Dh. Matthiesen et al., Physical modeling of the effect of shearing on the concentration profile in a shear cell, J ELCHEM SO, 146(8), 1999, pp. 3087-3091
The effect of the action of shearing a column of molten gallium (Ga) doped
germanium (Ge) on the gallium concentration field in a shear cell segment w
as experimentally investigated using a physical model. A physical model is
an experimental system that is different from the system of interest but co
nnected by scaling relations. Water was used as the fluid in the physical m
odel in place of the molten germanium, and methylene blue dye was used as a
tracer in place of the gallium dopant to determine the extent of mixing. T
wo adjacent cylindrical fluid segments in a capillary of a shear cell were
studied with the physical model. These fluid segment dimensions were scaled
by a factor of seven for the physical model, since the kinematic viscosity
of water at 22.6 degrees C is seven times that of Ge at 950 degrees C. A s
mall amount of mixing between adjacent segments was measured due to the ini
tial fluid-fluid shear. The mass transfer between the top and bottom segmen
ts of the physical model during the fluid-fluid shear was found to be less
than 2% for all shear rates in the range 0.1-2.0 cm/s. The average mass tra
nsfer between adjacent segments due to the fluid-fluid shear in that sheari
ng range was 1.2%. (C) 1999 The Electrochemical Society. S0013-4651(98)10-0
77-0. All rights reserved.