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-   -   solver settings, residuals plateau for a long time (http://www.cfd-online.com/Forums/cfx/24926-solver-settings-residuals-plateau-long-time.html)

Mumawalde December 14, 2007 16:15

solver settings, residuals plateau for a long time
 
Hello,

I have a question regarding solver settings in the k-e model with all of the default settings. I have a case that is primarily pipe flow. I setup my case of about 500000 nodes and allow it calculate. I am using scalable wall functions and acceptable yplus values. And, my results look great.

My question is that of time. When I start the case, it iterates for approximately 60 iterations with the residuals falling to levels of about 1.5E-04 then the residuals begin to level out. It then can take 100 more iterations to go down to the default threshold of 1E-04. The curve is monotonic and well behaved.

Does anyone know of a setting that can be used to help remove this asymptotic behavior and allow the solution to converge to accpetable levels sooner. Or, does anyone have experience with a case that behaves as explained, and know if ending the case early is an acceptable solution to saving time?

Thanks in advance for you help.

Glenn Horrocks December 16, 2007 17:47

Re: solver settings, residuals plateau for a long
 
http://www.cfd-online.com/Wiki/Ansys...gence_criteria

Glenn Horrocks

Mumawalde December 17, 2007 09:49

Re: solver settings, residuals plateau for a long
 
Thanks!


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