Numerical Simulation of the Effects of Internal and External Viscosity Contrast of a Red Blood Cell in a Non-Newtonian Plasma on Its Motion and Suspension Rheology

Blood is composed of plasma, which is the liquid component, and red blood cells (RBCs), white blood cells, and platelets, which are the physical components. Plasma, the solvent portion of blood, is generally treated as a Newtonian fluid. However, plasma is known to exhibit non-Newtonian properties depending on the plasma protein content. RBCs are known to exhibit different behaviors in blood, namely, tank-treading, and tumbling motions. These motions are important for understanding the rheological properties of RBC suspensions because they have a significant effect on the apparent viscosity of blood. As a fundamental study, the effect of the reduced area of RBCs on their motion was investigated. Focusing on the non-Newtonian properties of plasma, the deformation behavior of single red blood cells in two-dimensional shear flow was analyzed. As a result, it was confirmed that the results in non-Newtonian fluid are different compared to the results in Newtonian fluid of others.