Entropy Parameter Estimation in Large-Scale Roughness Open Channel
Publication: Journal of Hydrologic Engineering
Volume 20, Issue 2
Abstract
The entropy model allows estimating, in an expeditive way, both water discharge and flow velocity field in open channels. In fact, such a model presents an almost simple analytical structure based on the evaluation of a single parameter calculated through the ratio between the mean and maximum flow velocities in the cross section. Recent studies have demonstrated that for large-scale roughness, the evaluation of the entropy parameter seems to be affected by the local conditions near the bed. In order to investigate such influence, this paper proposes an explicit relationship between the entropy parameter and the relative submergence. This relation was validated using data collected in a rectangular tilting flume of laboratory in which the bed roughness was composed of elements of regular shape such as spheres. Several tests were performed in conditions of large-scale roughness () and for different values of slope () and water discharge (). The method shows a good agreement between the observed and calculated data for both the velocity profiles and water discharges.
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Acknowledgments
This work was partly funded by the PRIN Italian Project, 2008, “Entropic modelling for the evaluation of the hydrodynamic characteristic in free surface flows.”
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Information & Authors
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Published In
Journal of Hydrologic Engineering
Volume 20 • Issue 2 • February 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Jun 5, 2013
Accepted: Apr 7, 2014
Published online: Apr 10, 2014
Discussion open until: Jan 5, 2015
Published in print: Feb 1, 2015
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