Boundary Element Analysis on the Fluid-Dynamic Interaction between a Singly Flagellated Bacterium and a Free Surface

Abstract

Bacterial motion near a free surface was numerically investigated by use of the boundary element method. The fluid flow around a bacterial cell is approximated as a creeping flow. Boundary conditions on the free surface were satisfied by the basic solution for a half space that provides free shear stresses. The swimming speed and the rotational rate were calculated for a bacterial model with a single flagellum. The motion near a free surface was found to be quite different from the motion near a rigid surface which had been previously analyzed.