Control of sound transmission in a duct using Helmholtz resonators

Pao Yue-kong Library Electronic Theses Database

Control of sound transmission in a duct using Helmholtz resonators

 

Author: Wang, Denghui
Title: Control of sound transmission in a duct using Helmholtz resonators
Degree: M.Eng.
Year: 2016
Subject: Resonators.
Noise control.
Hong Kong Polytechnic University -- Dissertations
Department: Dept. of Building Services Engineering
Pages: 5, 54 pages : color illustrations
Language: English
InnoPac Record: http://library.polyu.edu.hk/record=b2917145
URI: http://theses.lib.polyu.edu.hk/handle/200/8624
Abstract: Helmholtz resonator or HR for short, can be used as a passive noise control method to improve the transmission loss of the duct and pipe inside the ventilation and air conditioning system. A single Helmholtz resonator can produce an obviously sound wave attenuation in a narrow band around its resonance frequency, but the theory and the experimental frequency range has deviation. Various kinds of corrections have been proposed for different size of Helmholtz resonator, therefore it is necessary to determine an accurate correction for the size of the building ventilation pipe. It has also been revealed that a single HR has a narrow attenuation range, thus it is a common method to combine resonators in an array to expand the frequency range of reducing noise. According to the former research, the resonance frequency and transmission loss are governed by the physical dimensions of duct, neck and cavity. By using both Mathematical and transfer matrix method to analyze the acoustic performance of Helmholtz resonator, the project believe that it is necessary to reveal the relationship between the size of resonator and duct with the transmission loss, select a more accurate correction for the duct-HR system, and then provide an operable solution to improve its performance, therefore Helmholtz resonator can be widely used for building noise control.

Files in this item

Files Size Format
b29171453.pdf 1.615Mb PDF
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.

     

Quick Search

Browse

More Information