A two-dimensional model for capillary flow of an asymmetric cell

The effect of asymmetry of cell shape on capillary flow of tightly fitting red blood cells is examined, using a two-dimensional model. The cell membrane is assumed to be perfectly flexible and inextensible, and to contain a viscous fluid interior. Lubrication theory is used to model the flow in the narrow gaps between the cell and the wall. It is shown that asymmetric cell shapes lead to tank-treading motion of the membrane, and also to a reduction in the driving pressure required to sustain a given cell velocity.