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

Divergence problem for species transport model

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 14, 2008, 01:33
Default Divergence problem for species transport model
  #1
MY
Guest
 
Posts: n/a
Hello all,

I'm solving a species transport model with wall surface reaction on parallel FLUENT. The surface reaction UDF is compiled fine and UDF library is loaded, but when calculation starts I get the following error:

divergence detected in AMG solver: species-0

divergence detected in AMG solver: species-0

divergence detected in AMG solver: species-0

divergence detected in AMG solver: species-0

divergence detected in AMG solver: species-0

divergence detected in AMG solver: species-0

Primitive Error at Node 0: floating point exception

Primitive Error at Node 1: floating point exception

Primitive Error at Node 3: floating point exception

Primitive Error at Node 4: floating point exception

Primitive Error at Node 2: floating point exception

Primitive Error at Node 5: floating point exception

Error: floating point exception

Error Object: #f

after about three iterations. The UDF defines a wall surface reaction rate for laminar finite-rate model and does not involve any calculation that requires sending or receiving data from another compute node (or the host) and therefore the code is not parallelised.

Can anyone guide me as to what might be the cause of this error?

Many thanks in advance
  Reply With Quote

Old   April 7, 2012, 09:01
Default How to set boundary conditions
  #2
New Member
 
Join Date: Apr 2012
Posts: 1
Rep Power: 0
Soulstealer is on a distinguished road
Hi,
I am a beginner in fluent and find it difficult to set up boundary conditions.
Can someone please help how to setup boundary conditions.I am given two options 1.interior-solid 2.wall-solid.
My project is to estimate the energy losses in an open channel bend.
Thank You for your response
Soulstealer is offline   Reply With Quote

Old   July 10, 2012, 09:18
Default
  #3
New Member
 
Jeff
Join Date: Jul 2012
Posts: 1
Rep Power: 0
Bigunclejethro is on a distinguished road
Hi MY - from what I've read the floating point error occurs as a result of an impossible mathematical operation (ex - dividing by zero). I have yet to find out exactly how this happens but possible solutions include reducing your timestep (transient flow), reducing the courant number (coupled solver). These have worked for some people but have not worked for me. Maybe you will have better luck.

Soulstealer - you need to define the boundary names before going into fluent. This can be done in the Ansys Mesher by clicking on the face, right click and select named selection. Once this is done, FLUENT will show these boundaries in the Boundary Conditions panel and allow you to set them up
Bigunclejethro is offline   Reply With Quote

Old   January 11, 2014, 05:46
Default Species with boundary condition
  #4
New Member
 
Pramod Raj
Join Date: Jan 2014
Posts: 2
Rep Power: 0
tppraj is on a distinguished road
Hai friends,
I am new in fluent. I don't know how the species is introduced in the fluent for the nozzle flow. I am using the density based implicit solver with structured mesh. so please help me to introduce the species in the fluent.
Thanking you
tppraj 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
Fixed Bed Gasifier, Species Transport Problem therandomestname FLUENT 11 May 8, 2011 09:20
Problem with turbulence model akonduri OpenFOAM 2 September 17, 2010 00:49
Is it possible to use divergence in the source term of an scalar transport equation? jannnesss CFX 0 January 8, 2010 20:53
lenght and number of nodes for an orifice meter flow problem - k-eps model fofo FLUENT 0 November 15, 2009 04:49
Converge problem of Mixture Model Jen FLUENT 8 August 17, 2005 18:23


All times are GMT -4. The time now is 07:27.