Acoustic scattering by a cylindrical shell with symmetric line constraints in the heavy fluid-loading limit

Abstract

A cylindrical shell, modelled using Donnell-Mushtari thin shell theory, is reinforced by two internal rigid plates attached to the shell along lines parallel to the shell axis. A circumferential mode expansion is used to obtain numerical results for the scattered sound field due to the presence of the reaction forces along the attachment lines. In the heavy fluid-loading limit, which is appropriate for low and mid-frequency ranges for practical underwater structures, asymptotic analysis is presented which allows the peak frequencies in the scattered field due to the reaction forces to be expressed (to leading order) in terms of the geometry and the shell and fluid parameters. These predictions agree well with results obtained by numerically evaluating the infinite sums needed to calculate the reaction forces and hence the scattered field.