Hi, does anyone has ever simulate bubble column or other multiphase devices with fluent 6 ? How do you manage the free surface in Fluent ? Do you put a patch of air above the water, or do you have another solution to "degaze" the gas phase ? I've encounter problems in the 1st case with turbulent kinetic energy and dissipation, which goes to high value in 1 or 2 cells and make the calculation diverge !! I don't if it's due to a wrong calculation of velocity which induce this error !!

Help me please !! Thanx

If U R not concerned with air-water interface U can treat it as wall with shear stresses set equal to zero

you can choose vof model , but if you are using the known condition of water and air , choose symetry condition on the intersection of air-water surface.

Have any of the repliers actually read the original post? He wants a degassing condition.