IMPLEMENTATION OF SLIP BOUNDARY CONDITIONS IN OPENFOAM

Wall slip is a relevant phenomenon in many engineering processes, especially those involving long molecular chain materials, as happens, for example, in polymer processing. In order to get accurate predictions, numerical modelling tools must be able to cope with the relevant constitutive equations and the main flow phenomena involved. The currently available OpenFOAM codes have already a slip boundary condition implemented, in which the velocity at the wall channel is proportional to the neighbor cell velocity component tangent to the wall, i.e., are not based on any physical model devised for wall slip. This work describes the implementation and verification of linear and non-linear Navier slip boundary conditions in OpenFOAM. The numerical code implementation is verified against analytical solutions of the Couette and Poiseuille flows for Newtonian and viscoelastic fluids.