A dissipative particle dynamics simulation of a pair of red blood cells in flow through a symmetric and an asymmetric bifurcated microchannel

Particle-based methods such as smoothed particle hydrodynamics and dissipative particle dynamics are apt for simulating particle-like suspensions in blood. The blood flow through the microvasculature and its dynamics is strongly influenced by the dominant suspensions, and the red blood cells (RBCs) in plasma. The deformation dynamics of RBCs flowing through capillaries is of practical importance to be able to exploit the understanding for device development. In the present study, dynamics of a pair of RBCs flowing through a symmetric and an asymmetric bifurcating microfluidic channel are simulated. The finite-sized dissipative particle dynamics framework in conjunction with a discrete model for the RBCs is employed to model the system. When the RBCs flow through a bifurcating channel, the cell shape, deformability and flow rate ratios through the daughter branches are investigated. The deformed shape of RBC at the bifurcating channel’s tip was found to compare well with experimental observations. It was found that for flow through an asymmetric bifurcating channel, RBC near the separating streamline passed through the low flow rate branch, although lateral migration was observed. The trade-off effects and following effects of the two RBCs were particularly noticed in symmetric bifurcation. In the case of RBCs moving as a pair, it was found that the cell–cell interactions influence the path selection of RBCs as it approaches the tip of bifurcation. Specifically, RBC motion towards the low flow rate branch was observed.