Absorption coefficient of a double-layer inhomogeneous micro-perforated panel backed with multiple cavity depths

Mosa, Ali Ibrahim and Putra, Azma and Jameel, Esraa Al-Amer and Ramlan, Roszaidi (2020) Absorption coefficient of a double-layer inhomogeneous micro-perforated panel backed with multiple cavity depths. ACOUSTICS AUSTRALIA, 48 (1). pp. 69-78. ISSN 0814-6039

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Official URL: https://link.springer.com/article/10.1007/s40857-0...

Abstract

Double-layer micro-perforated panels (MPPs) have been studied extensively as sound absorption systems to increase the absorption performance of single-layer MPPs. However, existing proposed models indicate that there is still room for improvement regarding the frequency bands of absorption for the double-layer MPP. This study presents a double-layer MPP formed with two single MPPs with inhomogeneous perforation backed by multiple cavities of varying depths. The theoretical formulation is developed using the electrical equivalent circuit method to calculate the absorption coefficient under a normal incident sound. The simulation results show that the proposed model can produce absorption coefficient with wider absorption bandwidth compared with the conventional double- and even triple-layer MPPs. The bandwidth can be increased to higher frequency by decreasing the cavity depth behind a sub-MPP with small hole diameter and a high perforation ratio, and to lower frequency by increasing the cavity depth behind a sub-MPP with large hole diameter and a small perforation ratio. The experimental data, measured by impedance tube, are in good agreement with the predicted results.

Item Type:	Article
Uncontrolled Keywords:	Absorption coefficient, Acoustics, Double-layer micro-perforated panel, Inhomogeneous MPP, Multi cavity depth
Divisions:	Faculty of Manufacturing Engineering
Depositing User:	Sabariah Ismail
Date Deposited:	29 Jul 2020 16:36
Last Modified:	21 Jul 2023 11:39
URI:	http://eprints.utem.edu.my/id/eprint/24189
Statistic Details:	View Download Statistic

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