Date and Time: March 13, 2:45-3:35

Location: Thackeray 524

Speaker: Martina Bukač, University of Houston

Title: A stable partitioned scheme for fluid-structure interaction in blood flow

Abstract:
We study arterial blood flow where the arterial walls are modeled using a linearly viscoelastic, cylindrical Koiter shell capturing both radial and longitudinal displacements. The fluid flow is modeled by the Navier-Stokes equations for an incompressible, viscous fluid. The two are fully coupled via the kinematic and dynamic coupling conditions. Classical partitioned schemes for the fluid-structure interaction problem are known to suffer from numerical instabilities if the fluid and structure are of comparable densities, which is the case in blood flow. We present a new model and a novel loosely coupled partitioned numerical algorithm based on a modified Lie operator splitting scheme that decouples the fluid and structure sub-problems, obtaining a scheme that is unconditionally stable. The accuracy and performance of the scheme were compared to a monolithic scheme, showing that the accuracy of our scheme is comparable to that of the monolithic scheme, while our scheme retains the main advantages of the partitioned schemes, such as modularity, simple implementation, and low computational costs. We applied this scheme to study blood flow in a healthy carotid artery and in a stenosed coronary artery. Our numerical results indicate the significance of longitudinal displacement also observed in recent experimental studies.