Acoustical properties of air-saturated porous material
with periodically distributed dead-end pores

Leclaire, P; Umnova, O; Dupont, T; Panetton, R

Abstract

A theoretical and numerical study of the sound propagation in air-saturated porous media with
straight main pores bearing lateral cavities (dead-ends) is presented. The lateral cavities are located
at “nodes” periodically spaced along each main pore. The effect of periodicity in the distribution of
the lateral cavities is studied, and the low frequency limit valid for the closely spaced dead-ends is
considered separately. It is shown that the absorption coefficient and transmission loss are influenced
by the viscous and thermal losses in the main pores as well as their perforation rate. The presence
of long or short dead-ends significantly alters the acoustical properties of the material and can
increase significantly the absorption at low frequencies (a few hundred hertz). These depend
strongly on the geometry (diameter and length) of the dead-ends, on their number per node, and on
the periodicity along the propagation axis. These effects are primarily due to low sound speed in
the main pores and to thermal losses in the dead-end pores. The model predictions are compared
with experimental results. Possible designs of materials of a few cm thicknesses displaying
enhanced low frequency absorption at a few hundred hertz are proposed.

Citation

with periodically distributed dead-end pores. ˜The œJournal of the Acoustical Society of America (Online), 137(4), 1772-1782. https://doi.org/10.1121/1.4916712

• Journal Article Type: Article
• Acceptance Date: Mar 23, 2015
• Online Publication Date: Apr 27, 2015
• Publication Date: Apr 27, 2015
• Deposit Date: May 20, 2015
• Publicly Available Date: Apr 5, 2016
• Journal: The Journal of the Acoustical Society of America (JASA)
• Print ISSN: 0001-4966
• Peer Reviewed: Peer Reviewed
• Volume: 137
• Issue: 4
• Pages: 1772-1782
• DOI: https://doi.org/10.1121/1.4916712.
• Publisher URL: http://dx.doi.org/ 10.1121/1.4916712
• Related Public URLs: http://scitation.aip.org/content/asa/journal/jasa
• Additional Information: Funders : Universite du Burgogne