A numerical study of non-Newtonian blood flow in stenosed coronary artery bypass with grafts

Abstract

We investigate the behaviour of the pulsatile blood flow in a stenosed right coronary artery with a bypass graft. The human blood is assumed as a non-Newtonian fluid and its viscous behaviour is described by the Carreau model. The transient phenomena of blood flow through the stenosed region and the bypass graft are simulated for five cardiac cycles by solving the three dimensional unsteady Navier--Stokes equations coupled with the non-Newtonian model. Effects of the time variations of pulsatile velocity and pulse pressure are taken into account. The influence of the bypass angle on the flow interaction between the jet flow from the native artery and the flow from the bypass graft is investigated. Distributions of velocity, pressure and wall shear stresses are determined under various conditions. The results show that the blood pressure in the stenosed artery drops dramatically in the stenosis area and that high wall shear stresses occur around the stenosis site.