Abstract
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.
Highlights
Athermal fluctuations occur in a number of phenomena in nature and are important to biology, chemistry, and physics [1,2,3]
The fluctuations appear on a mesoscopic scale much larger than the molecular scale of statistical thermodynamics, yet the mesoscopic scale that is defined by the pore sizes of the medium is very small compared to the overall system
We proceed to give the structure of the time correlation functions for the representative elementary volume (REV)
Summary
Athermal fluctuations occur in a number of phenomena in nature and are important to biology, chemistry, and physics [1,2,3]. The transport of the two immiscible fluids through a twodimensional porous medium is represented by a dynamical pore network model [18, 22] This model has been in development for over two decades and has a record of explaining experimental and theoretical results in steady and transient two-phase flow in porous media [11,12,13, 18, 20, 22,23,24,25]. It has been tested that a different link radii configuration drawn from the same uniform distribution does not change the steady flow averages nor the appearance of the time correlation functions computed in this study. Sw is the volume fraction of the wetting phase of the total pore volume in the network
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
