Investigation on behaviors of acoustoelastic cavities using a novel reduced finite element–dual reciprocity boundary element formulation

Abstract

This paper presents the acoustic and structure characteristics of chambers with elastic/rigid baffles and elastic walls using a novel formulation. The acoustic fluid is assumed to be compressible and inviscid, and the effect of mean flow is neglected. The acoustic field is formulated based on the dual reciprocity boundary element method (DRBEM), and the finite element method (FEM) is used to model the structural dynamics of elastic walls. The reduced-order model (ROM) of the coupled system is derived based on modal analysis of the acoustic field with rigid boundaries and the structure in a vacuum. Numerical examples are presented, and the acoustic modes and frequencies of the chambers are determined by analysis of eigenvalues of the coupled governing equations. The accuracy of the introduced model, which is based on the reduced-order DRBEM-FEM formulation, is examined by comparing the results with analytical and numerical predictions reported in the literature, and good agreements are achieved. Besides, the effects of baffles are studied for different configurations and the elasticity of a wall in a combustion chamber is investigated.

Keywords

• acoustoelastic
• dual reciprocity boundary element method
• finite element method
• baffled structures