A computational fluid mechanical study of blood flow in a variety of asymmetric arterial bifurcations.

In the present study, the results of an attempt to estimate the flow field at arterial bifurcations are shown and discussed with respect to the pathogenesis of vascular disorders. The Navier-Stokes equations for incompressible Newtonian fluid flow were solved using a finite volume method with a body-fitted coordinate (BFC) system. The arterial models had various branching angles and mother-daughter diameter ratios. The boundary conditions specified are: steady and pulsatile fully developed flow at the inflow cross-section and a non-slip condition at the rigid wall. Results obtained were displayed using color computer graphics and an animation technique. Complex vortices were always found at the bifurcation regardless of the branching angle. At the proximal region of the bifurcation, where the early atherosclerotic plaque usually develops, strong unsteady vortices were found to access the wall in the diastolic phase. Therefore it is necessary to take them into account when discussing the development of atherosclerosis.