Question

1. Blood has a variable viscosity at 37 °C that depends on the percent composition of hematocrit and plasma. A small sample of blood is tested in a viscometer and the following results are obtained: (Shear stress (Pa), Shear rate (s^-1))

(0.0235, 2.25)

(0.0396, 4.5)

(0.0787, 11.25)

(0.1324, 22.5)

(0.2227, 45)

(0.3746, 90)

(0.7447, 225)

(1.2524, 450)

(a) Determine the viscosity of the blood sample using the power law equation for non-Newtonian fluids. (b) Indicate from the value of the power you have determined for the power-law fluid what type of fluid blood is: a Bingham plastic, dilatant, Newtonian or pseudoplastic?

Answer 1

In (shear sress) vs In (shear rate) tu (dv/dx)An t-shear stress Shear stress shear rateIn In (dv/dx) 2.25 3.75075 0.81093 4.5 -3.22893 1.504077 (i) 0.0235 0.0396 0.0787 11.25 2.54211 2.420368 0.1324 0.2227 0. 374б 0.7447 1.2524 y 1.332x +5.808 uE viscosity dv/dx shear rate 22.5 -2.02193 3.113515 45-1.50193 3.8066б2 90 0.9819 4.49981 225 -0.294775.4161 450 0.225062 б. 109248 take In of equation (i) In (shear sress) vs In Int Inu+n In(dv/dx) (shear rate) Linear (In (shear sress) vs In (shear rate)) from the equation InH 5.808 then H 333 Pas n 1.332 it is graeter than 1 so it is dilatant .4 .3