CFD Analysis of Pulsatile Non-Newtonian Blood Flow in a Multi-Staged Stenosed Bifurcated Carotid Artery

Abstract

Accumulation of plaque on the arterial walls leads to a cardiovascular condition known as Atherosclerosis. This leads to lumen stenosis, and when it occurs in the carotid artery, it can impede the blood-flow to the face, brain, and neck, potentially leading to a stroke. The aim of this paper is to provide a comprehensive study of the carotid artery under multiple stenosed conditions using Computational Fluid Dynamics. In this study, blood has been considered to be a non-Newtonian fluid exhibiting pulsatile flow based upon the Carreau model and a two-dimensional bifurcated human carotid artery has been modelled. The Navier-Stokes equations-based FVM (Finite Volume Method) is used to analyze the flow inside the artery, while RANS k-ω SST turbulence model has been applied in the analysis of parameters of blood under stenosed conditions. Four models based on different stages of stenosis (0%; 25%; 50% and 75%) have been developed with simulations run on Ansys to find the effects under stenosis. For all the simulations, 65:35 flow division has been used, indicating that 65% of the total blood flows through the Internal Carotid Artery and 35% flows through the External Carotid Artery. Velocity and pressure contour, velocity distribution on the modelled plane and wall shear stress on arterial walls are the primary parameters studied at varying timescales of a cardiac cycle. As the stenosis stage increases, the flow separation can be predicted with higher accuracy. With the help of these parameters, one can build and design better treatment choices, such as designing of stents with different materials or adding of Ag-Au (Silver - Gold) nanoparticles in the blood to change the hemodynamics.