Proper(more stable) boundary condition for free surface problem
 

Hi
Im modeling a partially submerged body in ANSYS CFX. My simulation also contains cavitation, which makes the simulation more unstable.
According to attached picture which boundary condition is more stable from numerical point of view for the side wall and please tell why?

What are you modelling? Where is the cavitation? Is this a body floating on an infinite water body, or a body in a pipeline?

Hi
Its a partially submerged hydrofoil with a distinguished angle of attack which half of the chord is submerged in water. The cavitation occurs at the trailing edge of hydrofoil. which boundary condition is more stable for the side of my domain?

A wall, with a tangential velocity of the free stream velocity.