Numeric Simulation of Fluid–Structure Interaction in the Aortic Arch

Abstract

This paper presents a numeric simulation for a fully coupled fluid–structure interaction (FSI) of an anatomically accurate aortic arch from the aortic root immediately distal of aortic valve to the junction of the renal arteries. The aortic wall was simplified as a shell structure and assumed to be supported by virtual springs with adjustable stiffness. A structural finite element analysis of the vessel wall and a finite volume-based computational fluid dynamics model of the blood flow were used for the simulation. The blood flow was assumed to be turbulent and a k − ε / k − ω blended shear stress transport used for the turbulent flow. A pulsatile flow rate waveform (adopted from ultrasonic measurements) was prescribed at the inlet, and a pulsatile pressure waveform was imposed at the outlets. The wall shear stress and three-dimensional flow velocity, as well as the wall deformation and von-Mises stress distributions on the aortic wall over a cardiac cycle are presented. The flow pattern in the aortic arch is laminar at the ascending phase of systole but turbulent flow develops during the descending phase of systole. This phenomenon is consistent with in vivo measurements in canine and human models. It is concluded that the fluid–structure interaction model can provide physiological insight into the biomechanics of the aortic arch.