Boundary Condition
 

When we study papers, we see two kinds of boudary condition for momentum eqs. in free flow. we have some conditions for component of velocity or a condition for pressure such as constant pressure. But I know that in the case of pressure constant, I need the component of velocity in the boundary of computational domain. What is the method of calculating of velocity components in the boundary when the pressure is constant over it.

Re: Boundary Condition
 

When pressure is specified over the boundary (usually outflow condition), the velocities are extrapolated from grid points adjacent to the boundary.