Analysis of the multilayer microperforated panel for enhanced noise absorption using numerical and experimental approaches

The micro-perforated panel (MPP) is a lightweight, clean, and tunable noise absorber. Its sound absorption performance depends on several critical geometric parameters, including the diameter of the minute holes, the thickness of the panel where the holes are set, the hole perforation ratio, and the thickness of the air layer that forms the MPP cavity. Although sound absorption performance can be enhanced by aggregating multiple MPPs to form so-called multi-layer MPPs, identifying the optimal geometric parameters for all layers remains challenging due to the intricate mechanisms of sound wave propagation within the multi-layer MPPs. To gain an in-depth understanding of effective multi-layer MPP design, in this research, a parametric analysis over the entire design space is implemented to quantify the importance of these geometric parameters on sound absorption performance. Specifically, a high-fidelity numerical model of the multi-layer MPPs, based on Dah-You Maa’s general theory, is constructed using COMSOL and validated by impedance tube tests. Through such comprehensive analysis, the correlation between sound absorption performance and geometric parameters can be elucidated, enabling the identification of the desired configuration for multi-layer MPPs.