Wall Effect on a Sphere in a Rotating Viscous Fluid

Experiments were carried out to study the wall effect on the slow motion of a sphere along the axis of a rotating cylinder of viscous liquid. In comparison to Stokes flow of a sphere along the axis of a cylinder of viscous liquid for which it has been well established by previous researchers that the wall effect is a function of the geometry of the sphere and cylinder only, the wall effect on the sphere motion when the cylinder is rotated is a function of rotational speed and kinematic viscosity of the liquid as well as the geometry of the sphere and cylinder. For values of the Taylor number less than unity, rotation may either increase or decrease the wall effect depending upon the magnitude of the rotational speed and the viscosity and density of the liquid.