Low-frequency broadband absorbers based on coupling micro-perforated panel and space-curling chamber

Sound attenuation using duct silencers with micro-perforated panel absorbers

Micro-perforated panel (MPP) can be used as non-fibrous acoustic absorber which can provide broadband sound absorption performance. In this study, a sub-structuring methodology based on the Patch Transfer Function (PTF) approach to deal with duct silencers with MPP absorbers and internal partitions is proposed, and the sound attenuation performance of such silencers is investigated. Reactive si...

Vibroacoustics of thin micro-perforated sound absorbers

Calculation of absorption coefficient of micro-perforated absorbers

Micro-perforated absorber is a newly developed sound absorber, and it has a number of attractive features: • Unlike conventional perforated absorbers, micro-perforated absorber can be made from transparent materials like plastic glass. • Unlike commonly used fibrous absorptive materials, micro-perforated absorber is fibrous-free and thus, there is no health concern. • Micro-perforated membranes...

On the acoustic properties of parallel arrangement of multiple micro-perforated panel absorbers with different cavity depths.

The acoustic properties of a compound micro-perforated panel (MPP) absorber array are investigated. The absorber array consists of three parallel-arranged MPP absorbers with different cavity depths. A finite element procedure is used to simulate its acoustic behaviors under normal incidence. Experimental studies are carried out to verify the numerical simulations. Due to different reactance mat...

Low-Frequency Model for Radio-Frequency Absorbers

A simple model is developed to characterize the behavior of radio-frequency absorbers at low frequency. The absorber is represented by a flat, homogeneous, isotropic slab of lossy material, with effective constitutive parameters. These parameters are determined by a fit to measured data. Excellent fits are obtained in the two applications considered. The model is intended for use in the charact...