Synergetic Fluid Mixing from Viscous Fingering and Alternating Injection

We study mixing of two fluids of different viscosity in a microfluidic channel or porous medium. We show that the synergetic action of alternating injection and viscous fingering leads to a dramatic increase in mixing efficiency at high Péclet numbers. Based on observations from high-resolution simu...

Full description

Bibliographic Details
Main Authors: Jha, Birendra, Cueto-Felgueroso, Luis, Juanes, Ruben
Other Authors: Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Format: Article
Language:en_US
Published: American Physical Society 2014
Online Access:http://hdl.handle.net/1721.1/84969
https://orcid.org/0000-0003-3855-1441
https://orcid.org/0000-0002-7370-2332
https://orcid.org/0000-0003-3958-7382
Description
Summary:We study mixing of two fluids of different viscosity in a microfluidic channel or porous medium. We show that the synergetic action of alternating injection and viscous fingering leads to a dramatic increase in mixing efficiency at high Péclet numbers. Based on observations from high-resolution simulations, we develop a theoretical model of mixing efficiency that combines a hyperbolic mixing model of the channelized region ahead and a mixing-dissipation model of the pseudosteady region behind. Our macroscopic model quantitatively reproduces the evolution of the average degree of mixing along the flow direction and can be used as a design tool to optimize mixing from viscous fingering in a microfluidic channel.