Newtonian and non-newtonian blood flow over a backward-facing step–a case study

In this work, the fluid flow over a 2D backward-facing step is analyzed in order to provide a case study for the use of different models for the blood dynamic viscosity in COMSOL Multiphysics. Three non-Newtonian models, as well as the Newtonian model are used to study the shear stresses and the reattachment length as a function of the fluid speed. The non-Newtonian models used in this study are the Carreau model, the power law model, and one of its variants, the Walburn-Schneck model. For the models studied, a transition from a Newtonian to a non-Newtonian behavior is observed as the center line speed is decreased.