Aeration, Flow Instabilities, and Residual Energy on Pooled Stepped Spillways of Embankment Dams
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VIEW THE REPLYPublication: Journal of Irrigation and Drainage Engineering
Volume 139, Issue 10
Abstract
Air-water flow experiments were conducted on some flat and pooled stepped spillways with slopes of 8.9° and 26.6° in transition and skimming flows. The study comprised the observations of the flow patterns, characteristic air-water flow properties, and energy dissipation performances. The air-water flow properties showed some differences in terms of interfacial velocity, bubble count rate, and turbulence intensity between the stepped chutes for the two channel slopes. These differences were also reflected in the residual energy data, highlighting a better energy dissipation rate for the pooled stepped spillway with slope of 8.9°. However, the aerated flows on the pooled stepped spillways exhibited some hydrodynamic instabilities, and a safe operation must be tested in physical models. The flat stepped spillway appeared to be the preferable design in terms of energy dissipation and flow stability.
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Acknowledgments
The authors thank Professor Holger Schüttrumpf (IWW, RWTH Aachen University) for providing access to the experimental facility and Jason Van Der Gevel and Stewart Matthews (The University of Queensland) for their technical assistance. The financial supports through a UQ research scholarship and through the Australian Research Council (Grant DP120100481) are acknowledged.
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© 2013 American Society of Civil Engineers.
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Received: Dec 6, 2012
Accepted: Apr 17, 2013
Published online: Apr 19, 2013
Discussion open until: Sep 19, 2013
Published in print: Oct 1, 2013
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