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

Error #001100279 Floating point exception: Zero divide

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 30, 2013, 13:55
Default Error #001100279 Floating point exception: Zero divide
  #1
New Member
 
Seran Reschim
Join Date: Jun 2012
Posts: 7
Rep Power: 5
ch_ohm is on a distinguished road
Dear all,

Now I have simulated the warehouse size 20*20*30 meters. It is quite big. I need to simulate and monitor the air temp in the warehouse (10 h). I work with transient model with time step = 1 hour. But I face with error as above

Error #001100279
Floating point exception: Zero divide

The software is Ansys 14 CFX. CPU core i5 with RAM 6 gb

Please help .

Thank you
ch_ohm is offline   Reply With Quote

Old   April 30, 2013, 17:25
Default
  #2
Senior Member
 
Erik
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 486
Rep Power: 9
evcelica is on a distinguished road
What influenced you to choose a 1 hour time step? That's probably several orders of magnitude too big!
evcelica is offline   Reply With Quote

Old   April 30, 2013, 19:36
Default
  #3
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,824
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
FAQ: http://www.cfd-online.com/Wiki/Ansys...do_about_it.3F

But Erik is right - your time step is miles too big.
ghorrocks is offline   Reply With Quote

Old   May 1, 2013, 05:09
Default
  #4
Senior Member
 
RicochetJ's Avatar
 
Mr CFD
Join Date: Jun 2012
Location: Britain
Posts: 290
Rep Power: 6
RicochetJ is on a distinguished road
In your warehouse do you have buoyancy driven flow?

In the CFX manual it tells you how to estimate the time step.

If you're doing transient simulations you might want to consider adaptive time stepping. Set the maximum time step to something like 1hr and the minimum to something small like 1e-8s and try to converge within 5-10 loops.
RicochetJ is offline   Reply With Quote

Old   May 1, 2013, 07:01
Default
  #5
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,824
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Agreed, adaptive timestepping is the best choice - especially for beginners who have no idea of what timestep is really required. I would say that half the convergence problems we see on this forum are just from too large a timestep.

For most simulations 3-5 coeff loops is more appropriate. 5-10 is only required for models with tricky physics to converge suck as multiphase (but for most multphase models I still use 3-5).
ghorrocks is offline   Reply With Quote

Old   May 1, 2013, 07:49
Default
  #6
Senior Member
 
RicochetJ's Avatar
 
Mr CFD
Join Date: Jun 2012
Location: Britain
Posts: 290
Rep Power: 6
RicochetJ is on a distinguished road
Quote:
Originally Posted by ghorrocks View Post
Agreed, adaptive timestepping is the best choice - especially for beginners who have no idea of what timestep is really required. I would say that half the convergence problems we see on this forum are just from too large a timestep.

For most simulations 3-5 coeff loops is more appropriate. 5-10 is only required for models with tricky physics to converge suck as multiphase (but for most multphase models I still use 3-5).

Would you consider buoyancy driven flow to be "tricky".
RicochetJ is offline   Reply With Quote

Old   May 1, 2013, 08:05
Default
  #7
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,824
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
No. 'Tricky' means in this case where complex coupling between phases/physics is required; such as 2-way coupled particle tracking, eularian particle models, chemistry, radiation modelling where the fluid flow interacts 2-ways with the radiation modelling and things like that.

Buoyancy is still single phase so that is best done with short time steps converged quickly - so 3-5 coeff loops per iteration.
ghorrocks is offline   Reply With Quote

Old   May 4, 2013, 05:47
Default
  #8
New Member
 
Seran Reschim
Join Date: Jun 2012
Posts: 7
Rep Power: 5
ch_ohm is on a distinguished road
Thank you all. I will try follow your suggest. Thank you again.
ch_ohm 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
simpleFoam Floating point exception error -help sudhasran OpenFOAM Running, Solving & CFD 3 March 12, 2012 17:23
Pipe flow in settlingFoam floating point exception jochemvandenbosch OpenFOAM Running, Solving & CFD 4 February 16, 2012 04:24
block-structured mesh for t-junction Robert@cfd ANSYS Meshing & Geometry 20 November 11, 2011 05:59
Finished simulation doesn't start: floating point exception [Divide by zero] MaxCFD STAR-CCM+ 3 June 26, 2011 10:31
Floating point error: divide by zero Chris FLUENT 2 April 15, 2005 02:33


All times are GMT -4. The time now is 04:53.