Design and Optimization of 2-MMPPHR Based on Micro-Perforated Panels and Helmholtz Resonators

In recent years, the issue of low-frequency broadband sound absorption in noise control has attracted considerable attention in the field of research and engineering. In this paper, an innovative acoustic metamaterial structure, the second-order multi-layer Micro-perforated panel absorbers backed by Helmholtz resonators (2-MMPPHR), comprising multiple microperforated panel integrated with a Helmholtz resonator is proposed. Utilizing the local resonance principle of Helmholtz resonators and the characteristics of microperforated panel, we successfully achieve broadband sound absorption across low and medium to high frequency ranges. Through sensitivity analysis of structural parameters, we identify significant effects of Helmholtz resonator parameters on both the absorption coefficient and bandwidth. Lastly, employing genetic algorithm optimization, we attain a 2-MMPPHR configuration with 80% sound absorption within the region of 296-1000 Hz.