound radiated from rectangular vibrating plates. The discussion includes a description of the fundamental physics associated with a simply supported, vibrating, rectangular plate imbedded in an infinite baffle and radiating into a semi-infinite convected fluid field. This is followed by a discussion of the computational approach used to calculate the plate radiation efficiency. Finally, numerical results are presented which demonstrate the effect that convection has on the radiation efficiency. The primary effect is a significant increase in radiation efficiency in the mid-wave number region, which is attributable to an effective decrease in the critical frequency.