  Methods of Computational Fluid Dynamics are applied to simulate pulsatile
blood flow in human vessels and in the aortic arch. The non-Newtonian behaviour
of the human blood is investigated in simple vessels of actual size. A detailed
time-dependent mathematical convergence test has been carried out. The
realistic pulsatile flow is used in all simulations. Results of computer
simulations of the blood flow in vessels of two different geometries are
presented. For pressure, strain rate and velocity component distributions we
found significant disagreements between our results obtained with realistic
non-Newtonian treatment of human blood and widely used method in literature: a
simple Newtonian approximation. A significant increase of the strain rate and,
as a result, wall sear stress distribution, is found in the region of the
aortic arch. We consider this result as theoretical evidence that supports
existing clinical observations and those models not using non-Newtonian
treatment underestimate the risk of disruption to the human vascular system.
