<abstract xmlns="http://www.w3.org/1999/xhtml"><p>In an open-channel, the transition of a flow from a subcritical to a supercritical state may occur as a result of a lateral inflow or outflow that produces a streamwise discharge variation. Apparently, such a transition cannot be modeled accurately by a conventional hydrostatic pressure approach. In this study, a depth-averaged model that accounts for the effects of a spatially-varied discharge and a non-hydrostatic pressure distribution was developed and applied to simulate the transcritical flow in a lateral-spillway channel and the subcritical flow in a main channel fitted with side weirs. The model results for the axial free-surface profile and variation of discharge in the main channel were compared with the results of a shallow-flow model and experimental data, thereby resulting in a closer match to the measurements than the shallow-flow model. Overall, the investigation results confirmed the efficiency and validity of the non-hydrostatic depth-averaged model in simulating the mean flow characteristics of the subcritical and transcritical free-surface flows with spatially increasing or decreasing discharges, thus demonstrating its potential to be used as a numerical tool in engineering practice.</p></abstract>

In an open-channel, the transition of a flow from a subcritical to a supercritical state may occur as a result of a lateral inflow or outflow that produces a streamwise discharge variation. Apparently, such a transition cannot be modeled accurately by a conventional hydrostatic pressure approach. In this study, a depth-averaged model that accounts for the effects of a spatially-varied discharge and a non-hydrostatic pressure distribution was developed and applied to simulate the transcritical flow in a lateral-spillway channel and the subcritical flow in a main channel fitted with side weirs. The model results for the axial free-surface profile and variation of discharge in the main channel were compared with the results of a shallow-flow model and experimental data, thereby resulting in a closer match to the measurements than the shallow-flow model. Overall, the investigation results confirmed the efficiency and validity of the non-hydrostatic depth-averaged model in simulating the mean flow characteristics of the subcritical and transcritical free-surface flows with spatially increasing or decreasing discharges, thus demonstrating its potential to be used as a numerical tool in engineering practice.

On Steady Two-dimensional Free-surface Flows with Spatially-varied Discharges

David & James – Engineering and Environmental Consultancy

Slovak Journal of Civil Engineering

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"On Steady Two-dimensional Free-surface Flows with Spatially-varied Discharges"}

In an open-channel, the transition of a flow from a subcritical to a supercritical state may occur as a result of a lateral inflow or outflow that produces a...

On Steady Two-dimensional Free-surface Flows with Spatially-varied Discharges

Published Online: Oct 04, 2019

Page range: 1 - 11

DOI: https://doi.org/10.2478/sjce-2019-0016

Keywords
Hydraulicstructures, Side-weir overflow, Non-hydrostatic flow, Spatially-varied flow, Numerical model, Side-channel spillway

© 2019 Yebegaeshet T. Zerihun, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

On Steady Two-dimensional Free-surface Flows with Spatially-varied Discharges

Published Online: Oct 04, 2019

Page range: 1 - 11

DOI: https://doi.org/10.2478/sjce-2019-0016

KeywordsHydraulicstructures, Side-weir overflow, Non-hydrostatic flow, Spatially-varied flow, Numerical model, Side-channel spillway

© 2019 Yebegaeshet T. Zerihun, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Hydraulicstructures, Side-weir overflow, Non-hydrostatic flow, Spatially-varied flow, Numerical model, Side-channel spillway