Gravity effects on Soret-induced non-equilibrium fluctuations in ternary mixtures
Martínez Pancorbo, P
Ortiz de Zárate, JM
The European Physical Journal E
© The Author(s) 2017. This article is published with open access at Springerlink.com This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
We discuss the gravity effects on the dynamics of composition fluctuations in a ternary mixture around the non-equilibrium quiescent state induced by thermodiffusion when subjected to a stationary temperature gradient. We found that the autocorrelation matrix of concentration fluctuations can be expressed as the sum of two exponentially decaying concentration modes. Without accounting for confinement, we obtained exact analytical expressions for the two decay rates which, as a consequence of gravity, display a wave-number-dependent mixing. The stability of the quiescent solution is also examined, as a function of the two solutal Rayleigh numbers used to express the decay rates. After having discussed the dynamics of the two concentration modes, we calculate the corresponding amplitudes. Consequences for optical experiments are discussed.
We kindly acknowledge support from the SCCO Space Project (a joint venture of ESA and the Chinese Space Agency). The research at UCM was partly funded by the Spanish State Secretary of Research under Grant No. FIS2014-58950-C2-2-P. FC acknowledges financial support from the Centre National d’Etudes Spatiales of France.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.