Analysis of Sound Absorption Materials with Double-Spiral Acoustic Resonators

  • 周 立志

Student thesis: Doctoral Thesis

Abstract

In recent years with the rapid development of industry people have been paying more and more attention to noise control In addition to making people feel uncomfortable high-decibel noise causes permanent hearing damage Low-frequency noise (< 500 Hz) is difficult to absorb with traditional porous sound-absorbing materials such as foam and fibers Therefore in this study we design an alternative absorbing structure for alleviating low-frequency sound The goal is to achieve total absorption at low frequency broaden absorption bandwidth and manipulate sound absorption band In this thesis Double-spiral resonator (DSR) is proposed By using the acoustic impedance theory the structural geometry is designed for attaining that the maximum sound absorption in the frequency range of interest With the finite element simulation software COMSOL Multiphysics the theoretical absorption coefficient of the models is verified and the acoustic pressure field particle velocity field and energy loss mechanism in the resonant cavity are examined Finally three-dimensional printing technology is used to fabricate test specimens and the impedance tube system is employed to measure the sound absorption coefficient under the ISO-10534-2 standard Theoretical results show that the DSR can achieve total sound absorption at 309 Hz and create an absorption bandwidth of 20 Hz (sound absorption coefficient > 0 5) and a thickness-to-wavelength ratio is about 1 08% In addition to the single-layer structure the further designs of the Two-layer resonators are also proposed
Date of Award2020
Original languageEnglish
SupervisorJung-San Chen (Supervisor)

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