A hybrid SEA/image sources approach for the prediction of the insertion loss of enclosures

Abstract

Acoustics 08 Paris 5545Enclosures are a classical solution to reduce the sound exposure of workers to the noise radiated by machinery. Their acoustic design can be achieved with the help of predictive tools based on simple analytical tools or sophisticated numerical deterministic models. However, there is no simple and fast tool allowing to account for the complexity of the enclosure configuration, capable of better simulating the non-diffuse nature of the field inside the enclosure and covering the typical frequency range [100Hz; 5000Hz]. This paper presents the development of such a tool for the prediction of the acoustic performance of enclosures. It is based on a hybrid model: the statistical energy analysis (SEA) for the sound transmission across the various elements of the enclosure and the method of image sources for the sound field inside the enclosure. The approach is validated by comparing calculation and experimental results carried out in a semi-anechoic room on rectangular and L-shape enclosures for several inner source locations. The effect of an opening is also investigated. The comparisons between the models and the experimental results show a good agreement for most of the tested configurations.