On the role of resonance and thermoviscous losses in an implementation of “acoustic black hole” for sound absorption in air

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21230%2F22%3A00359147" target="_blank" >RIV/68407700:21230/22:00359147 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1016/j.wavemoti.2022.103039" target="_blank" >https://doi.org/10.1016/j.wavemoti.2022.103039</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.wavemoti.2022.103039" target="_blank" >10.1016/j.wavemoti.2022.103039</a>

Result language

angličtina

Original language name

On the role of resonance and thermoviscous losses in an implementation of “acoustic black hole” for sound absorption in air

Original language description

In this work, we propose a mathematical model of a sound-absorbing structure for anechoic duct termination, commonly called the acoustic black hole. The structure consists of a set of rigid rings separated by narrow fluid-filled cavities. There are holes in the centers of the rings, whose radii smoothly vary along the structure. According to the previously published works, wave speed in this structure can theoretically decrease to zero value, which results in the reduction of the reflection coefficient. The proposed model is based on the linearized Navier–Stokes equations formulated in 2D axisymmetric cylindrical coordinates, which are solved numerically in the frequency domain employing the finite element method. This way, thermoviscous losses in the acoustic boundary layer adjacent to the fluid–solid interfaces, especially in the narrow cavities, are accounted for properly. The numerical results show that the absorption of acoustic energy in this structure is connected with resonances taking place in the cavities forming annular resonators, rather than with the acoustic wave slow-down. This effect has not been captured in the previously published models. It is shown that the geometrical details of the structure strongly influence its behavior, indicating the possibility of its optimization to serve as an efficient absorber of acoustic energy in a relatively wide frequency range.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10307 - Acoustics

Project

<a href="/en/project/GA22-33896S" target="_blank" >GA22-33896S: Advanced methods of sound and elastic wave field control: acoustic black holes, metamaterials and functionally graded materials</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Wave Motion

ISSN

0165-2125

e-ISSN

1878-433X

Volume of the periodical

114

Issue of the periodical within the volume

103039

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

10

Pages from-to

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UT code for WoS article

000841594100006

EID of the result in the Scopus database

2-s2.0-85135899825