Navier Stokes, Pressure BC, Discretization

Sree

Dear All,

I have written a code for Stokes/NStokes based on discontinuous galerkin fem. Simulated some std test problems and code seems to work well. To deal with pressure, I fix the pressure at a point (to get rid of singularity) and use Dirichlet BC's everywhere to solve the eqn. Now I am interested in a situation where I can impose a pressure difference/drop across the domain and simulate the flow. I would like to know how can I do this (or in general how fem community do this), what boundary conditions to be used? in some commercial code like comsol etc. one can do this. but dont know how the equations and BC used there.Any help, pointers, reference etc. is appreciated. Thank you Sree