Wet Modes of Submerged Structures—Part 1: Theory

A method for determining the acoustic radiation and scattering response induced by harmonic excitation of a submerged elastic structure is presented. It is based on expansion vectors, called wet modes, which are the vector components of the spatial part of free harmonic vibration at the forcing frequency of the fluid-structure system. Advantages of this formulation are suggested. Numerical results for a spherical shell obtained by this method are compared with those from a series solution and with methods based on the use of in-vacuo structural modes as expansion vectors. An in-depth study of the application of the methodology to a more complex submerged structure is presented in the companion paper (Daddazio et al., 1992).