Numerical implementation and applications of a coupling algorithm for structural-acoustic models with unequal discretization and partially interfacing surfaces

The numerical implementation of a coupled finite element-boundary element a lgorithm for computing simultaneously the structural vibration and the asso ciated acoustic field and a complete set of validation and application data is presented. The new developments in the coupling algorithm presented in this paper are associated with a capability for unequal mesh density betwee n the structural and the acoustic model, division of both models into inter facing and non-interfacing zones, efficient computation of the coupling mat rices, and incorporation of acoustic multiple connection constraints in the coupling computations. Applications are identified in the area of launch v ehicle dynamics where a reverberant acoustic environment provides the excit ation for computing either noise transmitted through flexible structures, o r noise-induced vibration due to acoustic loads. Results and correlation to test data are presented for a. fairing and an expansion nozzle of a rocket . Numerical results are also compared to an analytical solution for noise t ransmitted through a flexible cavity backed plate. (C) 1999 Elsevier Scienc e B.V. All rights reserved.