Applications of FSI for Cardiovascular Haemodynamics - Computational Hemodynamics: Theory, Modelling and Applications - page 269

Fig. 8.34 Meshing of calcified carotid bifurcation. The isometric view of the mesh for entire
length of carotid bifurcation and a zoom-in view of the calcified plaque gives an indication of the
mesh resolution required for blood-plaque interaction simulation

8.5.2.2 Blood-Vessel-Plaque Model Setup

The partitioned approach was used to implement the FSI where coupling was per-
formed until convergence of interface variables (displacements and pressure) is
reached per time step. At each coupling loop, calculation of blood flow was initi-
ated. The calculated pressure field was then transferred and used as an applied force
in the structural domain to calculate the artery deformation. The tolerance for the
interface variables was 1E-4. The blood flow was modelled as laminar where the
highest Reynolds number reaches approximately 1000 in the stenosis region. The
time step size was set to 0.015 s and the results were obtained at the 4th cycle to
avoid any startup effects from a transient simulation.
In the solid domain, each artery end (CCA, ICA, ECA) were modelled as fixed
supports while a symmetry condition was assumed at the plane of the bifurcation. In
the fluid domain, the inlet boundary condition was a time-varying waveform (Tada
and Tarbell 2005) while the outlet boundary conditions at the ICA and ECA were
time-varying mass flow rates (Fig. 8.35 ). A smooth, no slip condition was speci-
fied at the artery wall. In this work, the arterial wall was modelled as a Hookean
and isotropic material for computational simplicity(Salzar et al. 1995; Thubrikar
and Robicsek 1995). The blood properties were also simplified as Newtonian fluid.
Both blood and artery properties are shown in Table 8.6 .