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

error

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 3, 2009, 13:33
Default error
  #1
New Member
 
svdingare
Join Date: Oct 2009
Posts: 4
Rep Power: 7
svdingare is on a distinguished road
Pl let me know why we get following error?
Error: divergence detected in AMG solver: temperature
Error Object: ()
B.R.Sunil
svdingare is offline   Reply With Quote

Old   October 5, 2009, 09:52
Default
  #2
New Member
 
Join Date: Jun 2009
Posts: 8
Rep Power: 8
Bak_Flow is on a distinguished road
Dear Sunil,

this looks like a fluent error!

What the code is telling you is that at the non-linear (or outer iteration) you are on the Algebraic MultiGrid diverged. This means that you gave it a matrix that it could not reduce the residuals on.

There are only 2 ways to solve these problems:

1. Give it an easier (or reasonable) problem to solve
2. Work harder at solving it

It is useful in fluent to look at the behavior before this happend....what were the temperature residulas doing? What did the solution look like?

In approach 1 above what you can usually do is decrease the under-relaxations, drop to a first order method, solve a simpler problem...maybe you have made density a complicated function of temp, make a better mesh, make the initial guess closer to a solution, relax the problem by marching it as a transient to steady state, etc.

If you are close to have a problem you can solve then you can work on 2.....this is usually the case when you have something that is basically working but diverges occasionally......so just to get it throught the "tough spots" you give the AMG some tweaks....maybe a few more sweeps or a tighter tollerance, etc.

I hope this is of help.....please let us know how you make out.

Regards,

Bak_Flow
Bak_Flow is offline   Reply With Quote

Old   October 5, 2009, 10:04
Default
  #3
New Member
 
svdingare
Join Date: Oct 2009
Posts: 4
Rep Power: 7
svdingare is on a distinguished road
Dear bak_flow,
Thank you very much.
b.r.
sunil
svdingare 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
Compile problem ivanyao OpenFOAM Running, Solving & CFD 1 October 12, 2012 09:31
Problem with compile the setParabolicInlet ivanyao OpenFOAM Running, Solving & CFD 6 September 5, 2008 20:50
Compiling problems with hello worldC fw407 OpenFOAM Installation 21 January 6, 2008 18:38
DecomposePar links against liblamso0 with OpenMPI jens_klostermann OpenFOAM Bugs 11 June 28, 2007 17:51
user subroutine error CFDUSER CFX 2 December 9, 2006 07:31


All times are GMT -4. The time now is 20:42.