Theoretical analysis of flow properties of aggregating red cell suspensions in narrow horizontal tubes

Article type: Research Article

Authors: Murata, Tadayoshi

Affiliations: Department of Physics, Faculty of Science, Tokyo Metropolitan University, Minami Ohsawa 1-1, Hachiohji-si, Tokyo 192-03, Japan

Abstract: The flow properties of aggregating red cell suspensions flowing at low rates through horizontal tubes are analyzed using a theoretical model based on microscopic observations. It is assumed that aggregated red cells form a cylindrical core which is eccentrically located in a horizontal tube due to sedimentation in a steady-state. The cylindrical core surrounded by a uniformly dispersed suspension of individual red cells moves with a uniform velocity along the tube axes. The velocity distribution within the tube is calculated on the assumption of unidirectional, incompressible flow. From this result the relative viscosity is obtained as functions of the size, eccentricity and hematocrit of the core and a discharge hematocrit. It is shown that the relative viscosity increases monotonically with increasing the eccentricity. The simplified model also shows the presence of a certain condition under which the relative viscosity of aggregating red cell suspensions becomes lower than that of non-aggregating suspensions.

Keywords: red cell aggregation, rouleaux, blood viscosity, red cell sedimentation, microcirculation

DOI: 10.3233/CH-1994-14407

Journal: Clinical Hemorheology and Microcirculation, vol. 14, no. 4, pp. 519-530, 1994