Electrokinetic Control of Viscous Fingering

Area of Science:

• Physics
• Fluid Dynamics
• Electrochemistry

Background:

• The Saffman-Taylor problem describes viscous fingering in fluid flow.
• Electrolytes exhibit electrokinetic (EK) phenomena, influencing fluid behavior.
• Hele-Shaw cells and porous media are common experimental and natural systems for fluid flow studies.

Purpose of the Study:

• To develop a theory for interfacial stability of immiscible electrolytes.
• To investigate the coupled effects of pressure gradients and electric fields.
• To extend the Saffman-Taylor problem to include electrokinetic phenomena.

Main Methods:

• Mathematical modeling of "vector Laplacian growth."
• Analysis of interface movement driven by a vector-valued potential and generalized mobility tensor.
• Incorporation of electrokinetic phenomena into classical fluid dynamics.

Main Results:

• Viscous fingering in electrolytes can be controlled by electric fields.
• The injection ratio of electric current to flow rate is a critical parameter.
• Beyond a critical ratio, interfacial stability is independent of viscosity ratio and depends on flow-current direction.

Conclusions:

• Electric fields offer a novel method to control interfacial instabilities in electrolytes.
• The findings have implications for managing fluid flow in porous media.
• Potential applications include enhanced oil recovery and environmental remediation.