Analysis and Optimization of Inlet and Outlet Boundary Conditions for Flow Simulations in Circle of Willis

Abstract

Blood flow simulation of complex arterial networks in three-dimensions generally involves assigning multiple inlets and outlets. This work investigates different kinds of boundary condition assigned on inlets and outlets in the Circle of Willis. These boundary conditions will be adopted in a way that a realistic velocity profile and pressure in the main brain arteries are achieved. The result of this work will be used for Fluid-structure interaction simulations. As the force applied on the artery wall depends on the blood pressure, the goal is to achieve a pressure boundary condition based on the in-vivo flow rates in each artery.

Numerical investigation of hemodynamic pattern in carotid artery dynamic aneurysm on bifurcation region for early clinical decision making

“…The ability of effectively simulating the flow and pressure in a carotid artery is essential for researchers to either model the performance of medical devices or predict the evolution of a vascular pathology (Gharahi et al, 2016). The formation and advancement of atherosclerosis are caused by key factors such as localized hemodynamics in carotid artery and its geometric variables (Akai et al, 2004; Alimi & Wünsch, 2017; Liu et al, 2015; Studinger et al, 2003; Taylor et al, 1998) which may lead to stroke or even death at extreme situations like any other vascular diseases. This work aims to show that CFD is an effective tool that can provide better insights into CAB region study with proper solver settings and a numerical protocol.…”

“…The pulsatile flow profile is like the profile from Moore Jr et al (1992), also it was observed that the change in diameter is proportional to the velocity of the flow. The effect of various types of outlet boundary conditions for blood flow has been presented in Alimi and Wünsch (2017), Vignon‐Clementel et al (2010), Torii, Oshima, et al (2009) and Sun et al (2015). The type of boundary condition has considerable effect on the blood flow in an artery (Liu et al, 2015).…”

“…The type of boundary condition has considerable effect on the blood flow in an artery (Liu et al, 2015). There are various methods to determine the outlet boundary conditions such as complex Windkessel model (Du et al, 2015), circle of Willis (Alimi & Wünsch, 2017) lumped parameter outflow boundary condition (Vignon‐Clementel et al, 2010). The detailed discussion on these models are out of the scope of the present work and instead of implementing the above theoretical models, the current work uses experimental values from Jiang et al (1995) work.…”

“…The type of boundary condition has considerable effect on the blood flow in an artery (Liu et al, 2015). There are various methods to determine the outlet boundary conditions such as complex Windkessel model (Du et al, 2015), circle of Willis (Alimi & Wünsch, 2017) lumped parameter outflow boundary condition (Vignon-Clementel et al, 2010).…”