The presence of vegetation in open channel flow has a significant influence on
flow resistance, turbulence structures and sediment transport. This study will
evaluate flow resistance and scale velocity profile in depth limited flow conditions,
specifically investigating the impact of vegetation on the flow resistance under
submerged flow conditions. The resistance induced by vegetation in open
channel flows has been interpreted differently in literature, largely due to different
definitions of friction factors or drag coefficients and the different Reynolds
numbers. The methods utilized in this study are based on analytical and
numerical models to investigate the effects of vegetation presence on flow
resistance in open channel flows. The performing strategy approach was
applied by three-dimensional computational fluid dynamics (CFD)
simulations, using artificial cylinders for the velocity profile. This is to estimate
the average flow velocity and resistance coefficients for flexible vegetation, which
results in more accurate flow rate predictions, particularly for the case of low Reynolds number. This thesis shows different formulas from previous studies
under certain conditions for a length scale metric, which normalises velocity
profiles of depth limited open channel flows with submerged vegetation, using
both calculated and simulated model work. It considers the submerged
vegetation case in shallow flows, when the flow depth remains no greater than
twice the vegetation height. The proposed scaling has been compared and
developed upon work that have been influenced by logarithmic and power laws
to present velocity profiles, in order to illustrate the variety of flow and vegetation
configurations.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/19049 |
| Date | January 2020 |
| Creators | Hussain, Awesar A. |
| Contributors | Pu, Jaan H., Guo, Yakun |
| Publisher | University of Bradford, Faculty of Engineering and Informatics |
| 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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