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| 2001-2002 Fluids Seminar Page |
Department of Aerospace Engineering & Mechanics
University of Minnesota
Abstract-
Topological transitions in mixtures of glycerin/water solution and silicone oil
are investigated with the goal of developing generalized numerical transition
models for practical applications. Refractive index matching and laser induced
fluorescence are employed to obtain clear images of the interface and interior
within each flow. Planar velocity fields are obtained by particle image
velocimetry. Two geometries are examined: natural and periodically forced
jets flowing into and breaking up in an ambient, and drops impacting and
eventually coalescing at a quiescent interface. The effects of fluid viscosity
ratio, Reynolds number, and Strouhal number on the flow dynamics will be
discussed. Also, some of the experimental results will be compared with the
results of numerical simulations using the 'partial miscibility regularization'
of Lowengrub and Truskinovsky. In this approach, a concentration field c is
introduced, and sharp interfaces are replaced by narrow transition layers in
c. The concentration equation is a fourth order, nonlinear diffusion equation
of the Cahn-Hilliard type which models a partial miscibility between the
fluids.
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