Seminar Abstract
September 3, 2003:
"Oscillations in Phase Separating Binary Fluids with Continuously
Ramped Temperature"
Professor Alexander Wagner
Department of Physics
North Dakota State University
We consider the demixing, under gravity, of a binary fluid mixture,
which is steadily driven into a two-phase region by slowly
ramping the temperature. We simulate this mixture using a
lattice Boltzmann method. This system exhibits two distinct
instabilities. The first arises because the over-saturation is largest
far from the meniscus resulting in a density inversion. This inversion
can lead to fluid flow. The second is due to the intrinsic spinodal
instability that will lead to phase-separation at large
over-saturations. In this regime, interesting oscillations can be found
where new domains are created, reducing the over-saturation after which
they fall out of the solution. More complex oscillatory regimes are
found where both instabilities are important.
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