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

residual oscillation

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 13, 2006, 12:36
Default residual oscillation
  #1
philippe
Guest
 
Posts: n/a
Hello, I am studying enclosed convection in small cavity and I want to evaluate the influence of gas pressure on thermal plume developped by a heated wire at the bottom of the cavity. Under 5 bar results fit well with experience, but for higher pressure, residual values of continuity start to oscillate. Perhaps somebody could help me ? Thank you. Philippe
  Reply With Quote

Old   March 13, 2006, 14:22
Default Re: residual oscillation
  #2
mAx
Guest
 
Posts: n/a
switch on unsteady solver
  Reply With Quote

Old   March 14, 2006, 04:04
Default Re: residual oscillation
  #3
philippe
Guest
 
Posts: n/a
Ok, but do I use small time step (and it will take a long time) or a large step ? Thank you. Philippe
  Reply With Quote

Old   March 14, 2006, 04:32
Default Re: residual oscillation
  #4
mAx
Guest
 
Posts: n/a
if you ust to large time step, it won't converge. you must compute by hand the time step you need. for instance t=(minimum cell size of your domain)/(maximum velocity you are guessing) I would use adaptive time stepping
  Reply With Quote

Old   March 14, 2006, 04:38
Default Re: residual oscillation
  #5
philippe
Guest
 
Posts: n/a
I am just trying adaptative time step, thank you very much for your answer. Philippe
  Reply With Quote

Old   March 14, 2006, 04:40
Default Re: residual oscillation
  #6
mAx
Guest
 
Posts: n/a
de rien
  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
transsonic nozzle with rhoSimpleFoam Unseen OpenFOAM Running, Solving & CFD 8 July 1, 2022 07:54
Extrusion with OpenFoam problem No. Iterations 0 Lord Kelvin OpenFOAM Running, Solving & CFD 8 March 28, 2016 12:08
How to write k and epsilon before the abnormal end xiuying OpenFOAM Running, Solving & CFD 8 August 27, 2013 16:33
Orifice Plate with a fully developed flow - Problems with convergence jonmec OpenFOAM Running, Solving & CFD 3 July 28, 2011 06:24
Differences between serial and parallel runs carsten OpenFOAM Bugs 11 September 12, 2008 12:16


All times are GMT -4. The time now is 09:44.