what is the outflow and inflow pressure boundary conditions, inthe flow past a backstep (unsteady laminar)using vorticity_stream function formulation

I'm not understanding.

For stream function vorticity method, the pressure is removed from the problem mathematically. That's one of the advantages of the method; you don't have a pressure to put BC's on. You specify boundary conditions on the stream function and vorticity.

i know, but after solving for the stra and vorticity iwant to calculate the pressure field