Air Entrained in Flow along a Steep-Stepped Spillway: Data and Insights from a Hydraulic Model
Publication: Journal of Hydraulic Engineering
Volume 147, Issue 5
Abstract
Data and insights are presented on air entrainment in a hydraulic model of the stepped spillway for Gross Dam, Colorado, soon to be the tallest stepped spillway in the United States. The spillway’s chute was steep (2.0V:1.0H) and curved, and converged about 20% from its top to its base width. Data show that streamwise values of air concentration and flow depth were practically constant near the chute’s end for the spillway’s design discharge. The chute’s planform curvature resulted in nonuniform flow depth across the chute; flow depth along the chute’s centerline was greater than flow depth at the sidewall but contained slightly less entrained air. At the end of the chute, the average air concentration (volumetric proportion of bulked flow) varied from about 0.55–0.61. The depth-averaged concentration of entrained air near the end of the chute decreased with increasing water discharge, and was less than the equilibrium value suggested by the literature. The chute’s converging sidewalls caused slight increases in flow depth and reductions in flow velocity near the sidewalls.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request. The data include air concentrations, flow velocities, and bulked depths of flow.
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Information
Published In
Journal of Hydraulic Engineering
Volume 147 • Issue 5 • May 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Jul 8, 2020
Accepted: Nov 25, 2020
Published online: Mar 4, 2021
Published in print: May 1, 2021
Discussion open until: Aug 4, 2021
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