Hydraulic Performance of an Embankment Weir with Rough Crest
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VIEW THE REPLYPublication: Journal of Hydraulic Engineering
Volume 143, Issue 3
Abstract
An experimental study was conducted on a large embankment weir with smooth and rough crests for a range of flow conditions . Close agreement between the rough and smooth crest experiments was observed in terms of flow patterns, free-surface profiles, and pressure distributions. The crest roughness had effects on the velocity distributions, the boundary layer properties, and the shear stress. On the rough crest, the velocity distributions were shifted upwards, increasing the growth rate of the boundary layer. The calculation of the shear stresses with the law of the wall, outer flow region, and momentum integral methods showed consistent results of about for the smooth crest and of for the rough crest. The crest roughness reduced the discharge performance, while upstream and downstream ramps did not have any effects. The present observations highlighted the relevance of roughness and scaling on the hydraulic performances of weirs.
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Acknowledgments
The authors thank Martin Fong (UNSW Australia) for the collection of some of the experimental data. They thank Larry Paice and Rob Jenkins (WRL, UNSW Australia) for their technical assistance.
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©2016 American Society of Civil Engineers.
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Received: May 23, 2016
Accepted: Aug 5, 2016
Published online: Oct 10, 2016
Published in print: Mar 1, 2017
Discussion open until: Mar 10, 2017
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