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

Mosa, Ali Ibrahim and Jameel, Esraa Al-Amer and Ramlan, Roszaidi and Putra, Azma (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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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:	Double-layer micro-perforated panel, Inhomogeneous MPP, Absorption coefficient, Multi cavity depth Acoustics
Divisions:	Faculty of Mechanical Engineering
Depositing User:	Norfaradilla Idayu Ab. Ghafar
Date Deposited:	07 Aug 2020 10:03
Last Modified:	21 Jul 2023 11:46
URI:	http://eprints.utem.edu.my/id/eprint/24188
Statistic Details:	View Download Statistic

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