| Author: | Li, Sijie |
| Title: | Noise barriers with non-uniform edge impedance |
| Advisors: | Tang, S. K. (BSE) |
| Degree: | M.Eng. |
| Year: | 2015 |
| Subject: | Noise barriers -- Design and construction. Noise control. Transportation noise. Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Building Services Engineering |
| Pages: | 70 pages : color illustrations |
| Language: | English |
| Abstract: | In recent decades, with the development of transportation and expressway, the noise generated from the traffic becomes more and more seriously. To control and reduce the noise are the popular topics in recent acoustics study. The noise reduction of noise barrier is mainly used insertion loss to evaluate and this dissertation uses the model experiment method to test the insertion loss. The model experiment method will return to the original condition in the outside environment. Noise barriers have different kinds of structures, this article is mainly concerned with the performance and comparison of some different kinds of edges. All edges are in the same condition with same materials, same height and same experiment environment. And next, we used the MATLAB and EXCEL to calculate and analysis how the structure of the edges influences the performance. Finally, to point out which kind of edge will perform better than others in which range of frequency. The results show that the uniform edges which manufactured by MPP method with perforation ratio of 0.43% performs well in the range of 1900-2000hz and 2300-2700hz with the ΔIL of 2dB more than normal barrier. And the non-uniform edge and the non-uniform edge with different impedance, which these two have the perforation ratio of 0.44%, perform well in the range of 150-250hz with the ΔIL of 1.5dB more than normal barrier. And all edges perform similar to other with a distance of 90cm to the central of the barrier. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b28261471.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.45 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- 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.
- 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.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/8236