A mode matching approach for modeling two dimensional porous grating with infinitely rigid or soft inclusions

Benoit Nennig (1) , Y. Renou (1) , J.-P. Groby (1) , Yves Aurégan (1)

1 LAUM - Laboratoire d'Acoustique de l'Université du Mans

This work investigates the acoustical properties of a multilayer porous material in which periodic inclusions are embedded. The material is assumed to be backed by a rigid wall. Most of the studies performed in this field used the multipole method and are limited to circular shape inclusions. Here, a mode matching approach, more convenient for a layered system, is adopted. The inclusions can be in the form of rigid scatterers of an arbitrary shape, in the form of an air-filled cavity or in the form of a porous medium with contrasting properties. The computational approach is validated on simple geometries against other numerical schemes and with experimental results obtained in an anechoic room on a rigid grating embedded in a porous material made of 2 mm glass beads. The method is used to study the acoustic absorption behavior of this class of materials in the low frequency range and at a range of angles of incidence.

Domaines: Acoustique [physics.class-ph]

Benoit Nennig, Y. Renou, J.-P. Groby, Yves Aurégan. A mode matching approach for modeling two dimensional porous grating with infinitely rigid or soft inclusions. Journal of the Acoustical Society of America, 2012, 131 (5), pp.3841-3852. ⟨10.1121/1.3693655⟩. ⟨hal-01179031⟩