Extraordinary absorption of sound in porous lamella-crystals

We present the design of a structured material supporting complete absorption of sound with a broadband response and functional for any direction of incident radiation. The structure which is fabricated out of porous lamellas is arranged into a low-density crystal and backed by a reflecting support....

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Bibliographic Details
Authors: Christensen, Johan, Romero García, Vicente, Garcia de Abajo, Francisco Javier, Mortensen, N. A., Willatzen, M., Picó Vila, Rubén|||0000-0003-3537-9658, Cebrecos, Alejandro|||0000-0001-8790-8668, Sánchez Morcillo, Víctor José|||0000-0003-4766-1263
Format: article
Publication Date:2014
Country:España
Institution:Universitat Politècnica de València (UPV)
Repository:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Language:English
OAI Identifier:oai:riunet.upv.es:10251/62099
Online Access:https://riunet.upv.es/handle/10251/62099
Access Level:Open access
Keyword:Porous media
Periodic structures
Lamella
Sonic crystals
Absorption
Sound
FISICA APLICADA
Description
Summary:We present the design of a structured material supporting complete absorption of sound with a broadband response and functional for any direction of incident radiation. The structure which is fabricated out of porous lamellas is arranged into a low-density crystal and backed by a reflecting support. Experimental measurements show that strong all-angle sound absorption with almost zero reflectance takes place for a frequency range exceeding two octaves. We demonstrate that lowering the crystal filling fraction increases the wave interaction time and is responsible for the enhancement of intrinsic material dissipation, making the system more absorptive with less material.