Hydraulic losses in sewer pipes are caused by wall roughness, blockages and
in-pipe sedimentation. Hydraulic resistance is a key parameter that is used to
account for the hydraulic energy losses and predict the sewer system
propensity to flood. Unfortunately, there are no objective methods to measure
the hydraulic resistance in live sewers. A common method to estimate the
hydraulic resistance of a sewer is to analyse collected CCTV images and then
to compare them against a number of suggested hydraulic roughness values
published in the Sewer Rehabilitation Manual.
This thesis reports on the development of a novel, non-invasive acoustic
method and instrumentation to measure the hydraulic roughness in partially
filled pipes under various structural and operational conditions objectively. This
research presents systematic laboratory and field studies of the hydraulic and
surface water wave characteristics, of shallow water flows in a sewer pipes with
the presence of local and distributed roughness, in order to relate them to some
fundamental properties of the acoustic field measured in the vicinity of the flow
surface. The results of this thesis indicate that for the local roughness the
energy content of the reflected acoustic signal is an indicator of the pipe head
loss and hydraulic roughness. In the case of the distributed roughness, the
variation in the temporal and frequency characteristics of the propagated sound
wave can be related empirically to the mean flow depth, mean velocity, wave
standard deviation and hydraulic roughness.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/6321 |
| Date | January 2013 |
| Creators | Romanova, Anna |
| Contributors | Horoshenkov, Kirill V., Tait, Simon J. |
| Publisher | University of Bradford, School of Engineering, Design and Technology |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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