Finite element analysis of laminar viscous flow over a step by the penalty function formulation

Two types of quadratic rectilinear elements were used in applying the NASTO code to simulating flow over a backward facing step. The solution techniques comprise the Galerkin method and a penalty function formulation, the latter to eliminate the pressure term. The discretization was carried out with eight-node isoparametric elements of the 'Serendipity' family and nine-node elements of the Lagrange family. Both element sets were subjected to biquadratic interpolation. The runs were initiated with a parabolic velocity profile and an assumption of zero pressure at the exit. The results indicate that nine-node elements are more effective for two-dimensional flow representations.