Application of a multi-sector parabolic equation approach to compute acoustic scattering by non-canonically shaped impenetrable objects

Abstract

While parabolic equation (PE) methods have seen great use in ocean acoustic waveguide propagation, it is not as widely known that a multi-sector PE method, originally proposed by Levy and Zaporozhets [J. Acoust. Soc. Am. 103, 735–741 (1998)], can be applied to compute the scattered field about an object. Previous work was only able to benchmark the method with canonical geometries. In this talk, we demonstrate favorable agreement between free-field PE-based and finite-element based computations, the latter being taken as a benchmark, in two and three dimensions for non-canonically shaped impenetrable objects. Run-time scaling comparisons are also presented, which demonstrate the great advantage of the PE method in the high-frequency limit when a target is several or more wavelengths long. We also show how wide-angle PE and multiple-scattering corrections can be incorporated to treat concave scatterers. [Work sponsored by the Office of Naval Research.]While parabolic equation (PE) methods have seen great use in ocean acoustic waveguide propagation, it is not as widely known that a multi-sector PE method, originally proposed by Levy and Zaporozhets [J. Acoust. Soc. Am. 103, 735–741 (1998)], can be applied to compute the scattered field about an object. Previous work was only able to benchmark the method with canonical geometries. In this talk, we demonstrate favorable agreement between free-field PE-based and finite-element based computations, the latter being taken as a benchmark, in two and three dimensions for non-canonically shaped impenetrable objects. Run-time scaling comparisons are also presented, which demonstrate the great advantage of the PE method in the high-frequency limit when a target is several or more wavelengths long. We also show how wide-angle PE and multiple-scattering corrections can be incorporated to treat concave scatterers. [Work sponsored by the Office of Naval Research.]