Diverse Fingering Morphologies Driven by Reaction-Viscosity Coupling in a Hele-Shaw Cell

Viscous fingering occurs when low viscosity fluid pushes high viscosity fluid, and it has been studied extensively in relation to mixing processes and petroleum extraction. In addition, previous research has shown that instabilities also develop by gel formation near the interface of pressure-driven viscosity-matched fluids. In this talk, we will present a novel system where the effects of gel formation, viscosity differences, and non-Newtonian behavior on interfacial instability are observed in concert, a scenario with potential applicability to subterranean carbon sequestration, manufacturing, and biological processes. In this system, the characteristics of the instability and resulting fingering patterns are determined by the competition of the diffusion and reaction timescales associated with gel formation and the advection timescale that drives viscous fingering. By adjusting flow rates, reactant concentrations, and viscosities in a Hele-Shaw cell, these timescales are manipulated to reveal a range of interesting finger morphologies.