Velocities and Turbulent Stresses of Free-Surface Skimming Flows over Triangular Cavities
Publication: Journal of Hydraulic Engineering
Volume 149, Issue 6
Abstract
Velocity distributions in supercritical open-channel flows over stepped cavities have traditionally been described using a power-law approach or theoretical solutions of plane mixing layers. These approaches were found to be valid either above the step edges or above/within step cavities, but no generalized model is available. In this study, a four-layered velocity model is proposed, which combines different physical concepts, including the mixing layer, log-layer, wake function, and free-stream layer. This multilayer model was applied to previous experimental stepped chute data, providing novel opportunities to comparatively assess the relative contribution of individual physical effects on the velocity profile. Model parameters provided insights into flow hydrodynamics, comprising mixing layer length scales and shear velocities. Equations for Reynolds shear stresses within the different layers were formulated using an eddy viscosity concept, while normal stresses and turbulent kinetic energy compared well to semitheoretical open-channel flow equations.
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Data Availability Statement
All data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
The author thanks António Amador for sharing his dataset. Fruitful discussions with Daniel Valero, Gangfu Zhang, and Daniel Bung are acknowledged.
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Journal of Hydraulic Engineering
Volume 149 • Issue 6 • June 2023
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© 2023 American Society of Civil Engineers.
History
Received: Jan 12, 2022
Accepted: Jan 12, 2023
Published online: Mar 31, 2023
Published in print: Jun 1, 2023
Discussion open until: Aug 31, 2023
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