Error in the solver !!! what does this mean...

eleazar · September 3, 2010, 03:07

Hello

does anyone knows what is this error?

server error: a floating point exception has occured: floating point exception [invalid operation]. The specific cause cannot be identified. Potential causes may include : (a) solution divergence due to poor mesh quality, crude initiliazation, etc, or (b) errors in the user-defined code or field fuctions.

thanks

bengy · September 3, 2010, 06:15

-use smaller time-step in your simulation (it have to work but time of computation will be longer)
-you can solve this problem on numerical way (underrelaxation factors etc.)
-improve mesh quality
-and/or chack (also possible) eg.capital font, sign (_ / -) in name of field function

regards

eleazar · September 3, 2010, 08:34

Quote:

Originally Posted by bengy

-use smaller time-step in your simulation (it have to work but time of computation will be longer)
-you can solve this problem on numerical way (underrelaxation factors etc.)
-improve mesh quality
-and/or chack (also possible) eg.capital font, sign (_ / -) in name of field function

regards

well i do not have any sign (_\ etc)

i activate the ramp method to linear ramp
and apply a courant number 2

the mesh is ok

any other idea>????

thanks

bengy · September 3, 2010, 10:04

courant number should be between 0.5 - 1.
let's try with smaller time step

eleazar · September 4, 2010, 03:15

well i am having the same error

i am trying to do a transonic simulation of a missile model
and i follow the example but in 3d model, can i find any pre file with an axable like this????

i believe this is better option.

please any help on that

bengy · September 4, 2010, 05:10

how large is your time step?
how many elements your mesh have?
where did you prepare mesh? (star-ccm+ or external soft?)
what kind of mesh do you have?(conformal or non-conformal?)
you have to sent more info about your simulation (physical model, expected value of solution-temp, velocity ec)

siara817 · January 12, 2011, 07:42

Divergence of the solution is the situation where cell residuals increase from one iteration to another. If left unchecked, this will eventually result in a floating point exception being reported.
I found it in the help of the software

abdul099 · January 15, 2011, 08:05

Just go to the solver manager and tick the box "Temporary storage retained". This will prevent the solver from deleting temporay values when a iteration is complete.
With this option, you will have more field functions available, e.g. residuals, gradients etc...
So create a scene and check the residuals, it can give you an evidence where the problem could be located.

September 3, 2010, 03:07	Error in the solver !!! what does this mean...	#1
eleazar Member Elena Cortin Join Date: Mar 2009 Location: Paris Posts: 65 Rep Power: 17	Hello does anyone knows what is this error? server error: a floating point exception has occured: floating point exception [invalid operation]. The specific cause cannot be identified. Potential causes may include : (a) solution divergence due to poor mesh quality, crude initiliazation, etc, or (b) errors in the user-defined code or field fuctions. thanks

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September 3, 2010, 06:15		#2
bengy New Member Join Date: Jul 2010 Posts: 29 Rep Power: 15	-use smaller time-step in your simulation (it have to work but time of computation will be longer) -you can solve this problem on numerical way (underrelaxation factors etc.) -improve mesh quality -and/or chack (also possible) eg.capital font, sign (_ / -) in name of field function regards

September 3, 2010, 10:04		#4
bengy New Member Join Date: Jul 2010 Posts: 29 Rep Power: 15	courant number should be between 0.5 - 1. let's try with smaller time step

September 4, 2010, 03:15		#5
eleazar Member Elena Cortin Join Date: Mar 2009 Location: Paris Posts: 65 Rep Power: 17	well i am having the same error i am trying to do a transonic simulation of a missile model and i follow the example but in 3d model, can i find any pre file with an axable like this???? i believe this is better option. please any help on that

September 4, 2010, 05:10		#6
bengy New Member Join Date: Jul 2010 Posts: 29 Rep Power: 15	how large is your time step? how many elements your mesh have? where did you prepare mesh? (star-ccm+ or external soft?) what kind of mesh do you have?(conformal or non-conformal?) you have to sent more info about your simulation (physical model, expected value of solution-temp, velocity ec)

January 12, 2011, 07:42		#7
siara817 Senior Member siamak rahimi ardkapan Join Date: Jul 2010 Location: Copenhagen, Denmark Posts: 220 Rep Power: 17	Divergence of the solution is the situation where cell residuals increase from one iteration to another. If left unchecked, this will eventually result in a floating point exception being reported. I found it in the help of the software

January 15, 2011, 08:05		#8
abdul099 Senior Member Join Date: Oct 2009 Location: Germany Posts: 636 Rep Power: 21	Just go to the solver manager and tick the box "Temporary storage retained". This will prevent the solver from deleting temporay values when a iteration is complete. With this option, you will have more field functions available, e.g. residuals, gradients etc... So create a scene and check the residuals, it can give you an evidence where the problem could be located.