A Computational Study of Flow Instabilities in Aneurysms

AbstractThe majority of hemorrhagic strokes are caused by cerebral aneurysms, harboured in a large portion of the human population. Currently, it is unclear what constitutes a dangerous aneurysm, and the risk of rupture of such aneurysms is challenging to quantify. Previous studies have shown that flow dynamics play an important role in the development of aneurysms. However, there is varying consensus on blood flow patterns and stability. In this work, we formulate a Reynolds–Orr method to quantify the stability of blood flow in arteries. Applying this method to blood flow in four different arterial models, we find that the blood flow therein is unstable under physiological conditions. We show the most unstable eigenmodes for each of these models and discuss how they potentially could help explain the initiation and growth of aneurysms.