Translational viscous drags of an ellipsoid straddling an interface between two fluids

Phys Rev E. 2016 Jul;94(1-1):012602. doi: 10.1103/PhysRevE.94.012602. Epub 2016 Jul 5.

Abstract

We study the dynamics of individual polystyrene ellipsoids of different aspect ratios trapped at the air-water interface. Using particle tracking and in situ vertical scanning interferometry techniques we are able to measure translational drags and the protrusion in air of the ellipsoids. We report that translational drags on the ellipsoid are unexpectedly enhanced: despite the fact that a noticeable part of the ellipsoid is in air, drags are found larger than the bulk one in water.