VELOCITY PROFILES OF SLOW BLOOD-FLOW IN A NARROW TUBE

A fractal model is introduced into the slow blood motion. When blood f lows slowly in a narrow tube, red cell aggregation results in the form ation of an approximately cylindrical core of red cells. By introducin g the fractal model and using the power law relation between area frac tion phi and distance from tube axis rho, rigorous velocity profiles o f the fluid in and outside the aggregated core and of the core itself are obtained analytically for different fractal dimensions. It shows a blunted velocity distribution for a relatively large fractal dimensio n (D similar to 2), which can be observed in normal blood; a pathologi cal velocity profile for moderate dimension (D = I), which is similar to the Segre-Silberberg effect; and a parabolic profile for negligible red cell concentration (D = 0), which likes in the Poiseuille flow.