Application of Fawer Theory to End Depth in Trapezoidal Sloping Channel
Publication: Journal of Irrigation and Drainage Engineering
Volume 145, Issue 12
Abstract
The Fawer assumption is applied to both energy and momentum equations to analyze free overfalls for a trapezoidal sloping channel in the supercritical flow regime under the assumption of pseudouniform flow. This model mainly focuses on the effect of streamline curvature on supercritical free overfalls. Available experimental data are used to calibrate the Fawer exponent ; it was found that is a good approximation for trapezoidal supercritical free overfall. A comparison shows that the Fawer assumption will lead to more accurate discharge and end-depth ratio () estimates than the weir theory or the conventional Boussinesq assumption whether it is used in the energy or momentum approach. The Fawer-type momentum approach predicted discharge with an error and was closest to the observed discharges, whereas the Boussinesq-type energy approach predicted discharge with an error up to 20% and was farthest away from the observed discharges. Both graphical and explicit solutions for supercritical flow discharge using known channel characteristics and end depth are also provided.
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Acknowledgments
This work was supported by the National Natural Science Foundation of China (Grant No. 51739011) and the National Key Research and Development Plan (2016YFC0402707-03).
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Journal of Irrigation and Drainage Engineering
Volume 145 • Issue 12 • December 2019
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©2019 American Society of Civil Engineers.
History
Received: Apr 25, 2019
Accepted: Aug 6, 2019
Published online: Sep 28, 2019
Published in print: Dec 1, 2019
Discussion open until: Feb 28, 2020
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