Multi-objective Design Optimization for Compact and Broadband Double Layer Microperforated Panel Sound Absorber

Abstract

Microperforated panel absorbers (MPP) are acoustic absorbers that consist of a perforated panel fitted in front of a rigid wall and air cavity. The absorption frequency range of MPP is limited in the vicinity of the resonance frequencies due to the sound absorption mechanism. The sound absorption frequency band of MPP can be expanded by adding resonance structures such as parallel arrangement and multilayer arrangement, and optimal design of structural parameters. Unfortunately, the approaches increase the volume of the whole absorber. It is important to minimize the volume of the absorber for compactness while widening the absorption frequency range. In this paper, multi-objective optimization of the MPP for widening the bandwidth of the sound absorption and minimizing the volume is performed. The normal sound absorption coefficient of double layer MPP is evaluated by the transfer matrix method, and sequential approximate optimization using radial basis function network is adopted to identify the trade-off relationship between the broadband sound absorption and the volume. Based on the numerical result, the experiment is also carried out to examine the validity of the proposed approach.