SOUND RADIATION FROM A PLATE INTO A POROUS MEDIUM

A nearby layer of porous sound-absorbing material has previously been shown to be capable of greatly increasing the acoustic power radiated from a vibrating flat plate, and consequently of enhancing the structural damping in the plate. In this paper, a previously published model for sound radiation from a plate of infinite extent, radiating into a semi-infinite region of absorbent, is extended to allow for a finite air gap between absorbent and plate, as well as a finite absorbent thickness. Limited parametric studies are presented here for typical cases, and model predictions are compared to finite-plate predictions and to measured data. It is concluded that the infinite-plate model can be a useful design tool, presenting minimal computational demands.