(408a) Influence of Rheological Models in a Pulsatile Flow inside a Generic Carotid Artery Aneurysm with the Use of Computational Hemodynamics

Aneurysms are clinical conditions in which the arterial wall presents an abnormal dilatation, due to excessive blood pressure or a decrease in the blood vessel wall resistance. This type of condition can be often seen in intracranial arteries, such as the circle of Willis. Thus, once this aneurysm ruptures, it results in an internal hemorrhage in the subarachnoid space, which can consequently lead to death or morbidity of the patient. This possible life threatening condition is often asymptomatic and is believed to be originated due to hemodynamic forces in the arterial wall. Thus, in order to aid physicians, CFD-based (Computational Fluid Dynamics) tools can be used alongside medical imaging techniques to obtain key hemodynamic parameters, such as WSS (Wall Shear Stress) and velocity profiles. Given that blood is a suspension-type fluid, blood cells suspended in the plasma, it presents a non-Newtonian behavior. Although this behavior is widely known, many studies tend to model blood flow as being Newtonian. However, a Newtonian rheological model does not represent the real nature of blood. Since CFD simulations try to model cases as close as possible to its real behavior, a non-Newtonian approach might be more suitable. Therefore, this study aimed to compare and analyze the influence of rheological models on the blood flow in an idealized aneurysm in a generic carotid artery. Additionally, the simulations were carried using a pulsatile flow regressed from experimental data to further represent the real blood physics. All the simulations were done using a commercial code. Once the results were obtained, a comparison between a Newtonian and non-Newtonian approach was made, in order to assess the impacts of considering blood as being non-Newtonian. Moreover, a comparison among a few non-Newtonian rheological models was also made, with the objective of analyzing the Importance Factor, which states how far from a Newtonian behavior the fluid being studied is.