On the Use of the Wave Based Technique for a Three-Dimensional Noise Radiation Analysis of Coupled Vibro-Acoustic Problems 2011-01-1713

Driven by both the ever more restrictive legal regulations on human exposure to noise and the growing customers' expectations regarding the functional performance of a product, the vibro-acoustic behaviour of the product have gained a significant importance over the last decades. At the same time, product development phase and costs have been reduced in order to comply with the nature of competitive market. To cope with those conflicting design targets, the computer aided engineering (CAE) became an essential part of the product design process.

A broad class of engineering vibro-acoustic problems involves the mutual coupling interaction between the structure and fluid. In this type of problem, the back-coupling effects are no longer negligible and the problem has to be considered as a fully coupled system. The conventional state-of-the-art techniques adopt the element-based schemes, such as the finite (FEM), boundary (BEM) and infinite element method (I-FEM). The inherent non-symmetric nature of a coupled system, however, compromises the computational efficiency of the uncoupled sparse solvers, mainly due to the high bandwidth of the system matrices. As a result, the practical applicability of these methods is restricted for a limited frequency range. Application of these techniques above the problem-specific frequency limit yields prohibitively large numerical models, which involve a huge amount of computational resources and are thus less efficient.

The presented paper discusses the concept and application of the Wave Based Technique (WBT) for the analysis of three-dimensional fully coupled vibro-acoustic problems involving unbounded acoustic domains. In this type of formulation both the structural thin plate bending problem and the unbounded acoustic problem are described by means of a coupled wave based model. The both parts of the coupled problem are solved simultaneously in order to account for the strong coupling interaction. The application of the proposed approach to various validation examples demonstrates its enhanced computational efficiency compared to state-of-the-art techniques.