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

Divergence error

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 12, 2014, 07:36
Default Divergence error
  #1
New Member
 
Akash
Join Date: Jun 2014
Location: Aachen
Posts: 16
Rep Power: 3
pakanatiakash is on a distinguished road
hullo

I am new to AVL Fire and I am trying to simulate melting phenomena using the porosity technique available. The case I am taking up is a simple Stefan problem of one dimension. Once I start the iteration I am getting this error, say after 6 iterations -

Problem diverges : Continuity equation, variable: Pressure correction

I tried to change the under relaxation factors and also employed stable schemes but its of no use. The pressure correction is also on.

Could somebody give insight into whats causing this problem. I am using 2011.1 version. Thank you

Akash
pakanatiakash is offline   Reply With Quote

Old   June 13, 2014, 02:29
Default
  #2
New Member
 
Changdeo
Join Date: Jan 2013
Location: Pune, India
Posts: 13
Rep Power: 4
chang.gaikwad is on a distinguished road
I don't have the experience with the type of problem you are solving. But you might check if you have right pressure initialization. Use the average pressure value that you expect in the CFD domain for initialization. Using zero value of velocity and density sometimes help to give stable start to the problem.
chang.gaikwad is offline   Reply With Quote

Old   June 18, 2014, 06:01
Default
  #3
New Member
 
Akash
Join Date: Jun 2014
Location: Aachen
Posts: 16
Rep Power: 3
pakanatiakash is on a distinguished road
Thanks for the suggestion. I found the solution but its kind of weird. I ran the simulation in 2013.1 version and it had this problem. I later ran it in 2013.2 version with the same setup and it works just fine. I am assuming there was some bug which was fixed in the later versions. Maybe more specifically in the melting simulation module. But I would like to know if the reason is different from what i thought.
pakanatiakash is offline   Reply With Quote

Old   June 18, 2014, 06:06
Default
  #4
New Member
 
Changdeo
Join Date: Jan 2013
Location: Pune, India
Posts: 13
Rep Power: 4
chang.gaikwad is on a distinguished road
I have more weird experience with v2010.1. Sometimes when simulation (transient) diverge just restarting it with last saved BC files will converge it.

Its good to know v2013.2 is doing better job that v2013.1. I am planning to start using v2013.2 soon. Thanks for the feedback.
chang.gaikwad 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
blockMesh with double grading. spwater OpenFOAM Native Meshers: blockMesh 78 March 12, 2015 15:54
Compile calcMassFlowC aurore OpenFOAM Programming & Development 12 March 18, 2014 05:22
compile error in dynamicMesh and thermophysicalModels libraries NickG OpenFOAM Installation 2 August 30, 2013 07:42
Compile problem ivanyao OpenFOAM Running, Solving & CFD 1 October 12, 2012 09:31
How to get the max value of the whole field waynezw0618 OpenFOAM Running, Solving & CFD 4 June 17, 2008 05:07


All times are GMT -4. The time now is 16:09.