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

Pls help imp!! Convergence of natural convection model

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

Reply
 
LinkBack Thread Tools Display Modes
Old   May 9, 2013, 15:25
Default Pls help imp!! Convergence of natural convection model
  #1
New Member
 
Laura
Join Date: Apr 2013
Posts: 15
Rep Power: 4
laura_c is on a distinguished road
Hi guys, I am modelling natural convection - laminar - steady state.

the model is a box with 2 inlets and 1 outlet and a heater inside.

the residuals are steady but high and it is not converging. i tried to lower the under relaxation values but still residuals are high. I read that natural convection usually converges in transient simulations and that it is frequent that does not converge in steady state.

is it wrong to keep this model and use it? will it give me wrong values?

pls help...my deadline is in a week and i m having strong doubts about this!!

thanks
laura_c is offline   Reply With Quote

Old   May 15, 2013, 04:47
Default
  #2
New Member
 
Rajesh Kumar
Join Date: Apr 2009
Posts: 23
Rep Power: 8
rajeshkunwar is on a distinguished road
Hi, Laura

Yes there are issues with steady state simulation of natural convection problem. You should have a good mesh and right boundary condition to get convergence. check your boundary conditions.
rajeshkunwar is offline   Reply With Quote

Old   May 15, 2013, 08:03
Default
  #3
Member
 
Join Date: Aug 2011
Posts: 54
Rep Power: 6
MachZero is on a distinguished road
I know one of my coworkers was having a similar problem and had to not only solve it in transient, but had to slowly increase gravity from 0 to 10
MachZero is offline   Reply With Quote

Reply

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
Superlinear speedup in OpenFOAM 13 msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 06:36
Is it possible to model natural convection in a 2D horizontal model in fluent caitoc FLUENT 1 May 5, 2014 13:32
laminar or turbulent model for natural convection ans281086 FLUENT 0 April 21, 2011 06:30
Natural Convection Problem - Helium marzoa STAR-CCM+ 0 April 18, 2011 14:12
Approximate Mixing due to Natural Convection Greg Perkins Main CFD Forum 0 February 12, 2003 19:43


All times are GMT -4. The time now is 02:33.