Hydrodynamics of self-propulsion near a boundary: predictions and accuracy of far-field approximations

摘要

The swimming trajectories of self-propelled organisms or synthetic devices ina viscous fluid can be altered by hydrodynamic interactions with nearbyboundaries. We explore a multipole description of swimming bodies and provide ageneral framework for studying the fluid-mediated modifications to swimmingtrajectories. The validity of the far-field description is probed for aselection of model swimmers of varying geometry and propulsive activity bycomparison with full numerical simulations. The reduced model is then used todeliver simple but accurate predictions of hydrodynamically generated wallattraction and pitching dynamics, and may help to explain a number ofexperimental results.