Almeida, Gildean do N, Vergara, Erasmo F, Barbosa, Leandro R, Lenzi, Arcanjo and Birch, Robert S ORCID: 0000-0003-0861-5408
(2021)
A low-frequency sound absorber based on micro-slit and coiled cavity.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING, 43 (3).
124-.
Text
A low‑frequency sound absorber based on micro‑slit and coiled cavity.docx - Author Accepted Manuscript Download (1MB) |
Abstract
The design of a compact low-frequency acoustic absorber whose thickness is less than the operating frequency wavelength is a difficult challenge. However, recent developments in metamaterial engineering have enabled significant advances towards this goal. This paper presents an investigation of a low-frequency absorber (i.e., operating between 100 and 600 Hz) structured around a new concept of a thin cavity of coiled spaces coupled with a panel and micro-slit. The ability of this acoustic metamaterial absorber to control sound energy with increased relative bandwidth is examined analytically and numerically considering the viscous-thermal losses in both the micro-slit and coiled spaces. A prototype absorber was manufactured using advanced additive manufacturing technique and evaluated in an impedance tube apparatus. The experimental results showed the absorber capable of controlling 95% of the sound energy at 365 Hz with a relative bandwidth of 60.3%. These results compare well to those obtained from the analytical analysis and finite element method. Thus, the proposed acoustic absorber is shown to be capable of operating in the deep-subwavelength scale.
Item Type: | Article |
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Uncontrolled Keywords: | Low-frequency absorber, Coiled spaces, Acoustic metamaterial, Micro-slit, Visco-thermal effects |
Depositing User: | Symplectic Admin |
Date Deposited: | 04 Mar 2021 08:13 |
Last Modified: | 17 Mar 2024 11:21 |
DOI: | 10.1007/s40430-020-02763-y |
Related URLs: | |
URI: | https://livrepository.liverpool.ac.uk/id/eprint/3116452 |