Dynamics of a red blood cell in high shear flow in physiological conditions of viscosity
In a recent joint work with biophysicists from the CBS lab at Montpellier, our group has presented numerical simulations of the dynamics of an isolated red blood cell in pure shear flow, in physiological conditions of viscosity, and at shear rates that had never been studied before. It has been shown that when incresing the shear rate, after the well-known tumbling and rolling dynamics, the red blood cell starts deforming and becomes first a stomatocyte, then a so-called trilobe, for shear rates higher than 500 s-1. This new dynamic shape has been revealed by our work. The following animation shows the dynamics of a red blood cell at viscosity ratio 5 in a pure shear flow of shear rate 1000 s-1. The vorticity direction is normal to the screen. After a transient dynamics, the red blood cell becomes a trilobe rotating in the flow. Our study also showed that this change of shape is an essential element explaining blood shear-thinning at high shear rates.
More details can be found in Lanotte et al., PNAS, 113, 2016.