Optimum kinetic energy dissipation to maintain blood flow in glass capillaries: an analysis based on flow field determination by axial tomographic and image velocimetry techniques.

The video micrographic images of fully developed blood flow in a glass capillary of diameter 200 microns are recorded. These data after digitization are analyzed by an IBM PC/AT-based image processing system to obtain erythrocyte and velocity distribution profiles by axial tomographic and image velocimetry techniques, respectively. The results obtained show that the parabolic profile of erythrocyte distribution at hematocrit 10% becomes more blunt at 60%. A similar increase in bluntness at the various hematocrit is observed for the velocity profiles. For calculation of kinetic energy dissipation a set of erythrocyte distribution profiles at each hematocrit with a transition from existing to parabolic one by multiparametric analysis, are constructed. The results show that the existing profiles as obtained at all hematocrits dissipate minimum kinetic energy. Any deviation towards parabolic form leads to dissipation of higher amount of the energy.