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wemendibe June 22, 2013 13:29

mixing tank
If I put 100 rpm rotational velocity to the impeller in the mixing tank it converge, but if I put 500 rpm it does not converge, do anyone knows why??
I put in viscous model k-epsilon RNG, because it is turbulent, I can say if anyone knows all the steps that I have.

Thank you

Mikel Mendibe

Far June 23, 2013 04:27

At off-design conditions you will have more separation and hence difficulty in converging steady state solution.

wemendibe June 23, 2013 05:19

So, do you mean that is normal to do not convege?

Far June 23, 2013 06:16

yes, if it is not a design condition. At off design conditions you may need to activate unsteady flow solver.

wemendibe June 23, 2013 06:32

Thank you. I have another question, I want that the wall of the tank heat the fuild that I have. I go to the wall and I put the temperature that I want, is it ok?

Thank you

Far June 23, 2013 06:39

yes. Also enable energy equation.

A CFD free user June 25, 2013 03:22

You should increase the impeller speed gradually untill to reach your desire speed. For instance, to do a simulation with 400 rpm, first start with 100, then increase it about 20 rpm and go ahead. once I had the same problem too. Try this it helps.

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