|
[Sponsors] |
June 13, 2015, 09:19 |
turbulent vortex street behind a cylinder
|
#1 |
New Member
Andreas
Join Date: Dec 2014
Posts: 16
Rep Power: 12 |
Hello guys,
there are many studies and experiments about flows around cylinders. I have a basic question about ANSYS CFX operations to simulate the vortex behind the cylinder in turbulent flows. My Question is: How does CFX simulate which of the two vertical vortex systems behind a cylinder collapse and detach first in a symmetric simulationroom? I read in books that in reality, the totality of little processes (e.g dust) leads to the detachment of a particular vortex, but you cant say, which one it will be. Does anyone knows the procedure in CFX to simulate this phenomenon in transient simulations? Thanks in advance, Flashi |
|
June 14, 2015, 07:49 |
|
#2 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,863
Rep Power: 144 |
As the simulation starts two vorticies will form behind the cylinder. They will be almost the same size and shape, but due to small variations one will be slightly dominant over the other. This variation will be tiny - but enough such that it gets amplified and then the dominant vortex pushes the other vortex out of the way. And then the vortex street starts up behind this.
The variation will be caused by a combination of meshing, numerical errors, convergence and the geometry not being completely straight. |
|
June 14, 2015, 08:27 |
|
#3 |
New Member
Andreas
Join Date: Dec 2014
Posts: 16
Rep Power: 12 |
Thanks Ghorrocks, thats what i wanted to know!
|
|
Tags |
cfx, cylinder, transient, vortex |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Problem with divergence | TDK | FLUENT | 13 | December 14, 2018 07:00 |
Particle deposition on circular cylinder in turbulent flow | Julian K. | CFX | 1 | October 3, 2011 18:51 |
Need advices for simulating vortex shedding of moving cylinder | quyetthang | CFX | 0 | October 1, 2011 06:39 |
karman vortex street with turbulence and heated walls | jango | OpenFOAM | 6 | July 28, 2011 16:29 |
cylinder and Kármán vortex street | sarav | STAR-CCM+ | 1 | July 6, 2010 12:49 |