Minimum Specific Energy and Critical Flow Conditions in Open Channels
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VIEW THE REPLYPublication: Journal of Irrigation and Drainage Engineering
Volume 132, Issue 5
Abstract
In open channels, the relationship between the specific energy and the flow depth exhibits a minimum, and the corresponding flow conditions are called critical flow conditions. Herein they are reanalyzed on the basis of the depth-averaged Bernoulli equation. At critical flow, there is only one possible flow depth, and a new analytical expression of that characteristic depth is developed for ideal-fluid flow situations with nonhydrostatic pressure distribution and nonuniform velocity distribution. The results are applied to relevant critical flow conditions: e.g., at the crest of a spillway. The finding may be applied to predict more accurately the discharge on weir and spillway crests.
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Acknowledgments
The writer thanks Dr. Sergio Montes (The University of Tasmania) for many helpful exchanges and discussion. He thanks further Professor A. S. Ramamurthy (Concordia University, Canada) for providing the original data of his former Ph.D. student (Vo 1992) and Professor C. J. Apelt (The University of Queensland) for helpful comments.
References
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© 2006 ASCE.
History
Received: Jun 2, 2005
Accepted: Dec 9, 2005
Published online: Oct 1, 2006
Published in print: Oct 2006
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