Cargando…

Rainbow-trapping absorbers: Broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems

Perfect, broadband and asymmetric sound absorption is theoretically, numerically and experimentally reported by using subwavelength thickness panels in a transmission problem. The panels are composed of a periodic array of varying crosssection waveguides, each of them being loaded by Helmholtz reson...

Descripción completa

Detalles Bibliográficos
Autores principales: Jiménez, Noé, Romero-García, Vicent, Pagneux, Vincent, Groby, Jean-Philippe
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5648927/
https://www.ncbi.nlm.nih.gov/pubmed/29051627
http://dx.doi.org/10.1038/s41598-017-13706-4
_version_ 1783272468770717696
author Jiménez, Noé
Romero-García, Vicent
Pagneux, Vincent
Groby, Jean-Philippe
author_facet Jiménez, Noé
Romero-García, Vicent
Pagneux, Vincent
Groby, Jean-Philippe
author_sort Jiménez, Noé
collection PubMed
description Perfect, broadband and asymmetric sound absorption is theoretically, numerically and experimentally reported by using subwavelength thickness panels in a transmission problem. The panels are composed of a periodic array of varying crosssection waveguides, each of them being loaded by Helmholtz resonators (HRs) with graded dimensions. The low cut-off frequency of the absorption band is fixed by the resonance frequency of the deepest HR, that reduces drastically the transmission. The preceding HR is designed with a slightly higher resonance frequency with a geometry that allows the impedance matching to the surrounding medium. Therefore, reflection vanishes and the structure is critically coupled. This results in perfect sound absorption at a single frequency. We report perfect absorption at 300 Hz for a structure whose thickness is 40 times smaller than the wavelength. Moreover, this process is repeated by adding HRs to the waveguide, each of them with a higher resonance frequency than the preceding one. Using this frequency cascade effect, we report quasi-perfect sound absorption over almost two frequency octaves ranging from 300 to 1000 Hz for a panel composed of 9 resonators with a total thickness of 11 cm, i.e., 10 times smaller than the wavelength at 300 Hz.
format Online
Article
Text
id pubmed-5648927
institution National Center for Biotechnology Information
language English
publishDate 2017
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-56489272017-10-26 Rainbow-trapping absorbers: Broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems Jiménez, Noé Romero-García, Vicent Pagneux, Vincent Groby, Jean-Philippe Sci Rep Article Perfect, broadband and asymmetric sound absorption is theoretically, numerically and experimentally reported by using subwavelength thickness panels in a transmission problem. The panels are composed of a periodic array of varying crosssection waveguides, each of them being loaded by Helmholtz resonators (HRs) with graded dimensions. The low cut-off frequency of the absorption band is fixed by the resonance frequency of the deepest HR, that reduces drastically the transmission. The preceding HR is designed with a slightly higher resonance frequency with a geometry that allows the impedance matching to the surrounding medium. Therefore, reflection vanishes and the structure is critically coupled. This results in perfect sound absorption at a single frequency. We report perfect absorption at 300 Hz for a structure whose thickness is 40 times smaller than the wavelength. Moreover, this process is repeated by adding HRs to the waveguide, each of them with a higher resonance frequency than the preceding one. Using this frequency cascade effect, we report quasi-perfect sound absorption over almost two frequency octaves ranging from 300 to 1000 Hz for a panel composed of 9 resonators with a total thickness of 11 cm, i.e., 10 times smaller than the wavelength at 300 Hz. Nature Publishing Group UK 2017-10-19 /pmc/articles/PMC5648927/ /pubmed/29051627 http://dx.doi.org/10.1038/s41598-017-13706-4 Text en © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Jiménez, Noé
Romero-García, Vicent
Pagneux, Vincent
Groby, Jean-Philippe
Rainbow-trapping absorbers: Broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems
title Rainbow-trapping absorbers: Broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems
title_full Rainbow-trapping absorbers: Broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems
title_fullStr Rainbow-trapping absorbers: Broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems
title_full_unstemmed Rainbow-trapping absorbers: Broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems
title_short Rainbow-trapping absorbers: Broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems
title_sort rainbow-trapping absorbers: broadband, perfect and asymmetric sound absorption by subwavelength panels for transmission problems
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5648927/
https://www.ncbi.nlm.nih.gov/pubmed/29051627
http://dx.doi.org/10.1038/s41598-017-13706-4
work_keys_str_mv AT jimeneznoe rainbowtrappingabsorbersbroadbandperfectandasymmetricsoundabsorptionbysubwavelengthpanelsfortransmissionproblems
AT romerogarciavicent rainbowtrappingabsorbersbroadbandperfectandasymmetricsoundabsorptionbysubwavelengthpanelsfortransmissionproblems
AT pagneuxvincent rainbowtrappingabsorbersbroadbandperfectandasymmetricsoundabsorptionbysubwavelengthpanelsfortransmissionproblems
AT grobyjeanphilippe rainbowtrappingabsorbersbroadbandperfectandasymmetricsoundabsorptionbysubwavelengthpanelsfortransmissionproblems