Time-harmonic Analytic Solution for an Acoustic Plane Wave Scattering off an Isotropic Poroelastic Cylinder: Convergence and Form Function

Abstract

The scattering of a plane wave incident obliquely upon an infinite poroelastic cylinder immersed in inviscid fluid is investigated in this paper. Convergence analysis of the series expansion of the solutions for various interface conditions is conducted and it provides a priori estimates on number of terms necessary for achieving a desired accuracy. In contrast to the existing results in the literature, we consider viscous pore fluid and arbitrary interface discharge efficiency ηd. Moreover, the approach presented here does not require any restriction on the viscodynamic operator of the poroelastic equations and hence it can handle general cases beyond the dissipation models proposed by Biot and by Johnson, Koplik and Dashen. The back scattering form function is then calculated from the coefficients of the series solution. Numerical results with various incident angles and interface discharge efficiencies are also presented in this paper.