Full metadata record
DC FieldValueLanguage
Department:Department of Building Services Engineeringen_US
Author:Li, Wai-manen_US
Title:The performance of coupled resonators in the presence of turbulent flowsen_US
Abstract:Helmholtz resonators are used to attenuate the unwanted sound in a variety of applications. This dissertation presents the findings on coupled resonators in the presence of turbulent flows. The sound attenuation of coupled resonators installed along a rectangular duct was studied experimentally at five air flow velocities: 0 m/s, 3 m/s, 5 m/s, 7 m/s, 9 m/s. Experiments demonstrate that the coupled resonators are tested under high turbulence intensities. Experiments confirm that the transmission loss of the coupled resonators generally drops with a higher velocity. The coupled resonators can perform effective sound attenuation for an air flow below 9 m/s. Negative troughs occur at the resonance frequency when the air flow velocity exceeds a certain value. The resonance frequencies of the resonators remain unchanged in the air flow conditions. The experimental results reveal that there is interaction between coupled resonators under different air flows. And the attenuation frequency bandwidth is widened by tuning the neck width of the resonators close to each other under both no flow and flow conditions.en_US
Pages:xii, 122, 12 leaves : ill. (some col.) ; 30 cmen_US
Degree:All Masteren_US
Subject:Hong Kong Polytechnic University -- Dissertationsen_US
Subject:Turbulence -- Acoustic propertiesen_US
Subject:Air ducts -- Acoustic propertiesen_US
Access:restricted access-

Files in This Item:
File Description SizeFormat 
b18100211.pdfFor All Users (off-campus access for PolyU Staff & Students only)13.8 MBAdobe PDFView/Open

Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show simple item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/4473