Journal Article

Slender axisymmetric Stokesian swimmers

Balmforth, N. J., Toppaladoddi, S.

2014

Overview

Slender-body theory is used to study axisymmetric swimmers propelled by motions of their surfaces. To leading order, the locomotion speed is given by an integral involving the fluid velocity at the surface of the slender body. Locomotion speeds are calculated for fixed-shape swimmers with prescribed fluid surface velocities and for impermeable swimmers driven by propagating surface waves. Next, the internal mechanics is considered, modelling the swimmer as a viscous fluid bounded by an elastic shell. Prescribed forces are exerted on the shell to drive both the internal and external fluid flow and the surface waves. The internal fluid mechanics is determined using lubrication theory. Locomotion speeds are calculated for transverse and longitudinal waves of surface deformation, and the efficiency of the motions is determined. Transverse surface waves are both weaker and less efficient at driving locomotion than longitudinal waves. The results indicate how estimates of swimming speed based on nearly spherical swimmers with low-amplitude surface waves can be adapted for slender swimmers with nonlinear surface deformations.

• Publisher: Cambridge University Press
• Subject: Biological and medical sciences / Cell physiology / Computational fluid dynamics / Deformation / Elastic shells / Fluid flow / Fluid mechanics / Forces (mechanics) / Fundamental and applied biological sciences. Psychology / Locomotion / Longitudinal waves / Lubrication / Modelling / Molecular and cellular biology / Motility and taxis / Surface velocity / Surface waves / Swimming / Viscous fluids / Wave propagation