I have used a MATLAB finite difference code to solve a lid driven cavity flow, based on a Stream function-Vorticity formulation of the viscous, incompressible Navier Stokes equations. Details about the method can be found here.
I want to change the code to simulate the flow around a square box in a rectangular domain, where the flow is uniform on the left side, and the flow is limited by the horisontal walls on the top and bottom. However, on the right side of the domain, where the flow exits, I have no idea how to express the boundary conditions.
How can I express the boundary conditions on the right side? Is it even possible for this method?