Scattering from a finite cylinder near an interface

Abstract

In this paper, a Boundary Integral Equation Method (BIEM) is described for the computation of scattering from a finite, rigid, cylinder near a pressure release interface. The cylinder lies parallel or tilted with respect to the interface plane so that the azimuthal symmetry of the problem is destroyed. The scattering solution is first described in terms of an azimuthally symmetric free space solution. The multiple interactions of the scattered field with the interface are accounted for by an azimuthal-conversion matrix. In Sec. III, the method of this paper is benchmarked using wavefield superposition for a sphere near a pressure-release surface. Computed scattered spectra are shown for a finite cylinder, parallel and tilted with respect to the interface, and for a variety of source/receiver geometries. The differences resulting from not including multiple target/interface interactions (single scatter solution) and from including all interactions are presented. The problem of irregular frequencies for the single-scatter and the fully coupled BIEM are discussed and numerically examined.

Rayleigh scattering of a cylindrical sound wave by an infinite cylinder

“…Using condition (21), the derivative relationships defined in Eq. (17), and substitution of Eqs. (13)- (16) into Eq.…”

“…[1][2][3][4][5] However, knowledge of the full Green's functions is necessary for many problems of current interest for which the physical spacing between the scatterers themselves or the scatterers' separation from a source or boundary is comparable to their size. In underwater acoustics, such problems can arise in dense multi-scatterer configurations, 6 radiation by finite sources, [7][8][9][10] target classification, [11][12][13] source localization, 14 scattering suppression, 15,16 and when calculating the radiation and scattering of sound due to objects located near the ocean surface 17,18 or the seafloor. [19][20][21] No simple analytic solutions are readily available for such problems, and numerical methods have to be used.…”