TY - JOUR T1 - Finite element approximation of flow of fluids with shear rate and pressure dependent viscosity A1 - Hirn, Adrian A1 - Lanzendörfer, Martin A1 - Stebel, Jan JA - IMA Journal of Numerical Analysis Y1 - 2012 VL - 32 IS - 4 SP - 1604 EP - 1634 N1 - Preprint NCMM No. 2011-001 UR - http://www.karlin.mff.cuni.cz/ncmm/preprints/115134735pr1.pdf M2 - doi: 10.1093/imanum/drr033 KW - error analysis KW - finite element method KW - non-Newtonian fluid KW - shear-rate- and pressure-dependent viscosity N2 - In this paper we consider a class of incompressible viscous fluids whose viscosity depends on the shear rate and pressure. We deal with isothermal steady flow and analyse the Galerkin discretization of the corresponding equations. We discuss the existence and uniqueness of discrete solutions and their convergence to the solution of the original problem. In particular, we derive a priori error estimates, which provide optimal rates of convergence with respect to the expected regularity of the solution. Finally, we demonstrate the achieved results by numerical experiments. To our knowledge, this is the first analysis of the finite element method for fluids with pressure-dependent viscosity. The derived estimates coincide with the optimal error estimates established recently for Carreau-type models, which are covered as a special case. ER -