Interactions between two close spheres in Stokes flow
We investigate if two close spheres in a fluid flow at low-Reynolds-number can touch each other and interact mechanically. We outline how this problem relates to microhydrodynamics of suspensions. We measure the translational and rotational motion of a sphere, which settles in a silicon oil onto another, fixed sphere of the same size. We use simultaneously a video system and a laser interferometer coupled with encoders. We calculate the motion, assuming that the particles come into contact and that the mechanical interactions superpose with the gravitational and hydrodynamic forces. The experiment confirms the model and determines its parameters.
KeywordsHydrodynamic Interaction Stoke Flow Laser Interferometer Friction Matrix Static Friction Coefficient
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- Cichocki, B., Felderhof, B.U. & Schmitz, R. 1988 Hydrodynamic interactions between two spherical particles. PCH Physico Chem. Hydrodyn.10, 383–403.Google Scholar
- Felderhof, B.U. 1990 Hydrodynamics of suspensions. In Fundamental Problems in Statistical Mechanics VII (ed. H. van Beijeren), pp. 225–254. North-Holland.Google Scholar
- Wajnryb, E. & Dahler, J.S. 1997 The Newtonian viscosity of a moderately dense suspension. In Adv. Chem. Phys., Vol. 102 (ed. I. Prigogine & S.A. Rice), pp. 193–313. Wiley.Google Scholar