Steady Flow Studies of the Geometry Effects on the Recirculation Properties at the Iliac Bifurcation

Abstract

The characterization of blood flow patterns is an important task to establish links between hemodynamics and atherosclerosis development, one of the leading causes of death worldwide. Taking into account that the development of cardiovascular diseases and the disturbances in blood flow profiles are characteristic of each individual, the study of the effects of geometry and flow distribution is quite important. For this reason, in the present paper, a CFD numerical model for both simplified and real anatomic iliac bifurcation was developed, taking into account a steady velocity inlet profile. The results were analyzed, in terms of the recirculation zone length and location, but also in velocity and wall shear stress distribution. It was observed that the bifurcation angle does not affect significantly the recirculation properties. However, significant differences were achieved with different iliac diameters and bifurcation geometry. Moreover, outflow maldistribution in the iliac arteries leads to more complex flow patterns near the iliac bifurcation, intensifying reverse and asymmetric flow patterns. The results of the simulation using the realistic model geometry confirmed that the regions of the geometry prone to develop recirculation areas occur, preferentially, downstream the bifurcation at the outer walls of iliac branches. In brief, this study allowed a better understanding of the relationship between hemodynamics and vascular diseases, through assessing the distributions of blood velocity and biomechanical forces imposed on the arterial wall by the blood.