Sound Transmission Through Inhomogeneous Waveguides
Free (open access)
A T Peplow & S Finnveden
A spectral element method is described which enables reduced wave equation problems defined in regular, arbitrary length regions to be solved as a set of coupled problems over neighbouring domains. A combination of trial functions are considered, namely the specific eigenfunctions of a differential operator and a set of hierarchical polynomials. The coefficients in the representation of the acoustic pressure are obtained by imposing continuity across element interfaces and including the given boundary conditions. The former is satisfied implicitly via a variational principle. Accurate approximations are obtained for computations of sound transmission over a step-profile and local perturbations of the ambient fluid density.