Department of Physics


Department of Physics Apple - Gravity

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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.