%0 Journal Article
%T Enhancing the absorption coefficient of a backed rigid frame porous layer by embedding circular periodic inclusions
%+ Laboratoire d'Acoustique de l'Université du Mans (LAUM)
%+ Huntsman Europe, Everslaan 45, 3078 Everberg, Belgium
%+ Laboratory of Acoustics and Thermal Physics, K.U. Leuven
%A Groby, J.-P.
%A Dazel, Olivier
%A Duclos, Aroune
%A Boeckx, L.
%A Kelders, L.
%< avec comité de lecture
%@ 0001-4966
%J Journal of the Acoustical Society of America
%I Acoustical Society of America
%V 130
%N 6
%P 3771-3780
%8 2011-12
%D 2011
%R 10.1121/1.3652865
%K Phononic crystal
%K Bloch wave
%K Gratings
%K Finite-element analysis
%K Geometrical optics
%K Vector fields
%K Optical absorption
%K Acoustical properties
%K Wave mechanics
%K Speed of sound
%Z Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]Journal articles
%X The acoustic properties of a porous sheet of medium static air flow resistivity (around 10 000Nms-4), in which a periodic set of circular inclusions is embedded and which is backed by a rigid plate, are investigated. The inclusions and porous skeleton are assumed motionless. Such a structure behaves like a multi-component diffraction grating. Numerical results show that this structure presents a quasi-total (close to unity) absorption peak below the quarter-wavelength resonance of the porous sheet in absence of inclusions. This result is explained by the excitation of a complex trapped mode. When more than one inclusion per spatial period is considered, additional quasi-total absorption peaks are observed. The numerical results, as calculated with the help of the mode-matching method described in this paper, agree with those calculated using a finite element method.
%G English
%L hal-02458855
%U https://hal-univ-lemans.archives-ouvertes.fr/hal-02458855
%~ CNRS
%~ UNIV-LEMANS
%~ LAUM