A comparative study of cavity resonance-based acoustic metamaterial components on absorption characteristic

Abstract Cavity resonance-based acoustic metamaterials (CRAM) offer promising prospects for low-frequency noise reduction. Helmholtz resonator absorbers (HRA), micro-perforated panels (MPP), and coiling-up space (CUS) are three representative CRAM components. This paper systematically evaluates primary acoustic impedance modeling methods for HRA, MPP, and CUS by comparing with simulation and experimental results, and identifies the most suitable approach. The peak absorption frequency of CRAM is governed by the modal frequency and corresponding mode shape. In HRA and MPP, thermoviscous losses arise mainly from the neck, with a minor contribution from the cavity, whereas in CUS, all channels contribute. The sensitivity to the incident angle decreases in the order of MPP, HRA, and CUS. The sensitivity to acoustic nonlinear effects of HRA, MPP, and CUS decreases successively. This paper could provide a holistic perspective for the sound absorption analysis of CRAM units, and offer valuable guidance for the design and applications of CRAM.