Broadband quasi-perfect sound absorption by a metasurface with coupled resonators at both low- and high-amplitude excitations

Renhao Qu, Jingwen Guo, Yi Fang, Siyang Zhong, Xin Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

16 Citations (Scopus)

Abstract

This study presents an acoustic metasurface (AM) consisting of coupled Helmholtz resonators with extended necks (HRENs) to effectively absorb broadband sound waves at both low and high amplitudes. A nonlinear acoustic model is proposed to characterize the AM performance based on the equivalent medium theory and the transfer matrix method. The nonlinear effects due to the high-amplitude excitation are considered by a velocity-dependence equivalent density of the air in the neck. The acoustic characteristics of an AM with two coupled HREN units at the sound pressure level (SPL) ranging from 100dB to 140dB are analytically, numerically, and experimentally investigated. Results from the three approaches show good agreement. The AM achieves quasi-perfect absorption (absorption coefficient α>0.9) in a wide range of SPL, while each HREN unit alone only performs well at around 130dB. The superior absorption performance of the AM at relatively low-amplitude excitation originates from the coherent coupling effects between adjacent units. With the increase of the sound level, the coupling effects tend to deteriorate; fortunately, the sound-vortex conversions occur, contributing to additional acoustic dissipation and thereby sustaining the quasi-perfect absorption capability. Based on the absorption mechanisms, a broadband AM with multiple coupled resonators is designed and manufactured. The measured averaged absorption coefficient of the AM is larger than 0.91 at the SPL below 140 dB (α>0.97 at 100dB) within [700,1100]Hz, and the compact thickness is of 1/18 wavelength at the lowest operating frequency. The findings in this study offer a promising approach to achieve highly efficient broadband sound absorption in a wide-ranging noise level, which holds great potentials in practical applications for noise control.

Original languageEnglish
Article number110782
JournalMechanical Systems and Signal Processing
Volume204
DOIs
Publication statusPublished - 1 Dec 2023

Keywords

  • Acoustic metasurface with coupled resonators
  • Broadband sound absorption
  • High-amplitude sound excitation
  • Nonlinear effects

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Signal Processing
  • Civil and Structural Engineering
  • Aerospace Engineering
  • Mechanical Engineering
  • Computer Science Applications

Fingerprint

Dive into the research topics of 'Broadband quasi-perfect sound absorption by a metasurface with coupled resonators at both low- and high-amplitude excitations'. Together they form a unique fingerprint.

Cite this