Broadband sound absorption based on impedance decoupling and modulation mechanisms

Zhongjian Mei, Xiaodong Li, Yadong Lyu*, Jinqiu Sang, Xiaobin Cheng, Jun Yang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)

Abstract

In sound absorbers, acoustic resistance and reactance are usually coupled together and affect each other, which brings difficulties to impedance matching. An impedance decoupling method is proposed to make acoustic resistance and acoustic reactance vary independently. For the same thickness and perforation rate, acoustic reactance of the perforated panel with tube bundles (PPTBs) varies with the diameter of the tube, but acoustic resistance remains constant. Theoretical and simulated results show that a PPTB absorptive unit can exhibit resonance modes with varying damping states through impedance decoupling. It is found that through well-modulation, the PPTB unit in a slightly over-damped state cannot only maintain high sound absorption coefficients, but also expand the absorption peak bandwidth. Utilizing the mechanism of impedance decoupling, a broadband absorber is designed and evaluated by comprising the PPTB and microperforated panel (MPP). Measurement results indicate that it possesses an average absorption coefficient of 85% spanning more than a 3-octave bandwidth from 160 Hz to 1400 Hz with a deep sub-wavelength thickness. The impedance decoupling method helps to implement sound absorbers with highly efficient low-frequency broadband absorption.

Original languageEnglish
Pages (from-to)3479-3486
Number of pages8
JournalJournal of the Acoustical Society of America
Volume154
Issue number5
DOIs
Publication statusPublished - Nov 1 2023
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2023 Acoustical Society of America.

ASJC Scopus Subject Areas

  • Arts and Humanities (miscellaneous)
  • Acoustics and Ultrasonics

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