Rp. Chhabra et al., Drag on spheres in rolling motion in inclined smooth tubes filled with incompressible liquids, POWD TECH, 113(1-2), 2000, pp. 114-118
The fluid-dynamic resistance to spheres rolling down inclined smooth wall t
ubes filled with Newtonian liquids has been investigated experimentally. Nu
merous spheres made of glass and steel have been used in conjunction with f
our smooth walled glass tubes of different diameters. In order to cover a w
ide range of sphere Reynolds number, numerous aqueous solutions of glycerol
and glucose syrup were used to obtain Liquids of different viscosities. Al
together, the present work encompasses angles of inclination from 3 degrees
to 30 degrees, sphere-to-tube diameter ratios from 0.114 to 0.58, and the
sphere Reynolds number from 10(-6) to 3000. The drag on a sphere in rolling
motion is always greater than that on a freely falling sphere under all ki
nematic conditions, although as the value of Reynolds number increases the
divergence between the two values diminishes. (C) 2000 Elsevier Science S.A
. All rights reserved.