Equivalent Viscosity of Plasma and Plasma Substitutes in Oscillatory Flow

Womersley´s theory of oscillatory flow has been used to determine the equivalent viscosity (analogous to the apparent viscosity under steady flow conditions) of plasma and plasma substitutes (dextrans) of various molecular weights in rigid cylindrical tubes of radii ranging from 0.0304 to 0.162 cm. It is shown that the equivalent viscosity of dextran solutions is radius independent and is higher than that of plasma, at all frequencies. The continuum theory of suspensions, developed by Kline and Allen, is shown to be in good agreement with these findings.