<abstract xmlns="http://www.w3.org/1999/xhtml"><p>In this work the performance of Reynolds Averaged Navier-Stokes (RANS) simulations to predict the flow structure developed by the presence of a sidewall obstacle in a uniform open-channel shallow flow is discussed. The tested geometry was selected due to its important role in several fluvial applications, such as the control of riverbank erosion and the creation of improved ecological conditions in river restoration applications. The results are compared against experimental laboratory velocity fields obtained after Large Scale Particle Image Velocimetry (LSPIV) measurements. It is shown that the length of reattachment of the separated shear layer generated by the obstacle is well predicted by a Reynolds Stress Model, while classical two-equation models show important limitations. All the performed RANS simulations are unable to properly predict the formation of a secondary gyre region, which develops immediately downstream the obstacle.</p></abstract>

In this work the performance of Reynolds Averaged Navier-Stokes (RANS) simulations to predict the flow structure developed by the presence of a sidewall obstacle in a uniform open-channel shallow flow is discussed. The tested geometry was selected due to its important role in several fluvial applications, such as the control of riverbank erosion and the creation of improved ecological conditions in river restoration applications. The results are compared against experimental laboratory velocity fields obtained after Large Scale Particle Image Velocimetry (LSPIV) measurements. It is shown that the length of reattachment of the separated shear layer generated by the obstacle is well predicted by a Reynolds Stress Model, while classical two-equation models show important limitations. All the performed RANS simulations are unable to properly predict the formation of a secondary gyre region, which develops immediately downstream the obstacle.

Assessment of 3D-RANS models for the simulation of topographically forced shallow flows

Department of Civil Engineering, University of Mohaghegh Ardabili, Daneshgah Street, 56199-11367, Ardabil, Iran.

Structural and Civil Engineering Department, University of Sheffield, Sir Frederick Mappin Building, Mappin Street, Sheffield, S1 3JD, UK.

Journal of Hydrology and Hydromechanics

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

In this work the performance of Reynolds Averaged Navier-Stokes (RANS) simulations to predict the flow structure developed by the presence of a sidewall...

Assessment of 3D-RANS models for the simulation of topographically forced shallow flows

Published Online: Jan 26, 2016

Page range: 83 - 90

Received: Dec 17, 2014

Accepted: Nov 11, 2015

DOI: https://doi.org/10.1515/johh-2016-0008

Keywords
Shallow flow, RANS, SPIV, Side obstacle, Shear layer, Turbulence

© 2016 Akbar Safarzadeh et al., published by De Gruyter Open

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

Assessment of 3D-RANS models for the simulation of topographically forced shallow flows

Published Online: Jan 26, 2016

Page range: 83 - 90

Received: Dec 17, 2014

Accepted: Nov 11, 2015

DOI: https://doi.org/10.1515/johh-2016-0008

KeywordsShallow flow, RANS, SPIV, Side obstacle, Shear layer, Turbulence

© 2016 Akbar Safarzadeh et al., published by De Gruyter Open

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

Keywords
Shallow flow, RANS, SPIV, Side obstacle, Shear layer, Turbulence