Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
A DES Study for the Role of Contraction Ratio on the Coherent Structures Caused by Two Spill Through Abutments
Date
2013-09-13
Author
Köken, Mete
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
157
views
0
downloads
Cite This
Detached Eddy Simulation (DES) is used to investigate the changes in the horseshoe vortex system and the bed shear stress distribution forming around the base of spill-through bridge abutments located at two sides of the channel for two different contraction ratios. DES is conducted at a channel Reynolds number of 45,000, and the incoming flow was fully turbulent that contains resolved turbulence fluctuations. Simulations are conducted at flat bed conditions representing the initiation of the scour process. The horseshoe vortex system is the main mechanism responsible for the local scour around the abutments and once the contraction ratio is increased some changes in the structure of the horseshoe vortex is observed. Moreover, a pair of coherent vortices, which were not present in the low contraction ratio, form in the middle of the channel oriented in the streamwise direction. These changes result in a large difference in the magnitude and pattern of the shear stress and pressure fluctuation distributions on the bed and hence thought to have a huge impact on the sediment entrainment and scour mechanism at the initial stages of scour.
Subject Keywords
Turbulent flow
,
Spill through abutment
,
Horseshoe vortex system
,
Detached Eddy Simulation
URI
https://hdl.handle.net/11511/54012
Collections
Department of Civil Engineering, Conference / Seminar
Suggestions
OpenMETU
Core
A Large Eddy Simulation study of the bed shear stress distributions around isolated and multiple groynes
Constantinescu, G.; Köken, Mete; McCoy, A. (2008-12-01)
Large Eddy Simulation is used to investigate the main coherent structures playing a role in the erosion process (e.g., horseshoe vortex system forming around the base of the groynes, eddies shed in the separated shear layer) and the associated bed shear stress distributions around isolated and multiple groynes placed in straight channels. For isolated groynes we investigate the flow at conditions corresponding to the start of the scouring process (flat bed) and to its end (equilibrium scour bathymetry). Als...
Effect of spur dike length on the horseshoe vortex system and the bed shear stress distribution
Köken, Mete; Göğüş, Mustafa (2015-03-04)
Turbulent flow structures forming around isolated spur dikes in a horizontal channel are investigated in this study. In the analysis detached eddy simulation is used under fully turbulent incoming flow conditions at a channel Reynolds number of 45,000. Changes in the structure of the horseshoe vortex system, bed shear stress and pressure standard deviation on the bed are investigated for three different spur dike lengths. In all of the cases the main horseshoe vortex undergoes bimodal oscillations, which le...
An investigation of coherent structures in the wake of a bridge abutment at equilibrium bed scour conditions
Köken, Mete (2007-01-01)
The database from a Large Eddy Simulation (LES) calculation is used to investigate the dominant coherent structures in the wake of a vertical bridge abutment in a straight channel with deformed bed corresponding to equilibrium scour bathymetry. The bathymetry is obtained from an experiment conducted at the same Reynolds number. The incoming flow is fully turbulent in both experiment and simulation. Dye visualizations are used to validate the numerical predictions. It is observed the directions at which the ...
Coherent structures in a sharply curved bend with and without a spur dike.
Köken, Mete; Budak, Ezgi (null; 2017-08-18)
: Results of three-dimensional (3D) Detached Eddy Simulation (DES) are used to investigate the changes in flow and large-scale coherent structures within a high-curvature open channel, with and without an isolated spur dike located on the outer bank of the
Investigation of flow around a bridge abutment in a flat bed channel using Large Eddy Simulation
Köken, Mete (2007-12-01)
Large Eddy Simulation (LES) is used to numerically investigate the horseshoe vortex (HV) system around a vertical bridge abutment located on a flat bed in a straight channel with vertical lateral walls corresponding to conditions at the initiation of the scour process. The simulation is performed with upstream fully turbulent flow including the turbulent fluctuations obtained from a precalculated LES simulation. The dynamics of the instantaneous coherent structures associated with the HV system around the b...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
M. Köken, “A DES Study for the Role of Contraction Ratio on the Coherent Structures Caused by Two Spill Through Abutments,” 2013, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54012.
