Benchmarking two simulation models for underwater and atmospheric sound propagation

Computational wave propagation models are widely used in underwater and atmospheric sound propagation simulation. In most realistic cases the physical domains involved are irregular. We have developed finite element techniques, applied to general irregular meshes and coupled with discrete, artificial absorbing boundary conditions of nonlocal type, for the Helmholtz equation and its ‘standard’ parabolic approximation. The physical domain is axially symmetric, with several fluid layers of variable acoustic properties. Boundaries and interfaces of general topography are allowed. The resulting models are referred to as the FENL and CNP1-NL models, respectively. We present results of the FENL model for underwater acoustic applications related to object identification and of the CNP1-NL for atmospheric sound propagation over an irregular terrain.