On the shear-thinning and viscoelastic effects of blood flow under various flow rates

The aim of this paper is to describe and discuss the results of numerical comparative study performed in order to demonstrate and quantify some of the most relevant non-Newtonian characteristics of blood flow in medium-sized blood vessels, namely its shear-thinning and viscoelastic behavior. The models studied in this work are the classical Newtonian and Oldroyd-B models, as well as their generalized (shear-thinning) modifications. Numerical tests are performed on three-dimensional geometries, namely an idealized axisymmetric stenosis and a realistic stenosed carotid bifurcation reconstructed from medical images. The numerical solution of the system of governing equations is obtained by a finite-volume method on a structured grid. Model sensitivity tests are achieved with respect to the characteristic flow rate to evaluate its impact on the observed non-Newtonian effects. (C) 2010 Elsevier Inc. All rights reserved.