From Micro-Perforates to Micro-Capillary Absorbers: Analysis of Their Broadband Absorption Performance through Modeling and Experiments
A challenging issue is currently the design of non-fibrous ultra-thin acoustic absorbers that are able to provide broadband performance in demanding environments. The objective of this study is to compare using simulations and measurements the broadband absorption performance of highly porous micro-...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/13/19/10844 |
| _version_ | 1797576180534083584 |
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| author | Cédric Maury Teresa Bravo |
| author_facet | Cédric Maury Teresa Bravo |
| author_sort | Cédric Maury |
| collection | DOAJ |
| description | A challenging issue is currently the design of non-fibrous ultra-thin acoustic absorbers that are able to provide broadband performance in demanding environments. The objective of this study is to compare using simulations and measurements the broadband absorption performance of highly porous micro-capillary plates (MCPs) to that of micro-perforated panels (MPPs) under normal incidence while considering unbacked or backed configurations. MCPs are unusual materials used for sound absorption with micron-sized channels and a high perforation ratio. Impedance-based modeling and Kundt tube experiments show that MCPs with suitable channel diameters have a pure constant resistance that outperforms the acoustic efficiency of MPP absorbers. Unbacked MCPs exhibit a controllable amount of high absorption that can exceed 0.8 over more than five octaves starting from 80 Hz, thereby achieving a highly sub-wavelength absorber. MCPs still provide broadband high absorption when backed by a rigid cavity. Their bandwidth-to-thickness ratio increases toward its causal limit when the cavity depth decreases. A parallel MCP resonant absorber partly backed by closed and open cavities is proposed. Such MCP-based absorbers could serve as short anechoic terminations for the characterization of acoustic materials at low frequencies. |
| first_indexed | 2024-03-10T21:49:34Z |
| format | Article |
| id | doaj.art-6602b7e175fa4564b98118fa14e25063 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T21:49:34Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-6602b7e175fa4564b98118fa14e250632023-11-19T14:04:58ZengMDPI AGApplied Sciences2076-34172023-09-0113191084410.3390/app131910844From Micro-Perforates to Micro-Capillary Absorbers: Analysis of Their Broadband Absorption Performance through Modeling and ExperimentsCédric Maury0Teresa Bravo1Laboratoire de Mécanique et d’Acoustique (UMR), Centrale Marseille, Aix Marseille University, CNRS, 38 rue Frédéric Joliot-Curie, 13013 Marseille, FranceInstituto de Tecnologías Físicas y de la Información (ITEFI), Consejo Superior de Investigaciones Científicas (CSIC), Serrano 144, 28006 Madrid, SpainA challenging issue is currently the design of non-fibrous ultra-thin acoustic absorbers that are able to provide broadband performance in demanding environments. The objective of this study is to compare using simulations and measurements the broadband absorption performance of highly porous micro-capillary plates (MCPs) to that of micro-perforated panels (MPPs) under normal incidence while considering unbacked or backed configurations. MCPs are unusual materials used for sound absorption with micron-sized channels and a high perforation ratio. Impedance-based modeling and Kundt tube experiments show that MCPs with suitable channel diameters have a pure constant resistance that outperforms the acoustic efficiency of MPP absorbers. Unbacked MCPs exhibit a controllable amount of high absorption that can exceed 0.8 over more than five octaves starting from 80 Hz, thereby achieving a highly sub-wavelength absorber. MCPs still provide broadband high absorption when backed by a rigid cavity. Their bandwidth-to-thickness ratio increases toward its causal limit when the cavity depth decreases. A parallel MCP resonant absorber partly backed by closed and open cavities is proposed. Such MCP-based absorbers could serve as short anechoic terminations for the characterization of acoustic materials at low frequencies.https://www.mdpi.com/2076-3417/13/19/10844sound absorptionmicro-perforated panelsmicro-capillariesanechoic termination |
| spellingShingle | Cédric Maury Teresa Bravo From Micro-Perforates to Micro-Capillary Absorbers: Analysis of Their Broadband Absorption Performance through Modeling and Experiments Applied Sciences sound absorption micro-perforated panels micro-capillaries anechoic termination |
| title | From Micro-Perforates to Micro-Capillary Absorbers: Analysis of Their Broadband Absorption Performance through Modeling and Experiments |
| title_full | From Micro-Perforates to Micro-Capillary Absorbers: Analysis of Their Broadband Absorption Performance through Modeling and Experiments |
| title_fullStr | From Micro-Perforates to Micro-Capillary Absorbers: Analysis of Their Broadband Absorption Performance through Modeling and Experiments |
| title_full_unstemmed | From Micro-Perforates to Micro-Capillary Absorbers: Analysis of Their Broadband Absorption Performance through Modeling and Experiments |
| title_short | From Micro-Perforates to Micro-Capillary Absorbers: Analysis of Their Broadband Absorption Performance through Modeling and Experiments |
| title_sort | from micro perforates to micro capillary absorbers analysis of their broadband absorption performance through modeling and experiments |
| topic | sound absorption micro-perforated panels micro-capillaries anechoic termination |
| url | https://www.mdpi.com/2076-3417/13/19/10844 |
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