| Author: | Wang, Manli |
| Title: | Transient-based characterization and detection of different pipe defects in urban water supply pipelines |
| Advisors: | Duan, H. F. (CEE) |
| Degree: | M.Sc. |
| Year: | 2019 |
| Subject: | Pipeline failures Pipelines Underwater pipelines -- Maintenance and repair Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Civil and Environmental Engineering |
| Pages: | viii, 58 pages : color illustrations |
| Language: | English |
| Abstract: | The urban water distribution system is responsible for the daily water demand of citizens. Long-term burial underground may cause many different types of pipe defects (e.g. leaks, blockages, corrosion and air pockets) in the water distribution system, which are not likely to be detected in time. These defects affect the efficiency of the system and result in wasting a large amount of water and energy resources. However, the efficiency and accuracy of existing methods for detecting pipeline defects are not sufficient. In the past two decades, a new method based on transient pressure waves has been invented and applied to the detection of different pipeline defects. Although the transient-based method is efficient, non-destructive and economical, it can only be applied to relatively simple pipelines system conditions, such as pipe systems contain a single defect or multiple defects with known type. In practical applications, different types of defects may coexist in the pipeline system, and the current transient-based method is incapable of detecting them accurately. The aim of this thesis is to extend this transient-based method to characterize and detecting different types of pipe defects coexisting in the water pipeline. Two common types of pipeline defects, leaks, and discrete blockage are examined and system frequency response function is employed to study the transient response under the multiple defect conditions so as to further applied to detect defects in pipelines. More specifically, the frequency response functions of different defects configurations are first derived analytically by transfer matrix method in the frequency domain, and then the numerical results from the method of characteristics (MOC) are used to verify the analytical results before the results are further applied to detect the discrete blockage and leak in the system. The results show that the equation obtained by the transfer matrix of the pipeline system with defects can well describe the responses with different defects in the system, and the analytical results can be further utilized to detect and predict the defects in the pipeline. It is worth noting that the results of this study can provide substantial progress in the development and application of the transient based method. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 5295.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 1.55 MB | Adobe PDF | View/Open |
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