CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Pre-Processing

Taylor Couette Setup and Boundary Conditions

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   August 22, 2013, 06:53
Default Taylor Couette Setup and Boundary Conditions
  #1
New Member
 
Danesh S
Join Date: Jul 2013
Location: Bochum, Germany
Posts: 27
Rep Power: 4
DaSh is on a distinguished road
Hello Fellow-FOAMers,

I am currently working on a setup for LES of a Taylor Couette flow. To test my setup and mesh, I start out with a laminar simulation (turbulence properties set to laminar).

I want to create both laminar couette flow and laminar taylor vortex flow. I use a setup with eta = 0.5, so I have a critical Reynoldsnumber of about 78.

The problem is, that I can see vortices on both ends of the cylinder for Reynolds = 50 (smaller than Re_crit) by visualising the y-compinents of velocitiy, like this:



Of course for laminar couette flow, there should be no velocities in y-direction.

I use icoFoam as laminar solver. Boundary conditions for p are all zeroGradient for innerWall outerWall and upper and lower end. For U all are fixedValue ( 0 0 0 ), just innerWall is

rotatingWallVelocity
origing (0 0 0)
axis (0 1 0)
omega 0.004; (rad/s, which leads to 0.002 m/s and Re = 50; viscosity 2e-5)


Has anybody got an idea how to improve the setup, or why i get these vortices at low Re? Maybe cyclic BC at top and bottom are necessary?

I am grateful for any kind of help!

Regards,
DaSh
DaSh is offline   Reply With Quote

Old   August 22, 2013, 06:55
Default
  #2
New Member
 
Danesh S
Join Date: Jul 2013
Location: Bochum, Germany
Posts: 27
Rep Power: 4
DaSh is on a distinguished road
I have tried cyclic BC and symmetryPlane BC, which produces even worse results concerning velocity in y-direction.

Has somebody got an idea, why I see y-Velocity (v) in laminar case with Re smaller Re_crit?

Thanks in advance!

Danesh
DaSh is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Symmetry and Periodic boundary conditions CFD_Fluent_User FLUENT 1 October 16, 2014 02:18
An error has occurred in cfx5solve: volo87 CFX 5 June 14, 2013 17:44
FLUENT changes my boundary conditions setup (2D transonic compressor airfoil) the_knife FLUENT 8 May 27, 2012 19:37
how to setup pressure boundary conditions? bioman6666 STAR-CCM+ 4 April 1, 2011 19:09
periodic boundary conditions setup studentcfd CFX 4 October 25, 2007 01:38


All times are GMT -4. The time now is 03:50.