Optimization of a Microperforated Panel backed by a Panel Resonator with Multi-resonators using Particle Swarm Optimization

A micro-perforated panel (MPP) is perceived as the next generation of sound absorbers which has an outstanding absorbing performance in the mid to high frequency range. However, MPPs often suffer from narrow absorption bandwidth and poor sound absorption in the low frequency range below 500Hz. Therefore, an MPP is backed by a panel-type resonator with installed multiple resonators (MPR), forming an MPP-MPR composite structure is proposed, which is able to improve the sound absorption performance in the low frequency region. The present study is aimed to optimize the resonators' resonant frequencies to further improve the low frequency absorption performance. A coupled vibroacoustic model is presented and particle swarm optimization (PSO) is employed to optimize the sound absorption performance. It is found that the optimization of all four resonators converged to four different resonant frequencies, improving absorption valleys. The optimization algorithm has demonstrated its ability to optimize the resonant frequencies of the resonators in improving the low frequency absorption, while also extending the half-absorption bandwidth.