Coherent structures in a sharply curved bend with and without a spur dike.

: 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


Flow structure and large scale turbulence in an open channel bend of strong curvature with flat and deformed bed
Constantinescu, G.; Köken, Mete (2014-09-05)
Results of Three-Dimensional (3D) Detached Eddy Simulation (DES) are used to discuss changes in flow structure and large-scale turbulence structures in a high-curvature open channel between conditions present at the start (flat bed) and at the end (equilibrium deformed bed) of the erosion-deposition process. The flow in a 193 degrees bend is simulated, for which the ratio between the bend curvature and the channel width is close to 1.3. For these geometrical parameters, the cross-stream secondary flow and a...
Coherent structures at different contraction ratios caused by two spill-through abutments
Köken, Mete (Informa UK Limited, 2017-8-23)
Detached eddy simulation (DES) at a channel Reynolds number of 45,000 is used to investigate the coherent structures forming around spill-through abutments located at opposite sides of a rectangular channel which contract the flow section. Changes in the coherent structures are investigated for two contraction ratios at two different scour stages. It is observed that at the small contraction ratio the coherent structures forming around the abutments are similar to the ones observed for isolated abutments. H...
Coherent structures around isolated spur dikes at various approach flow angles
Köken, Mete (2011-01-01)
The turbulent flow structures around an isolated spur dike located at three different approach flow angles are investigated. Detached eddy simulation is used at a channel Reynolds number of 45,000. Experimental velocity measurements were also conducted using acoustic Doppler velocimetry for validating the simulations. It is found that the size and orientation of the horseshoe vortex system change considerably with the approach flow angle. The main necklace vortex is largest in size and most coherent for 90 ...
Yalçın, Özgür; Özyörük, Yusuf; Department of Aerospace Engineering (2021-11-1)
This dissertation investigates the boundary layer transition as well as the cavity flow noise prediction capabilities of a high-order in-house solver using various Delayed Detached-Eddy Simulation (DDES) frameworks. Before conducting the simulations, multiblock topology with a high-order overset grid technique is implemented into the solver, which makes mesh generation for complex geometries, such as the tunnel grids around blade sections, and cavity grids composed of two separate domains of the studied cas...
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...
Citation Formats
M. Köken and E. Budak, “Coherent structures in a sharply curved bend with and without a spur dike.,” 2017, Accessed: 00, 2021. [Online]. Available: