Comparison of Newtonian and Non-Newtonian Blood Flow in an Ascending Aortic Aneurysm

Abstract

This work aimed to perform a numerical study of aortic hemodynamics and evaluate both Newtonian and non-Newtonian blood flow parameters in an ascending aortic aneurysm model. An aortic model was reconstructed from a medical computed tomography (CT) image, and finite element method laminar blood flow modelling was performed using different blood parameters. The inflow boundary conditions were defined as a flow profile, and the outlet boundary conditions were defined as the pressure at each outlet. The first simulation was calculated by considering blood as a Newtonian fluid, while in the second simulation, using the Carreau model, blood was assumed to be a non-Newtonian fluid. The results showed that average systolic and diastolic velocities were 2% and 9% higher, respectively, for the non-Newtonian fluid. In addition, the wall shear stress (WSS) values on the surface of the aneurysm were 30% higher during systole in the non-Newtonian simulation, while the average WSS on the artery surface in diastole was 20% higher for the Newtonian fluid.