CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Initial data for perturbU

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

Like Tree1Likes
  • 1 Post By cedric_duprat

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 24, 2009, 05:56
Default Initial data for perturbU
  #1
Member
 
Leonardo Giampani Morita
Join Date: Apr 2009
Location: Paris, France
Posts: 58
Rep Power: 17
leonardo.morita is on a distinguished road
Hello,

I'm going to work with LES and was told to start studying the cyclic channel case. I ran the tutorial and now I'm interested on testing the perturbU utility. However, I didn't find any information about the entries that are needed, other than the Retau in the transportProperties, so I'd like to know if somebody could explain how I can control the perturbations and how the files U, p etc( in the 0 folder) must be initialized (with arbitrary conditions?).

Thank you,

Leo
leonardo.morita is offline   Reply With Quote

Old   April 24, 2009, 07:45
Default
  #2
Senior Member
 
Cedric DUPRAT
Join Date: Mar 2009
Location: Nantes, France
Posts: 195
Rep Power: 17
cedric_duprat is on a distinguished road
Hi Leo,

The point is that you don't need other information. And, because Retau is used to define the amplitude of the noise, you can choose it arbitrary.

Check on the LES thread for reference paper of this tool (Schoppa and Hussain Fluid Dynamics Research 2001). Eugene de Villier Ph'd is still really good to get information for LES with OpenFOAM.

Then, you can have a look at the implementation, you don't need to be a C++ expert to get it. The main idea is to add a decreasing sinusoidal random noise to a parabolique profile for the velocity.

I hope It will help.

Cedric.

PS: for more information about LES channel flow, you can have a look there http://openfoamwiki.net/index.php/Si...ion_test_cases
and maybe add some usefull information for the community.
songwukong likes this.
cedric_duprat is offline   Reply With Quote

Old   April 24, 2009, 08:28
Default
  #3
Member
 
Leonardo Giampani Morita
Join Date: Apr 2009
Location: Paris, France
Posts: 58
Rep Power: 17
leonardo.morita is on a distinguished road
Thank you Cedric,

But should I have something (U, p etc) in the 0 folder before running perturbU? Or these files will be created by the application?

Leo

Last edited by leonardo.morita; April 24, 2009 at 08:52.
leonardo.morita is offline   Reply With Quote

Old   April 24, 2009, 08:55
Default
  #4
Member
 
Leonardo Giampani Morita
Join Date: Apr 2009
Location: Paris, France
Posts: 58
Rep Power: 17
leonardo.morita is on a distinguished road
Forget it...I realized that what I need to do is just to have an U file there, with an arbitrary profile (for example, a zero-velocity field)...
leonardo.morita is offline   Reply With Quote

Reply

Tags
channel, perturbu

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 07:20
How to write k and epsilon before the abnormal end xiuying OpenFOAM Running, Solving & CFD 8 August 27, 2013 16:33
Computational time sunnysun OpenFOAM Running, Solving & CFD 5 March 16, 2009 04:32
Differences between serial and parallel runs carsten OpenFOAM Bugs 11 September 12, 2008 12:16
Unknown error sivakumar OpenFOAM Pre-Processing 9 September 9, 2008 13:53


All times are GMT -4. The time now is 08:18.