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

floating point error during grid adaptation

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 3, 2001, 01:18
Default floating point error during grid adaptation
  #1
Nurul Murad
Guest
 
Posts: n/a
hey guys..

i'm trying to refine my grid size by using the register...ie. adapting the grid by using pressure gradient, velcoty gradient, volume change and also boundary condition...

however, i get a floating point error during the adaptation. usually after getting the error..the adaption register will still have the gradient, volume and boudary functions that i specified earlier.

the thing is...the grid size is refined. the thing that i'm not sure of is...how do fluent distribute this grids eventhough an error message pops out and also what is the cause for that error message to pop up. thanks guys...

-nurul
  Reply With Quote

Old   September 3, 2001, 01:46
Default Re: floating point error during grid adaptation
  #2
John C. Chien
Guest
 
Posts: n/a
(1). You probably need to track down the person who wrote that section of the code in the first place. (2). You might want to find out whether it is caused by the precision of math used, single precision vs double precision math. Is you code using double precision math. This is usually the first step in the debugging. (3). And it is also likely that the programmer forgot to check the denominator of a division operator in the code. Floating point error is just a Fortran error.(I am not sure whether you will get the same error message using other languages, such as c, C++.)
  Reply With Quote

Old   September 5, 2001, 20:15
Default Re: floating point error during grid adaptation
  #3
david
Guest
 
Posts: n/a
These might help A) if you get the error for single precision, try double precision next time and vice versa B) Adapt based on ONE solution parameter at a time, then run few iterations and adapt again based on other C) Limit the refinement, so that it's not getting too big.

DC
  Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
On grid independent solution for pulsatile flow David FLUENT 5 March 25, 2022 04:33
matching variable data with grid point data anfho OpenFOAM Programming & Development 0 May 6, 2011 16:28
having a problem whit floating point error and it's solution m.beh FLUENT 2 November 9, 2010 11:28
Floating point error Sohail Ahmed FLUENT 0 March 12, 2004 01:02
Grid Independent Solution Chuck Leakeas Main CFD Forum 2 May 26, 2000 12:18


All times are GMT -4. The time now is 05:34.