%A Winkler,Mathias
%A Gjennestad,Magnus Aa.
%A Bedeaux,Dick
%A Kjelstrup,Signe
%A Cabriolu,Raffaela
%A Hansen,Alex
%D 2020
%J Frontiers in Physics
%C
%F
%G English
%K Non-equilibrium thermodynamics,Immiscible Two-Phase-Flow,Porous media,network model,fluctuations,Onsager reciprocal relations (ORR),time-correlation functions
%Q
%R 10.3389/fphy.2020.00060
%W
%L
%N 60
%M
%P
%7
%8 2020-April-03
%9 Original Research
%#
%! Onsager-Symmetry in Mesoscopic Systems
%*
%<
%T Onsager-Symmetry Obeyed in Athermal Mesoscopic Systems: Two-Phase Flow in Porous Media
%U https://www.frontiersin.org/article/10.3389/fphy.2020.00060
%V 8
%0 JOURNAL ARTICLE
%@ 2296-424X
%X We compute the fluid flow time correlation functions of incompressible, immiscible two-phase flow in porous media using a 2D network model. Given a properly chosen representative elementary volume, the flow rate distributions are Gaussian, and the integrals of time correlation functions of the flows are found to converge to a finite value. The integrated cross-correlations become symmetric, obeying Onsager's reciprocal relations. These findings support the proposal of a non-equilibrium thermodynamic description for two-phase flow in porous media.