To enhance sound absorption of Helmholtz resonance metamaterials in low frequency region with simple structure and engineering practicability, according to the well-established acoustic absorption theory of micro-perforated panel, a novel designed Helmholtz resonance metamaterial with extended microperforated neck is proposed, and a theoretical modelling method is developed by using the transfer matrix method which is validated by finite element simulation. Both theoretical calculation and finite element simulation results show that sound absorption performance of proposed Helmholtz resonance metamaterial is improved significantly compared to that of Helmholtz resonator with normal neck, and the resonant absorption coefficient is close to 1. The influence of geometric parameters of microperforated neck is also investigated in detail, and some meaningful conclusions are drawn. This work provides a perfect solution for low-frequency noise control with Helmholtz resonance metamaterials.
Du et al. (Wed,) studied this question.