Influence of Blood Rheology and Outflow Boundary Conditions in Numerical Simulations of Cerebral Aneurysms - Mathematical Methods and Models in Biomedicine - page 164

Fig. 12 Velocity (cm/s) and WSS (dyn/cm 2 ) magnitude for the clipped geometry coupled with the
1D model with time averaged unsteady and steady flow regimes, and corresponding differences

jet impingement and size of the swirling motion are apparent. This indicates that
the differences due to the rheological model choice do not only affect the near-wall
region, but in cases of complex recirculating flow the free-stream field may also be
effectively altered.

6 Conclusions

Two types of geometries were considered: idealized configurations of a curved
vessel with an aneurysm, where a side-branch in the aneurysm was included as a
tube or a hole, and an anatomically realistic geometry of a cerebral aneurysm with
side-branches removed.
Regarding the idealized geometries, both steady and unsteady inflow regimes
were considered. Several boundary conditions were prescribed at the outflow
section of the side-branch in the aneurysm. Results indicate a large influence
of the outflow conditions on the entire domain, but more pronounced near the
side-branch base. The reduced 1D and 0D models seem to be fair approaches
to take into account the presence of the side-branches, providing appropriate
pressure drops. The importance of considering the side-branch increases when
located close or in the aneurysm, as it was the case of the idealized geometry.