New Variational Techniques for Acoustic Radiation and Scattering From ElasticShell Structures

摘要

The interaction between a vibrating submerged structure and the surroundingfluid, which features coupling between the surface pressure distribution and the structural displacement, is an inherent feature for sound radiation and target strength analyses. A variety of approaches have been implemented in the past, but each suffers from serious limitations. Formal mathematical analysis using separation of variables or integral transform techniques is suitable only for the simplest structural models, while full finite element descriptions of realistic structures and the surrounding medium lead to excessively large computer simulations. One approach uses approximate impedance-type boundary condition of uncertain accuracy to model the fluid response. Boundary element formulations rationally represent the interaction phenomena without explicitly solving field equations for the fluid, at the expense of an enormous increase in computational effort due to the need to cover the surface with a reasonably fine mesh.