Analysis of a Three Dimensional Sound Field by Using The Boundary Element Method : 3rd Report, An Analysis Method Based on the Transfer Matrix Theory and Its Application to Sound Field Analysis of a Large Silencer for Eliminating Pulsation

Abstract

A highly efficient method for three-dimensional analysis of the acoustical characteristics of a silencer is proposed. This method enables a sound field to be analyzed by combining new three dimensional transfer matrices derived by using the boundary element method (BEM) with one dimensional transfer matrices for plane wave propagations. Results obtained through the new proposed method agreed well with results of the finite element method (FEM) and with those of the plane-wave theory in the frequency region where plane-wave propagation can be assumed. The spacial distribution of pulsation pressure in a large silencer which was installed on the discharge side was measured. These measured data are compared with the computation results to show the good accuracy of this method. This method requires much less time than is needed for the BEM and the FEM.