Stirred tank convergence issue

gurpreet89 · January 16, 2014, 23:26

hi friends
i am simulating a stirred tank using mrf in ansys 14.0 . i am using SIMPLE presure -velocity and first order discretization scheme, once it partially converge then i switch to QUICK..I am able to converge to 10^-3 but i want it to converge till 10^-4. the problem is that all the errors in residuals goes to 10^-4 exept for 'epsilon'.what should i do.plz help

gurpreet89 · January 17, 2014, 04:46

the convergence graph is something like this

can i say that i converged it to 10^-4 .i did around 9000 iterations

Eakarach · March 4, 2014, 14:50

Try to reduce the relaxation factor for turbulent quantities. I hope it can be help you.

Regards
Eakarach

ghost82 · March 5, 2014, 05:20

Hi,
it seems converged to me; try to create some monitor surfaces and monitor some variables such as velocity for example; if that variable doesn't change solution is converged.

Daniele

January 16, 2014, 23:26	Stirred tank convergence issue	#1
gurpreet89 New Member Gurpreet Join Date: Sep 2013 Posts: 16 Rep Power: 12	hi friends i am simulating a stirred tank using mrf in ansys 14.0 . i am using SIMPLE presure -velocity and first order discretization scheme, once it partially converge then i switch to QUICK..I am able to converge to 10^-3 but i want it to converge till 10^-4. the problem is that all the errors in residuals goes to 10^-4 exept for 'epsilon'.what should i do.plz help

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January 17, 2014, 04:46		#2
gurpreet89 New Member Gurpreet Join Date: Sep 2013 Posts: 16 Rep Power: 12	the convergence graph is something like this can i say that i converged it to 10^-4 .i did around 9000 iterations

March 4, 2014, 14:50		#3
Eakarach Member Join Date: Aug 2013 Location: Bangkok Posts: 32 Rep Power: 12	Try to reduce the relaxation factor for turbulent quantities. I hope it can be help you. Regards Eakarach

March 5, 2014, 05:20		#4
ghost82 Senior Member Rick Join Date: Oct 2010 Posts: 1,016 Rep Power: 26	Hi, it seems converged to me; try to create some monitor surfaces and monitor some variables such as velocity for example; if that variable doesn't change solution is converged. Daniele