Modelling of fluid-wall interactions for viscous flow in a stenotic elastic artery

This paper studies the oscillatory nature of wall shear stress as a result of a pulsatile flow and periodically excited wall. An unsteady Navier-Stokes (N-S) solver based on the method of operator splitting and artificial compressibility has been developed for the moving boundary problem to simulate blood flow through a compliant vessel. The code of the solver has been developed using Fasttalk, a high-level programming language in the Fastflo environment. Galerkin finite elements are used to discretize the governing equations. The analysis has been applied to the backward facing step and a time varying computational domain (2-D tube) as test cases for validation. The code is then applied to a physiologically realistic blood vessel based on the spring and dashpot model. The governing equation for the blood vessel is based on 2-D dynamic thin shell theory that takes into account the curvature of the stenotic portion of the vessel. Marching the solution towards steady state is considered to show the viability of the current technique. Several sample cases are presented with emphasis on the depiction of vortical flow details and wall shear stress. There has been no observable difference in vortical flow development when compared with the rigid stenotic model.