Ship boundary conditions

Bernardo

I'm a student, newly with CFD. I'm working with Fluent 6.2, studying the wake of a chemical tanker. Wich type of inflow/outflow boundaries I must set in the VOF mode? I'm not able to solve the question: there is water under the waterline, and I want this water move at 13.5 knots, and the waterline at the inflow surface must be the same. Air may be steady. The computer understand so: a wall of air is incoming from inflow,sweep all the water and the hull run in the free air. Or so: all water coming from inflow, reverse on the deck and the ship becomes a submergible. Another doubt: the problem is steady or unsteady? Thanks Bernardo