Secondary effects in cone and plate viscometers

Article type: Research Article

Authors: Heuser, G.

Affiliations: Aerodynamisches Institut, RWTH Aachen

Note: [] Accepted by: Editor M. Schmid-Schönbein

Abstract: If one wants to use cone and plate viscometers to study the influence of shear stress on blood damage in low viscosity suspending media, then one platen has to be rotated at high speed. In this case centrifugal forces can no longer be neglected and they influence the flow conditions within the shearing regions. A solution for the radial pressure distribution is obtained. There is a good agreement between theoretical and experimental pressure distributions for Newtonian fluids. But the experimental results for blood show marked deviations from the Newtonian behaviour. Measuring the rate of haemolysis it is found that it depends distinctly on the gap width. The forces acting on the erythrocytes produce a shift in concentration in radial direction, which is detected by measuring the haematocrit values and is calculated by a balance of forces.

DOI: 10.3233/BIR-1978-153-418

Journal: Biorheology, vol. 15, no. 3-4, pp. 311-320, 1978