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

Time Evolution of TKE (LES)

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 21, 2011, 18:37
Default Time Evolution of TKE (LES)
  #1
Member
 
Join Date: Jul 2010
Posts: 52
Rep Power: 16
MaryBau is on a distinguished road
Hi All;

I am simulating decaying turbulence using a case very similar to the tutorial channelFoam/channel395. The only difference is that I have cyclic boundaries in all directions, so no walls.

I want to plot the time evolution of the averaged turbulence kinetic energy, but I am not sure how.

1. Are there any utilities already coded in OF to do this easily?

2. If not, how can I modify postChannel to get the TKE per time step for the whole domain, and not per region?

I tried modifying the function collapse() in channelIndexTemplate.C to returned the summedField instead of the regionField, but got wierd results.

Thanks, I appreciate your help!!

Mary
MaryBau is offline   Reply With Quote

Old   March 22, 2011, 08:40
Default
  #2
New Member
 
Ozgur Kirlangic
Join Date: May 2009
Location: Istanbul
Posts: 16
Rep Power: 17
ozgur is on a distinguished road
Hi,

If you are returning summedField instead of regionField you are still getting discrete values for different regions on the vertical line.

The only difference is that instead of getting the average values, you are getting the cumulative values of the fields, which are summed over discrete cell values. Therefore the values are still on region basis and also the cell value summation doesnot represent true integratation over those planes !

So, by an alternative loop maybe in an alternative function you may calculate and return the value of the overall field value integration which needs to be done by an algorithm like trapezoidal or simpson etc.


Özgür

Last edited by ozgur; March 29, 2011 at 08:39.
ozgur is offline   Reply With Quote

Reply

Tags
channelfoam, les model, post-processing, time averaged


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
Time Step in LES salehi144 ANSYS 2 October 21, 2010 18:32
caracteristic turbulence time in LES skippy FLUENT 0 September 16, 2004 11:51
Displaying LES Time Averaged Statistics Ben FLUENT 1 May 12, 2004 07:18
Komogrov time scale and implicit scheme for LES Li Yang Main CFD Forum 1 January 17, 2004 02:13
unsteady calcs in FLUENT Sanjay Padhiar Main CFD Forum 1 March 31, 1999 13:32


All times are GMT -4. The time now is 04:07.