Foundamental Study on Effectiveness of Noise Reduction Mechanisms Installed around Opening of Enclosure

Abstract

It has been available that the most of sound energy generated by machines would be radiated to atmosphere through the opening of an enclosure of a machine and it would be effective for proofing noise to control it. Then, in this paper, the methods to control the sound energy radiated through the opening of an enclosure are studied. That is, two kinds of mechanism, plate type and box type, to control the sound energy have been proposed from the point of view to arrest and dissipate the sound energy. The proto-type models of these mechanisms are fabricated and tested for evaluating theire effectiveness. After evaluation, the foundamental data to design the proposed mechanisms have been obtained by numerical simulations using BEM.