Numerical Model of the Insertion Loss Promoted by the Enclosure of a Sound Source

G. F. Greco [1], I. K. S. Hermont [1], B. P. Murta [1], T. B. Romero [1], P. H. Mareze [1], A. Lenzi [2], J. A. Cordioli [2],
[1] Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
[2] Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
Published in 2015

This study aims to develop and validate a finite element numerical model to represent the Insertion Loss (IL) promoted by the enclosure of a sound source. For the validation, a enclosure prototype was built in wood and the IL was measured in laboratory. The idea is to develop an efficient numerical model that would be suitable for enclosure's design and optimization.

The problem was modeled using two different approaches. First, the Pressure Acoustics, Frequency Domain interface was used to model the sound source, over a finite circular baffle, radiating in a free field condition. The second model includes the enclosure, using the Acoustic-Shell Interface, Frequency Domain to couple the structural and acoustic domains. Both 3D models were set in COMSOL Multiphysics software and have in common the basic geometry, sound source and mesh discretization. The numerical model provided a good estimation of the IL behavior. However, the improvement of this model is still possible since more representative boundary conditions and material properties could lead to a better agreement between experimental and numerical IL’ s curves.