Microstructure based model for sound absorption predictions of perforated closed-cell metallic foams

F. Chevillotte (1) , C. Perrot (2) , R. Panneton (1)

1 GAUS - Groupe d'Acoustique de l'Université de Sherbrooke
2 MSME - Laboratoire de Modélisation et Simulation Multi Echelle

Closed-cell metallic foams are known for their rigidity, lightness, thermal conductivity as well as their low production cost compared to open-cell metallic foams. However, they are also poor sound absorbers. Similarly to a rigid solid, a method to enhance their sound absorption is to perforate them. This method has shown good preliminary results but has not yet been analyzed from a microstructure point of view. The objective of this work is to better understand how perforations interact with closed-cell foam microstructure and how it modifies the sound absorption of the foam. A simple two-dimensional microstructural model of the perforated closed-cell metallic foam is presented and numerically solved. A rough three-dimensional conversion of the two-dimensional results is proposed. The results obtained with the calculation method show that the perforated closed-cell foam behaves similarly to a perforated solid; however, its sound absorption is modulated by the foam microstructure, and most particularly by the diameters of both perforation and pore. A comparison with measurements demonstrates that the proposed calculation method yields realistic trends. Some design guides are also proposed. (C) 2010 Acoustical Society of America. [DOI: 10.1121/1.3473696]

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

F. Chevillotte, C. Perrot, R. Panneton. Microstructure based model for sound absorption predictions of perforated closed-cell metallic foams. Journal of the Acoustical Society of America, 2010, 128 (4), pp.1766--1776. ⟨10.1121/1.3473696⟩. ⟨hal-00692860⟩