Freezing part of a solution to re-use as a boundary condition
 

Hi Folks,

I would like to perform a transient analysis of a water jet going into a tank.

What I have is a jet of water coming into a tank that is filled to some level with water. The inlet and outlet from the tank remain the same and are constant.

The jet will basically remain the same for the most part above the water. So once this area is computed I would like to freeze it and not waste the solvers time on it. Basically use it as a boundary condition.

Another motivating factor for me is that the cell size in the jet area is awfully small (in order to properly resolve the jet), so if I need to keep solving for it, my time step is limited by this area.

Does anyone know if this is possible with Star-CCM+? And if so can someone explain the basic method that needs to be used.