Abstract
In this work, the role of the hydrodynamic forces on a swimming microorganism near an air-liquid interface is studied. The lubrication theory is utilized to analyze hydrodynamic effects within the narrow gap between a flat interface and a small swimmer. By using an archetypal low-Reynolds-number swimming model called “squirmer,” we find that the magnitude of the vertical swimming velocity is on the order of , where is the ratio of the gap width to the swimmer's body size. The reduced swimming velocity near an interface can explain experimental observations of the aggregation of microorganisms near a liquid interface.
- Received 7 March 2013
DOI:https://doi.org/10.1103/PhysRevE.87.063010
©2013 American Physical Society