Problem with VOF Solution Fluent 6.3.26
 

Hello,
I am working on a VOF simulation where liquid steel flows out of a furnace through a slide gate with different opening situations. For every slide gate position i have two different starting conditions. Calculation #1 startes with an empty pipe below the slidegate ( just air in it ), and calculation #2 startes with steel in this region. We want to see how the steel in the pipe gets out and the air is sucked in. Calculation #1 always runs well but we have situations with the fullfilled pipes where no air is sucked in ( also the slidegate position does not allow that high massflow that would make this possible ). I am working with a rke turbulence modell, constant density of both fluids air and steel and Piso, Presto and second order discretisation.
Any ideas ?
Thank you
Gernot