Multi synergistic coupling design for broadband sound absorption based on compact porous composite embedded with massless membrane resonator

Aiming at the poor absorption of metaporous below the quarter-wavelength resonance frequency, a novel metaporous featuring with continuous high absorption within low-frequency range was proposed based on multi synergistic coupling effects. On account of abundant adjustable parameters and coupling effects with porous domain, massless membrane resonator absorber (MMRA) was firstly designed as inclusion and embedded in polyurethane foam to form a metaporous absorber (MPA). Then, a developed metaporous absorber (DMPA) was designed step by step to achieve broadband absorption. The predicted and experimental results both indicate that an average absorption coefficient of 90% within 400-1500 Hz can be achieved, with the sample thickness of only 60 mm. Both weak and strong synergistic coupling between the porous materials and MMRA are found to form multi-wideband quasi-perfect absorption peaks. Broadband and low-frequency characteristics, as well as the flexible adjustability, make our design well promising in practical noise control engineering.

Automated summary

This study proposes a novel metaporous absorber that achieves continuous high absorption within the low-frequency range. By coupling with porous materials and utilizing adjustable parameters, a massless membrane resonator absorber (MMRA) is designed and embedded in polyurethane foam to form a metaporous absorber (MPA). Experimental results show that an average absorption coefficient of 90% within 400-1500 Hz can be achieved in a sample with a thickness of only 60 mm.