floating point exception?

syd · March 30, 2010, 08:22

What's the meaning of "floating point exception"?

I set up a volume mesh and tried to run the solution: at this point, I got an error message about "154 negative volume cells", so I removed them with "Region->remove invalid cells".

After that I tried again to run the solution, but the message of the floating point exception appeared, without running any iteration...

Do you have any ideas of what the problem could be?

thank you!

Vinicius · March 30, 2010, 10:22

Hi,

Your simulation is diverging, this is the "meaning" of the floating point exception. One of its causes could be poor mesh quality. If you are using the polyhedral mesh, be sure that the surface mesh has a good quality and try to turn on the "Cell quality remediation" model in your physics continua. Also try to make another mesh, taking care at regions that have complex geometry or curvature.

Hope it helps,

Vinicius

Paulh · March 30, 2010, 15:18

You might also want to look for any non-contiguous regions. Chuncks of cells separated from the main Region will cause the solver to crash pretty quick.

nomad · April 20, 2010, 19:55

As a last resort, run a mem test on your RAM. Bad ram leads to round-off errors in the iteration results, that, over time, results in diverging trends.

March 30, 2010, 08:22	floating point exception?	#1
syd New Member Mattia Join Date: Mar 2010 Posts: 7 Rep Power: 16	What's the meaning of "floating point exception"? I set up a volume mesh and tried to run the solution: at this point, I got an error message about "154 negative volume cells", so I removed them with "Region->remove invalid cells". After that I tried again to run the solution, but the message of the floating point exception appeared, without running any iteration... Do you have any ideas of what the problem could be? thank you!

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March 30, 2010, 10:22		#2
Vinicius Member Vinicius Girardi Join Date: Mar 2009 Location: Sao Paulo, Brazil Posts: 80 Rep Power: 17	Hi, Your simulation is diverging, this is the "meaning" of the floating point exception. One of its causes could be poor mesh quality. If you are using the polyhedral mesh, be sure that the surface mesh has a good quality and try to turn on the "Cell quality remediation" model in your physics continua. Also try to make another mesh, taking care at regions that have complex geometry or curvature. Hope it helps, Vinicius

March 30, 2010, 15:18		#3
Paulh Member Paul Hancock Join Date: Mar 2009 Location: Bellingham, WA Posts: 31 Rep Power: 17	You might also want to look for any non-contiguous regions. Chuncks of cells separated from the main Region will cause the solver to crash pretty quick.

April 20, 2010, 19:55		#4
nomad Member John Join Date: Aug 2009 Posts: 92 Rep Power: 17	As a last resort, run a mem test on your RAM. Bad ram leads to round-off errors in the iteration results, that, over time, results in diverging trends.