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arXiv · 1511.03912

Physical origin of nonequilibrium fluctuation-induced forces in fluids

T. R. Kirkpatrick·J. M. Ortiz de Zárate·J. V. Sengers
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Abstract

Long-range thermal fluctuations appear in fluids in nonequilibrium states leading to fluctuation-induced Casimir-like forces. Two distinct mechanisms have been identified for the origin of the long-range nonequilibrium fluctuations in fluids subjected to a temperature or concentration gradient. One is a coupling between the heat or mass-diffusion mode with a viscous mode in fluids subjected to a temperature or concentration gradient. Another one is the spatial inhomogeneity of thermal noise in the presence of a gradient. We show that in fluids fluctuation-induced forces arising from mode coupling are several orders of magnitude larger than those from inhomogeneous noise.

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T. R. Kirkpatrick, J. M. Ortiz de Zárate, J. V. Sengers. 2016-01-13. Physical origin of nonequilibrium fluctuation-induced forces in fluids. https://doi.org/10.1103/physreve.93.012148

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