FINITE-ELEMENT ANALYSIS OF THE PROPAGATION OF ACOUSTIC-WAVES IN WAVE-GUIDES

A bidimensional mathematical model is developed to study the propagati on of acoustic waves in waveguides. First, the theoretical formulation is presented for the case of a linear waveguide. The problem is reduc ed to a bidimensional problem, where only the cross-section of the gui de is meshed by using finite elements. Then, the method is extended to the case of a circular waveguide of constant curvature. After the val idation of the method for simple cases, a wedge guide, the top angle o f which is variable, is studied, and the finite element results are co mpared to experimental ones, demonstrating the accuracy of the model. Finally, it is indicated how this approach could be extended to wavegu ides of any cross-section, for applications in signal processing devic es, in geophysics and underwater acoustics, as well as in solid surfac e physics. (C) 1996 Academic Press Limited