Seminar Abstract
March 29, 2004
"The Hydrodynamics of Complex Fluids:
From Cholesteric Liquid Crystals to Superhydrophobic Substrates"
Professor Julia M. Yeomans
Department of Theoretical Physics
University of Oxford
We use the lattice Boltzmann algorithm as a tool to
investigate the hydrodynamic properties of complex fluids.
As a first example we consider a strongly non-Newtonian fluid,
cholesteric liquid crystals. When these are forced along a direction
parallel to the helical axis the apparent viscosity increases by
several orders of magnitude. We explain some puzzles in the Helfrich
theory of this effect.
We then investigate the dynamics of micron-scale droplets spreading on
chemically and topologically patterned substrates. For a substrate
with lyophobic and lyophilic stripes of the same dimensions as the
drop the final droplet shape is determined by the dynamic evolution of
the fluid. For a substrate patterned with posts the substrate becomes
superhydrophobic -- like the back of the Nambian desert beetle.
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