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francescov June 14, 2012 16:03

stirred vessel
 
hi all,
i'm new with cfx and i'm trying to simulate a multiphase liquid-liquid stirred tank.
i began with a simple single phase model, but the solver fails because it finds a non zero normal component of the velocity of the rotating mixer shaft. this is due, I think, to the low quality triangular mesh of the shaft itself, which doesn't reproduce the curvature of the cylindrical element. Is there any mesh method to overcome this problem? i tried to convert the 3 node surface tri element with a 6 node surface element, but it seems that ICEM can't generate the volume mesh elements.
I've attached the icem cfd file.
Anyone can help me?

Best Regards,

Francesco

ghorrocks June 14, 2012 19:15

Quote:

Is there any mesh method to overcome this problem?
Isn't that obvious? You need to improve mesh quality. Specifically you need a finer mesh which resolves the shape better.

CFX (or just about any other CFD solver) cannot use "high order elements" like FEA does, so forget about the 6 node surface elements. Finite volume CFD solvers put the high order numerics in the discretisation scheme, not the element formulation.


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