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

AMG solver divergent

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 28, 2016, 02:31
Default AMG solver divergent
  #1
New Member
 
Reza Rahnama
Join Date: Apr 2016
Posts: 2
Rep Power: 0
rezarahnama is on a distinguished road
Hi everybody
i am working on a case that models sterlization of a fermentor with steam.modeling consitions and setups are listed below:
Density based
Transient and multiphae (wetsteam)
Boundary Conditions are pressure inlet= 2 bar, 233 C and pressure outlet=1.6 bar, 129 C
I used inviscid flow
soloution method is implicit
when i start to calculate and run the case after about 5-15 iteration, solution diverge and i face to listed errors :
# Divergence detected in AMG solver: > Increasing relaxation sweeps!
# Divergence detected in AMG solver: Coupled -> Decreasing coarsening group size!
Divergence detected in AMG solver: WSB-eq
Divergence detected in AMG solver: WSN-eq


can anybody help me to resole this problem?
rezarahnama is offline   Reply With Quote

Old   April 29, 2016, 17:08
Default
  #2
Senior Member
 
Lucky Tran
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 1,372
Rep Power: 20
LuckyTran will become famous soon enough
What does inviscid multiphase flow of wet steam even look like?

Anyway, since you are running a transient case and it diverged in 15 or so iterations, does that mean that it diverged on the very 1st iteration?

Most likely, you have incorrect initial conditions or your mesh is really bad. I would check those first. Make sure your initial conditions for all variables are consistent. For transient simulations you often need to generate the initial conditions from another simulation.

Also check your mesh quality. Run the mesh check and see if there are any glaring issues.
LuckyTran is offline   Reply With Quote

Reply

Tags
amg solver, divergent, wsb-eq

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
Divergence detected in AMG solver: temperature R4RAHUL FLUENT 6 September 16, 2014 17:44
Fluent IcePak - AMG Solver Russ FLUENT 1 December 25, 2013 09:26
Working directory via command line Luiz CFX 4 March 6, 2011 21:02
reverse flow and divergence in AMG solver MASOUD FLUENT 2 April 2, 2010 08:48
AMG versus ICCG msrinath80 OpenFOAM Running, Solving & CFD 2 November 7, 2006 16:15


All times are GMT -4. The time now is 01:02.