Together with Vincent Langlois, Thomas Kiørboe, Tomas Bohr, and
Andy Visser I have worked on two simple models of the flow generated
by a self-propelled flagellate: a sphere propelled by a cylindrical
flagellum and one propelled by an external point force. We have used
the models to examine the role of advection in enhancing feeding rates
in different situations. The models showed that a more correct
representation of the flow field than that predicted by a naive
sinking sphere model leads to substantially higher clearance rates for
interception-feeding flagellates since the streamlines are drawn closer
to the cell surface. We also found that a short flagellum is favourable for
interception feeding, but at the cost of an increase in the drag on
the body of the swimming unicell. We finally demonstrated that prey
motility significantly enhances prey encounter rates in
interception-feeding flagellates and is, in fact, often much more
important for food acquisition than the feeding current.