DOUBLY ASYMPTOTIC APPROXIMATIONS FOR SUBMERGED STRUCTURES WITH INTERNAL FLUID VOLUMES - FORMULATION

Doubly asymptotic approximations (DAAs) are approximate temporal imped ance relations for a medium in contact with a flexible body. In this p aper, the method of operator matching previously used for external aco ustic domains is used to develop first- and second-order boundary inte gral DAAs for internal acoustic domains. Corresponding boundary elemen t forms permit The numerical solution of transient structural acoustic s problems with complex geometry. The accuracy of the DAAs is assessed in the following companion paper by comparing DAA and exact solutions for a canonical problem with spherical geometry.