1University of Exeter (Mail Room, The Old Library
Prince of Wales Road
Exeter, Devon UK
EX4 4SB - United Kingdom)
2Roberval - Roberval (Université de Technologie de Compiègne - Centre de Recherche de Royallieu - rue du Docteur Schweitzer- CS 60319 - 60203 COMPIEGNE Cedex - France)
UTC - Université de Technologie de Compiègne (Université de Technologie de Compiègne - Centre de Recherche de Royallieu - rue du Docteur Schweitzer- CS 60319 - 60203 COMPIEGNE Cedex - France)
Abstract : Sound attenuation performances of a duct silencer made of a metamaterial composed of a set of poroelastic lamellas, are investigated numerically and experimentally. The lamella arrangement is designed so that skeleton elastic resonances appear at low frequency. In addition, the air gap between the lamellas induces pressure diffusion effects commonly encountered in highly contrasted double porosity media. The configuration of the silencer also exhibits strong anisotropy. A 3D finite element model of the silencer has been developed in order to identify the different mechanisms taking place in the silencer. Numerical results are shown to match well with experimental data for different lamella orientations. By exploiting the geometrical periodicity of the silencer, a Bloch waves analysis is realized and a parametric study is conducted. This reveals strong model dispersion and interaction due to lamella elastic resonances. It is shown that certain design parameters can be tuned in order to achieve large attenuation and absorption at low frequency.
https://hal.archives-ouvertes.fr/hal-03240280 Contributor : Claude InserraConnect in order to contact the contributor Submitted on : Sunday, May 30, 2021 - 1:35:22 PM Last modification on : Thursday, May 5, 2022 - 3:17:31 AM Long-term archiving on: : Tuesday, August 31, 2021 - 6:07:34 PM
Ke Li, Nicolas Dauchez, Benoit Nennig, Emmanuel Perrey-Debain. Metamaterial made of poroelastic lamellas for sound attenuation in duct. Forum Acusticum, Dec 2020, Lyon, France. pp.3-4, ⟨10.48465/fa.2020.0523⟩. ⟨hal-03240280⟩