Abstract: Flow visualization of a near wall flow is of great importance in the
field of biofluid mechanics in general and for studies of pathologic vessel
enlargements (aneurysms) particularly. Wall shear stress (WSS) is one of the
important hemodynamic parameters implicated in aneurysm growth and rupture. The
WSS distributions in anatomically realistic vessel models are normally
investigated by computational fluid dynamics (CFD). However, the results of CFD
flow studies should be validated. The recently proposed Wall-PIV method was
first applied in an enlarged transparent model of a cerebri anterior artery
terminal aneurysm made of silicon rubber. This new method, called Wall-PIV,
allows the investigation of a flow adjacent to transparent surfaces with two
finite radii of curvature (vaulted walls). Using an optical method which allows
the observation of particles up to a predefined depth enables the visualization
solely of the boundary layer flow. This is accomplished by adding a specific
molecular dye to the fluid which absorbs the monochromatic light used to
illuminate the region of observation. The results of the Wall-PIV flow
visualization were qualitatively compared with the results of the CFD flow
simulation under steady flow conditions. The CFD study was performed using the
program FLUENT®. The results of the CFD simulation were visualized using the
line integral convolution (LIC) method with a visualization tool from AMIRA®.
The comparison found a very good agreement between experimental and numerical
results.