Micro‐Perforated Panels – Assessing the Sound Absorption

Abstract

Nowadays micro‐perforated panels (MPP) are continuously gaining interest in terms of the efficient design, simulation and the acoustic energy absorption capacity. The MPP construction and functionality is based on the Helmholtz resonator. The present article presents and discusses a couple sets of MPPs made of plastic and wood of different design. The analyzed MPP samples have different geometrical parameters such as the microperforation diameter, the panel thickness and the distance between holes. The MPP structure is coupled with sound‐absorbing materials of different thicknesses which are partially or completely filling the air between the perforated plate and the backing rigid surface. A series of measurements performed by using the impedance tube, in order to determine the sound absorption coefficient are mentioned. The mathematical modeling approaches are presented with references to the Maa theory and experimental models like the one developed by Delany and Bazley. The coupling effort for design, mathematical modelling and experimental validation will ends into conclusions and preferred absorbing structure proposals for the highest sound absorption effciency and for the widest frequency band. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)