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

Sensitivity Analysis - Grids Not Asymptotic

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 10, 2009, 12:52
Default Sensitivity Analysis - Grids Not Asymptotic
  #1
Marc
Guest
 
Posts: n/a
Before running my simulations I'm trying to validate my grids by performing a sensitivity analysis to ensure I'm converging to a grid independent solution.

However, although I've generated 6 grids ranging from very coarse to extremely dense, all meeting the boundary layer conditions of my turbulence model, I'm finding that my results are not asymptotically converging. That is, each grid had results that consistently differ by 8-9%.

I have never run into this situation before and would like any ideas as to how I can solve this problem.

Thanks!
  Reply With Quote

Old   January 10, 2009, 21:51
Default Re: Sensitivity Analysis - Grids Not Asymptotic
  #2
zongtwi
Guest
 
Posts: n/a
Try using grid adaption in FLUENT and see what sort of grid you will get.

Hope that helps.
  Reply With Quote

Old   November 8, 2017, 07:35
Default Mesh independency problem
  #3
New Member
 
Sibel
Join Date: Apr 2017
Posts: 18
Rep Power: 5
tsibel is on a distinguished road
Hi everyone
I have a problem. You can see from the picture that I tried different mesh sizes. But tendency of the lines are different. This is steady state solution and SST(automatic wall function).

Does somebody has an idea?

Thanks!
Attached Images
File Type: png Untitled2.png (77.3 KB, 7 views)
tsibel is offline   Reply With Quote

Reply

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
Optimization Sensitivity rohtav OpenFOAM 1 June 16, 2010 08:46
sensitivity analysis Silvia FLUENT 1 November 3, 2005 05:48
Asymptotic (invariance) assumption in turbulence vasanth Main CFD Forum 0 October 24, 2004 12:14
Asymptotic Theory of Separated Flows Mike Main CFD Forum 2 July 20, 2004 12:08
Sensitivity and uncertainty of CFD Jim Main CFD Forum 4 March 9, 2004 20:01


All times are GMT -4. The time now is 06:27.