An analysis of flow over a backward-facing step by an assumed stress mixed finite element method.

In this paper, a detailed analysis of flow over a backward facing step is presented for two types of outlet boundary conditions (1) traction free and (2) zero vertical velocity and zero horizontal traction, and for Re numbers up to 229. The computational scheme that is used is a mixed finite element method based on 'assumed deviatoric stress, pressure, velocity'. In this model, the final finite element equations involve the nodal velocities and the constant term in the pressure field in each element as unknowns. The convective accleration term is treated via a standard Galerkin scheme. (A)