Measurements of translational and rotational velocities of a sphere in Stokes flow.
by
Nicolas Lecoq
UMR 6634 CNRS Université de Rouen, 76821 Mont Saint Aignan, France
Coauthors: R. Anthore, M.L Ekiel-Jezewska, F. Feuillebois

The motion of a sphere in a viscous liquid is measured with an interferometric technique together with a video system. The laser interferometric technique is used to measure the translational velocity in the vertical direction (direction of gravity) with an excellent precision. The laser beam reflected by the sphere in motion as a cone of light is also used as the input to a system controlling the horizontal motion of the sphere. A video system with associated image analysis software is used to measure the rotational velocity of the sphere together with the translational one. These combined techniques are demonstrated to study the relative motion of two nearby rough particles which come into apparent contact in a surrounding Stokes flow. Hydrodynamic interactions and contact forces combine to give rolling and rolling plus slip regimes.

Date received: February 4, 1999

Copyright © 1999 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cacp-34.