title: Diffusive transport by thermal velocity fluctuations.
abstract: We study the contribution of advection by thermal velocity fluctuations to the effective diffusion coefficient in a mixture of two identical fluids. We find good agreement between a simple fluctuating hydrodynamics theory and particle and finite-volume simulations. The enhancement of the diffusive transport depends on the system size L and grows as ln(L/L₀) in quasi-two-dimensional systems, while in three dimensions it scales as L₀⁻¹ - L⁻¹, where L₀ is a reference length. Our results demonstrate that fluctuations play an important role in the hydrodynamics of small-scale systems.
authors.affiliation: Courant Institute of Mathematical Sciences, New York University, New York, New York 10012, USA. donev@courant.nyu.edu
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Donev
authors.forename: John B
authors.initials: JB
authors.lastname: Bell
authors.forename: Anton
authors.initials: A
authors.lastname: de la Fuente
authors.forename: Alejandro L
authors.initials: AL
authors.lastname: Garcia