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dc.contributorDepartment of Mechanical Engineeringen_US
dc.creatorXia, Jiajun-
dc.identifier.urihttps://theses.lib.polyu.edu.hk/handle/200/12433-
dc.languageEnglishen_US
dc.publisherHong Kong Polytechnic Universityen_US
dc.rightsAll rights reserveden_US
dc.titleA new type of sonic black hole device for sound absorptionen_US
dcterms.abstractNoise control has always been a serious concern in many fields, such as automotive and aviation industries. Existing noise control approaches, like using mufflers or traditional sound absorption materials, are not efficient for low frequency noise control. Despite the great efforts made by many researchers, the problem has still not been solved. The recent emergence of acoustic metamaterials shows new possibilities for potentially solving this problem. More specifically, a so-called acoustic black hole (ABH) structure has been proposed for sound and vibration control due to its appealing features in achieving effective energy trapping and dissipation. So far, the research on ABH mainly concentrates on flexural wave manipulation in structures like beams or plates. However, its exploration for sound reduction and control, referred to as sonic black hole (SBH), is quite limited.en_US
dcterms.abstractIn this dissertation, we investigated a SBH structure lined with micro-perforated panels (MPPs) inside. The main target is that this new perforation-modulated SBH can maximize the SBH effects and achieve low frequency and broadband sound absorption. Meanwhile, it can be put into practical use with a simpler internal configuration.en_US
dcterms.abstractThe study will emphasis on exploring the physical phenomenon behind SBH as well as evaluating its sound absorption performance from both theoretical and experimental perspective. More specifically, transfer matrix method (TMM) is adopted here to build the theoretical model to analyze the parametric influence on SBH effects. Finite element simulation (FEM) is then carried out to calculate the sound absorption coefficient with experimental validation following behind. Meanwhile, experiment results also reveal the existence of the slow-wave effect. The proposed perforation-modulated SBH shows great potential to deliver good sound absorption performance.en_US
dcterms.extentvii, 74 pages : color illustrationsen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.issued2022en_US
dcterms.educationalLevelM.Sc.en_US
dcterms.educationalLevelAll Masteren_US
dcterms.LCSHAbsorption of sounden_US
dcterms.LCSHMetamaterialsen_US
dcterms.LCSHNoise controlen_US
dcterms.LCSHHong Kong Polytechnic University -- Dissertationsen_US
dcterms.accessRightsrestricted accessen_US

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Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/12433