title: Non-equilibrium fluctuations induced by the Soret effect in a ternary mixture.
abstract: We present, based on fluctuating hydrodynamics, the theory of concentration fluctuations in a ternary mixture subjected to a stationary temperature gradient, so that composition gradients are present due to thermal diffusion (Soret effect). We neglect gravity and confinement (boundary conditions) but consider a completely generic diffusion matrix, including cross-diffusion effects. We find, as in the case of binary mixtures, an important non-equilibrium enhancement of the concentration fluctuations, which is proportional to the square of the gradient and inversely proportional to the fourth power of the fluctuations wave number, q(-4). The results of this paper are expected to be asymptotically correct for fluctuations of large q, while for shorter q gravity and confinement effects need to be incorporated. Comparison with previous work in the topic is included.
authors.affiliation: Departamento de Física Aplicada I, Universidad Complutense, Plaza de las Ciencias, 1, 28040, Madrid, Spain, jmortizz@fis.ucm.es.
authors.forename: José M
authors.initials: JM
authors.lastname: Ortiz de Zárate
authors.forename: Cédric
authors.initials: C
authors.lastname: Giraudet
authors.forename: Henri
authors.initials: H
authors.lastname: Bataller
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Croccolo