Figure 10

Helical graft. Flow mixing visualization by bolus injection into water flow (Re = 550) in U-tubes with (a) a conventional tube, and (b) a helical tube. Significantly greater mixing can be observed in the helical tube, which can enhance fluid-wall mass transport and render the spatial distribution of WSS relatively uniform in curved conduits. (c) angiogram of an arteriovenous access PTFE helical graft. Angiographic examinations have suggested that there exists reduction of helical geometry at or after implantation, which might be attributable to graft elongation under arterial pressure (taken from [136, 137] with permission).