Coupling of Navier–Stokes equations with protein molecular dynamics and its application to hemodynamics‡

The red blood cell (RBC) aggregation plays an important role in many physiological phenomena, in particular the atherosclerosis and thrombotic processes. In this research, we introduce a new modelling technique that couples Navier–Stokes equations with protein molecular dynamics to investigate the behaviours of RBC aggregates and their e ects on the blood rheology. In essence, the Lagrangian solid mesh, which represents the immersed deformable cells, is set to move on top of a background Eulerian mesh. The e ects of cell–cell interaction (adhesive=repulsive) and hydrodynamic forces on RBC aggregates are studied by introducing equivalent protein molecular potentials into the immersed nite element method. The aggregation of red blood cells in quiescent uids is simulated. The de-aggregation of a RBC cluster at di erent shear rates is also investigated to provide an explanation of the shear-rate-dependence of the blood viscoelastic properties. Finally, the inuences of cell–cell interaction, RBC rigidity, and vessel geometry are addressed in a series of test cases with deformable cells (normal and sickle RBCs) passing through microand capillary vessels. Copyright ? 2004 John Wiley & Sons, Ltd.