Numerical modelling and optimisation of reverberation cutback for packed spheres

Abstract

Against multiple sources of experimentally measured data, Attenborough’s acoustic porous media has proven to be a better predictor of the reverberation cutback for packed beds of near-spherical structures compared to several other equivalent fluid models. Numerical predictions using Attenborough’s model were therefore used to illuminate the importance of key pore-structure related parameters of packed structures on their normal incidence sound absorption spectra. A parametric study was instigated to account for the influence of void fraction and particle size on predicted broadband sound absorption properties targeting permeability values in the range of 0.3 to 2.0×10−09m2. This approach could assist material manufacturers and acoustic engineers in the design of highly efficient and timely packed structures for applications-specific to sound absorption.