RIGID-LID LES PREDICTIONS OF THE 3D-FLOW IN AN OPEN-CHANNEL CONFLUENCE WITH CONCORDANT AND DISCORDANT BEDS

2019 ◽  
Author(s):  
PEDRO XAVIER RAMOS ◽  
LAURENT SCHINDFESSEL ◽  
JOÃO PEDRO PÊGO ◽  
TOM DE MULDER
Keyword(s):  
Open Channel ◽  
3D Flow ◽  
Channel Confluence

scholarly journals Turbulent flow structure at a 90-degree open channel confluence: Accounting for the distortion of the shear layer

2016 ◽  
Vol 12 ◽  
pp. 130-147 ◽  
Author(s):  
Saiyu Yuan ◽  
Hongwu Tang ◽  
Yang Xiao ◽  
Xuehan Qiu ◽  
Huiming Zhang ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Shear Layer ◽  
Flow Structure ◽  
Open Channel ◽  
Turbulent Flow Structure ◽  
Channel Confluence

Flow patterns in an open channel confluence with a small ratio of main channel to tributary discharge

2014 ◽  
pp. 989-996 ◽  
Author(s):  
L Schindfessel ◽  
S Creëlle ◽  
T Boelens ◽  
T De Mulder
Keyword(s):  
Open Channel ◽  
Flow Patterns ◽  
Main Channel ◽  
Small Ratio ◽  
Channel Confluence

scholarly journals Flat vs. curved rigid-lid LES computations of an open-channel confluence

2019 ◽  
Vol 21 (2) ◽  
pp. 318-334 ◽  
Author(s):  
Pedro Xavier Ramos ◽  
Laurent Schindfessel ◽  
João Pedro Pêgo ◽  
Tom De Mulder
Keyword(s):  
Free Surface ◽  
Secondary Flow ◽  
Open Channel ◽  
Pressure Field ◽  
Large Eddy Simulations ◽  
Numerical Treatment ◽  
Mean Flow ◽  
Large Eddy ◽  
Flow Case ◽  
Channel Confluence

Abstract This paper describes the application of four Large Eddy Simulations (LES) to an open-channel confluence flow, making use of a frictionless rigid-lid to treat the free-surface. Three simulations are conducted with a flat rigid-lid, at different elevations. A fourth simulation is carried out with a curved rigid-lid which is a closer approximation to the real free-surface of the flow. The curved rigid-lid is obtained from the time-averaged pressure field on the flat rigid-lid from one of the initial three simulations. The aim is to investigate the limitations of the free-surface treatment by means of a rigid-lid in the simulation of an asymmetric confluence, showing the differences that both approaches produce in terms of mean flow, secondary flow and turbulence. After validation with experimental data, the predictions are used to understand the differences between adopting a flat and a curved rigid-lid onto the confluence hydrodynamics. For the present flow case, although it was characterized by a moderately low downstream Froude number (Fr ≈ 0.37), it was found that an oversimplification of the numerical treatment of the free-surface leads to a decreased accuracy of the predictions of the secondary flow and turbulent kinetic energy.

Experimental Investigation of Free Surface Gradients in a 90° Angled Asymmetrical Open Channel Confluence

2018 ◽  
pp. 803-819 ◽  
Author(s):  
Stéphan Creëlle ◽  
Lukas Engelen ◽  
Laurent Schindfessel ◽  
Pedro X. Ramos ◽  
Tom De Mulder
Keyword(s):  
Experimental Investigation ◽  
Free Surface ◽  
Open Channel ◽  
Channel Confluence

Three-dimensional flow structure at fixed 70° open-channel confluence with bed discordance

2019 ◽  
Vol 58 (3) ◽  
pp. 434-446 ◽  
Author(s):  
Olga Birjukova Canelas ◽  
Rui M.L. Ferreira ◽  
Sebastián Guillén-Ludeña ◽  
Francisco C. Alegria ◽  
António H. Cardoso
Keyword(s):  
Flow Structure ◽  
Open Channel ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Channel Confluence

scholarly journals ANALYSIS OF OPEN-CHANNEL CONFLUENCE FLOW HAVING DIFFERENT STEEP SLOPES IN FIXED BED AND MOVABLE BED

2007 ◽  
Vol 51 ◽  
pp. 823-828
Author(s):  
Takashi DEGUCHI ◽  
Ichiro FUJITA ◽  
Ryota TSUBAKI ◽  
Masashi OZONO
Keyword(s):  
Open Channel ◽  
Fixed Bed ◽  
Steep Slopes ◽  
Movable Bed ◽  
Channel Confluence

scholarly journals Numerical Investigation of Vertical Crossflow Jets with Various Orifice Shapes Discharged in Rectangular Open Channel

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1505
Author(s):  
Hao Yuan ◽  
Ruichang Hu ◽  
Xiaoming Xu ◽  
Liang Chen ◽  
Yongqin Peng ◽  
...  
Keyword(s):  
Open Channel ◽  
Velocity Ratio ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Turbulent Model ◽  
3D Flow ◽  
Turbulent Characteristics ◽  
Square Jets ◽  
Flow Turbulence ◽  
Vertical Jet

Vertical jet in flowing water is a common phenomenon in daily life. To study the flow and turbulent characteristics of different jet orifice shapes and under different velocity ratios, the realizable k-ε turbulent model was adopted to analyze the three-dimensional (3D) flow, turbulence, and vortex characteristics using circular, square, and rectangular jet orifices and velocity ratios of 2, 5, 10, and 15. The following conclusions were drawn: The flow trajectory of the vertical jet in the channel exhibits remarkable 3D characteristics, and the jet orifice and velocity ratio have a significant influence on the flow characteristics of the channel. The heights at which the spiral deflection and maximum turbulent kinetic energy (TKE) occur for the circular jet are the smallest, while those for square jets are the largest. As the shape of the jet orifice changes from a circle to a square and then to a rectangle, the shape formed by the plane of the kidney vortices and the region above it gradually changes from a circle to a pentagon. With the increase in the velocity ratio, the 3D characteristics, maximum TKE, and kidney vortex coverage of the flow all gradually increase.

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