Outlet pressure BC for highly unsteady and nonuniform outflow
 

Hi,

I'm using a solver similar to interDyMFoam/pimpleDyMFoam for a study which involves highly unsteady and nonuniform flow through the outlet boundary. What can be the best outlet BC for pressure for this kind of situation?

Is it possible to use groovyBC or by some other means to prescribe a value for pressure gradient at the boundary using the latest calculated value of the velocity field, e.g. dp/dn = nu*laplacian(u_n) - d(u_n)/dt - u.grad(u_n) where n indicates the local normal vector/direction?

Thanks