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

Error Object: nan

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 22, 2005, 18:59
Default Error Object: nan
  #1
Kajal Mehta
Guest
 
Posts: n/a
Hi all,

I get an error (plz see below) while solving a steady-state natural convection simulation.

Error: > (greater-than): invalid argument [2]: wrong type [not a number] Error Object: nan

Does this error look familiar to someone? Any guidance is much appreciated!

Thanks, Kajal Mehta
  Reply With Quote

Old   July 22, 2005, 23:06
Default Re: Error Object: nan
  #2
Saurav
Guest
 
Posts: n/a
Well ball park answer, ur mass momentum and energy eqns. are all diverging. As u haven't mentioned anything about what u r solving for, can't comment anything further...by the way one guess...under relax ur equations...might still get NAN but not as soon as u might be getting right now....

Saurav
  Reply With Quote

Old   July 23, 2005, 00:28
Default Re: Error Object: nan
  #3
Mahesh
Guest
 
Posts: n/a
Can u mention, what r u solving for?
  Reply With Quote

Old   July 23, 2005, 05:19
Default Re: Error Object: nan
  #4
Swarup
Guest
 
Posts: n/a
Check your input boxes. Although I am not sure about this, I think you have not written a number properly or you have mentioned something very much larger/smaller than allowed. the solver is ultimately ending up with 0/0 or inf/inf; hence the message. Swarup
  Reply With Quote

Old   August 1, 2005, 12:13
Default Re: Error Object: nan
  #5
Mohamed HENDAWI
Guest
 
Posts: n/a
Hi I receive the same error (see below plz) I'm modelizing a water droplet jet with evaporation (DPM model, unsteady solver, k e tubulence model ).

The computaion seemed converging correctly until about 6000 iteration (time =0.91 s with time step=0.01s) and 1262 of tracked particles (by injection of 20 per time step). Then I receive the same error!!!

Any idea? Thaks in Advance Mohamed

PS: error message (at the end):

Updating solution at time level N... done.

start time:0.000000e+00s, stop time: 1.000000e+01s, time:9.299999e-01s time step:9.999990e-03s

DPM Iteration .... Time of the Day : Hour =13 Min=0

start time:0.000000e+00s, stop time: 1.000000e+01s, time:9.299999e-01s time step:9.999990e-03s

start time:0.000000e+00s, stop time: 1.000000e+01s, time:9.299999e-01s time step:9.999990e-03s Injecting 20 particles at t = 0.93 number tracked = 1302, escaped = 0, aborted = 0, trapped = 0, evaporated = 16, incomplete = 0, coalesced = 0, shed = 7 Parallel particle tracking concurrency: 0%

iter continuity x-velocity y-velocity z-velocity energy k epsilon h2o vm_s vm_y time/iter

Error: > (greater-than): invalid argument [2]: wrong type [not a number] Error Object: nan
  Reply With Quote

Old   August 1, 2005, 12:49
Default Re: Error Object: nan
  #6
Swarup
Guest
 
Posts: n/a
Hi Mohammed, are you sure that none of the residuals is going out of control? Ultimate reason for such an error is an undefined quantity. This is happening after a lot of iterations. I guess errors in calculation of some quantity are building up slowly till that time and then there is blow-up. I am unable to pin-point the source and can give you some hints. You should check whether any region of your computational domain experiences lot of changes in a short time and how fine/appropriate your grid is in that region. To be sure, you may review all your inputs and boundary conditions. Please check with Fluent support team if problem is still persisting.

Best Of Luck.

Swarup.
  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
error in grmsch? Adam Beamish FLOW-3D 2 September 2, 2011 04:05
F-packing problem Streamlet FLOW-3D 4 April 29, 2011 03:41
Cells with t below lower limit Purushothama CD-adapco 2 May 31, 2010 21:58
Unfamiliar Error coops OpenFOAM Running, Solving & CFD 7 October 3, 2006 13:54
Could anybody help me see this error and give help liugx212 OpenFOAM Running, Solving & CFD 3 January 4, 2006 19:07


All times are GMT -4. The time now is 01:25.