Finite-size effects on Soret-induced nonequilibrium concentration fluctuations in binary liquids

Abstract

We consider a horizontal binary-liquid layer that is subjected to a stationary temperature gradient while still being maintained in a stable quiescent state without any convection. In such a thermal nonequilibrium state the Soret effect induces concentration fluctuations. In the present paper we show how the finite height of the liquid layer will affect the long-range nature of these nonequilibrium concentration fluctuations at very small wave numbers. Estimates of the wave numbers where light-scattering or shadowgraph experiments will be affected by finite-size effects are presented.