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.

http://www.cfd-online.com/Wiki/Ansys...gence_criteria

Glenn Horrocks

Thanks!