Oblique incidence sound absorption of parallel arrangement of multiple micro-perforated panel absorbers in a periodic pattern

Absorption of oblique incidence sound by a finite micro-perforated panel absorber.

In this paper, a theoretical model of a micro-perforated panel (MPP) backed by a finite cavity and flush-mounted in an infinite baffle is developed and its performance in terms of sound absorption is analyzed. The model allows an oblique incidence sound impinging upon the MPP absorber. The simplified Rayleigh integral method, thin plate theory and the acoustical impedance of the MPP are used to...

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...

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...

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...