A parametric (inlet) flow analysis of 3D human carotid artery using realistic geometry

In this study the biomechanical characteristics of a realistic carotid artery are studied numerically using different inlet velocity profiles. Sinusoidal and experimental data measured at the common carotid artery are used to generate the velocity inlet boundary conditions at common carotid artery. The generation is done using elliptic Womersley velocity profile technique. The computation domain is generated using a computed tomography (CT) data of a real patient. Three-dimensional (3D) transient NS equations are solved in this actual domain using the proposed boundary conditions. Effects of different input conditions on the results of the simulation are discussed. This study adds more results to the paper by the authors. Those new results include wall shear stress histories for all input data (cases). Main parameters investigated at the critical parts of the carotid artery such as bifurcation and sinusoidal enlargement regions are velocity profiles, wall shear stress (WSS) and pressure distributions. Results show that the velocity inlet does not only change the magnitude of the mechanical properties but also changes the magnitude ordering between geometric points. Also there is a linear relation between velocity and WSS values. This relation is not broken at stenosis or sinus regions meaning that the relation is not affected by the geometry. But the relation between velocity and pressure is affected by the geometry of the artery. Shapes of the velocity histories at most of the selected points are very similar to the shape of the relevant inlet velocity histories while it is very different for some selected points. Study concludes that the input boundary conditions and slope/curvature discontinuities in the geometry affect the velocity, pressure and WSS distributions highly. The conclusion is supported by the development of secondary flow at inflexion regions and vortex at especially the sinus area.