Finite element study of acoustic waves

Abstract

The generation and propagation of small amplitude acoustic waves in a homogenous, loss-free, compressible fluid is studies by the finite element method. A diaphragm mounted in a semi-infinite rigid baffle generates acoustic waves in a semi-infinite fluid region. Steady-state pressure distribution is found for a hemispherical region with boundary reflection suppressed through use of a radiation condition. The computer program developed for the purpose utilizes iso-parametric finite elements with curvilinear boundaries. Incorporated in the program is a versatile mesh generator which minimizes the quantity of input data. Acceptable agreement with analytic results is obtained when there are at least four elements per wave-length.