Fluid dynamics of a textured blood-contacting surface

This study examined the fluid dynamics of a textured blood-contacting surfa ce using a computational fluid-dynamic modeling technique. The texture cons isted of a regular array of microfibers of length 50 or 100 mum, spaced 100 mum apart, projecting perpendicularly to the surface. The results showed t hat the surface texture sewed as a pow-retarding solid boundary for a lamin ar viscous pow, resulting in a lowered wall sheer stress on the base-plane surface. However, the maximum wall shear stress on the fibers was much high er than the shear stress on the nontextured base plane. Al all fractions of fiber height down past 10 mum, the permeability of the textured region gre atly exceeded the analytically predictable permeability of an equivalent ar ray of infinite-height fibers. The lowered surface shear stress appears to explain in part the enhanced deposition of formed blood elements on the tex tured surface.