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

Residual fluctuation patterns

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 17, 2014, 08:14
Post Residual fluctuation patterns
  #1
New Member
 
Nick Prendergast
Join Date: Dec 2013
Posts: 27
Rep Power: 3
neprendo is on a distinguished road
Hey everyone.

I'm modelling a 2d aerofoil in air and I had convergence (~2500 iterations) when using a courser mesh so I refined the mesh to check for mesh independence. Now however the residuals seem to fluctuating in a pattern and the solution is not converging by 10000 iterations. Can anyone tell me how this could be happening and what I can do to fix it?

Thanks
Nick
Attached Images
File Type: jpg fluctuating residuals.jpg (59.5 KB, 12 views)
neprendo is offline   Reply With Quote

Old   June 19, 2014, 04:03
Default
  #2
New Member
 
Nick Prendergast
Join Date: Dec 2013
Posts: 27
Rep Power: 3
neprendo is on a distinguished road
I have since found out this numerical noise with both high and low frequency oscillations and solved the problem by turning on the SA turbulence model.

Nick
neprendo is offline   Reply With Quote

Reply

Tags
residuals fluent

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
simpleFoam error - "Floating point exception" mbcx4jc2 OpenFOAM Running, Solving & CFD 10 April 21, 2015 19:45
Unstabil Simulation with chtMultiRegionFoam mbay101 OpenFOAM Running, Solving & CFD 13 December 28, 2013 14:12
pimpleFoam: turbulence->correct(); is not executed when using residualControl hfs OpenFOAM Running, Solving & CFD 3 October 29, 2013 09:35
calculation stops after few time steps sivakumar OpenFOAM Running, Solving & CFD 7 March 17, 2013 07:37
Orifice Plate with a fully developed flow - Problems with convergence jonmec OpenFOAM Running, Solving & CFD 3 July 28, 2011 05:24


All times are GMT -4. The time now is 09:13.