Radiation from small acoustic sources located close to a submerged, compliantly coated cylindrical shell

Abstract

Measurements were made of the radiation from individual, small acoustic sources located close to a submerged, compliantly coated, thin cylindrical shell in the 1<ka<20 frequency range, where k is the acoustic wavenumber, and a is the radius of the coated cylinder. The behavior of the radiated pressure field is shown to have two distinct frequency regimes. For ka>5, the field is simple, and is well approximated by a source and its negative image. For ka<4, the pressure field is characterized by significant spatial variations, owing to contributions from the elastic response of the coated cylinder. Finite-element model results are compared with the measurements, and are used to provide insight into the interactions between the source and the coated shell. [Work supported by ONR.]