Numerical investigation on red blood cell dynamics in microflow: Effect of cell deformability

The radial dispersion of red blood cells (RBCs) near the vessel wall can significantly affect the transport dynamics in small vessels. The radial dispersion of RBCs is mainly caused by collisions between RBCs and this can be enhanced by aggregation. The objective of this study is to numerically investigate on the effect of RBC deformability on the radial motion of individual RBCs in a range of flow rates. Immersed Boundary - Lattice Boltzmann Method was utilized to study the radial motion of RBCs in a two-dimensional flow domain. The RBC flow simulations were performed at 40% hematocrit in a microvessel with diameter of 25μm and length of 100μm. The dispersion of less deformable RBCs was notably greater than that of normal RBCs at all flow rates and this effect seemed to be more pronounced when the flow rate was increased. The cell dispersion was higher near the vessel wall than the flow center regardless of flow rate and RBCs deformability. Thus, the dispersion of RBCs could be enhanced with flow rate and RBC rigidity. Our findings would be especially useful in investigating blood flows in arterioles and venules.