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-   -   Error in the solver !!! what does this mean... (http://www.cfd-online.com/Forums/star-ccm/79763-error-solver-what-does-mean.html)

eleazar September 3, 2010 03:07

Error in the solver !!! what does this mean...
 
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 (Post 273877)
-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 08:42

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 09:05

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.


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