AXISYMMETRIC AND ASYMMETRIC BEHAVIORS OF A RED BLOOD CELL IN CAPILLARIES

The axisymmetric and asymmetric behaviours of a red blood cell (RBC) in capillaries are investigated numerically by developing a two-fluid model, in which the membrane force is considered to describe the RBC deformation. The quantitative validations with the experimental and theoretical results are provided, and good agreements are found in the deformation index and deformed RBC shapes. The present results show that the RBC experiences the axisymmetric motion if the membrane force is balanced between the RBC cusps, otherwise the asymmetric motion occurs. The characteristic parachute shape of deformed RBC is observed in the axisymmetric motion, while the tank-treading motion of RBC membrane is generated in the asymmetric motion. As the capillary diameter increases, the decrease in RBC length is accompanied by an increase in RBC width.