Tube flow behavior and shear stress-shear rate characteristics of canine blood

¹ Department of Nutrition, Food Science and Technology, Massachusetts Institute of Technology, Cambridge, and Medical Research Department and Medical Service, Beth Israel Hospital, Boston, Massachusetts

The shear stress-shear rate characteristics of canine blood were determined in a cone and plate viscometer and could be expressed by a power-law equation. The differences in the shear stress-shear rate and tube flow characteristics suggest a marginal gap of plasma at the tube wall. It also appears from these considerations that the gap width of plasma increases with tube diameter. Laminar flow considerations are insufficient for explaining tube flow behavior. High-speed motion pictures indicate collisions between cells in tube flow and the cells do not appear to remain in discrete streamlines. It is suggested that these uncalculated energy losses are the reason why tube flow behavior cannot be predicted from shear stress-shear rate information.