On a reduced mixed s-v least-squares finite element formulation for the incompressible Navier-Stokes equations

In the present work a mixed finite element based on a least-squares approach (LSFEM) is proposed. We consider a formulation for Newtonian fluid flow, which is described by the incompressible Navier-Stokes equations. The starting point is a div-grad three-field first-order system with stresses, velocities, and pressure as unknowns. Following the idea in CAI et al. [1], this three-field formulation can be transformed into a reduced stress-velocity (s-v) two-field formulation, which is the basis for the associated minimization problem. In order to show the applicability of the considered approach a numerical example is presented at the end of the paper. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)