Study of incompressible flow over a backward facing step using a triangular penalty element

The numerical efficiency of the penalty formulation and a Newton-Raphson scheme (NRS) for modeling flows over a backward facing step is assessed. Details of the penalty model, a variational formulation with equilibrium and continuity conditions, the associated finite element discretization and precise, computationally intensive triangular elements are provided. The NRS is applied to generate solutions for the nonlinear phenomena incrementally for specific Reynolds numbers. A savings of 50 percent in computer time is attained compared to previous calculations with the NRS method. Further reductions, by a factor of three, are projected with refinements.