Laboratory for
Applied Fluid Dynamics Northwestern University, Evanston, Illinois
Taylor-Couette flow is a classic case of an unstable flow. In this case,
the centrifugal instability manifests itself in the form of toriodal Taylor vortices
stacked like donuts in the annulus between a rotating inner cylinder and a fixed
outer cylinder. We are studying the effect of particles in the fluid on the stability
of the flow (particle laden Taylor-Couette flow). Experiments have been carried
out using 20 micron particles and the stability map obtained is shown in the figure
below. The critical Taylor number above which the flow is unstable is plotted
on the abscissa and the concentration of particles is plotted on the ordinate.
The map of the super-critical transition to wavy vortices is also shown. Theoretical
studies using linear stability analysis have also been carried out.
Stability map of particle
laden Taylor-Couette flow
blue - Taylor vortex flow; red - Wavy vortex flow
"Hydrodynamic stability
of a suspension in Taylor Couette flow," Ali, M, Mitra, D, Schwille,
J.A. and Lueptow, RM, to appear in Physics of Fluids, 2002.
Spatio-temporal character
of nonwavy and wavy Taylor Couette flow," Wereley, ST, and Lueptow, RM, Journal
of Fluid Mechanics, 364:59-80, 1998.
"Hydrodynamic stability
of flow between rotating porous cylinders with radial and axial flow," Johnson,
EC, and Lueptow, RM, Physics of Fluids, 9:3687-3696, 1997.
"Hydrodynamic stability
of viscous flow between rotating porous cylinders with radial flow," Min,
K and Lueptow, RM, Physics of Fluids, 6:144-151, 1994.
