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-   -   Results getting worse with higher Convergence (http://www.cfd-online.com/Forums/fluent/78977-results-getting-worse-higher-convergence.html)

rage August 9, 2010 01:36

Results getting worse with higher Convergence
 
Hi ,
Am a new member to this site. I am facing a problem when running iterations on fluent. In my problem, i expect a symmetric result but when i decrease the convergence limit from e-3 to e-4 the results becomes asymmetric which i know is not correct. Is it possible that in some cases result may get worsen when decreasing the convergence limit? Please help.

-mAx- August 9, 2010 02:32

maybe is your calculation not converged. Let iterate.
But if you are expecting a symmetric result, why don't you use symmetry?

rage August 9, 2010 02:53

thanks Max for the reply:) am not using symmetry because i want to test as to what grid size and convergence criterion can give right results, if it comes sym, i can rest assured that result id crct. please elaborate upon first part of ur reply. Thanks

-mAx- August 9, 2010 04:02

if your interest is a force or massflow or whatever, I would monitor this variable in function of iterations (solve/monitor/surface)
It will give you an idea if you get a converged solution or not. (residuals charts aren't sufficent)


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