Structural and dynamical characterization of Hele-Shaw viscous fingering

Area of Science:

• Fluid dynamics
• Interfacial phenomena
• Computational physics

Background:

• Viscous fingering is an instability in fluid flow within narrow gaps (Hele-Shaw geometry).
• It occurs when a less viscous fluid displaces a more viscous fluid, leading to complex interfacial patterns.
• Understanding this phenomenon is crucial for various applications, including oil recovery and microfluidics.

Purpose of the Study:

• To investigate the dynamics of spatially extended Hele-Shaw flow using a mesoscopic approach.
• To analyze the effect of surface tension and reactivity on viscous fingering.
• To characterize the onset, structure, and dynamics of the interface and mixing zone.

Main Methods:

• Lattice Boltzmann method (LBM) for mesoscopic simulation.
• Simulation of Hele-Shaw flow under varying surface tension and reactivity conditions.
• Analysis of dispersion relations, interface structure, and mixing zone growth.

Main Results:

• The study characterizes the onset of fingering instability and the resulting interface structures.
• It quantifies the growth of the mixing zone in Hele-Shaw systems.
• Reactive processes were shown to significantly influence the interfacial zone structure.

Conclusions:

• The lattice Boltzmann method provides a powerful tool for simulating complex fluid instabilities like viscous fingering.
• Surface tension and reactivity are key parameters controlling Hele-Shaw flow dynamics and interfacial morphology.
• Reactive processes can be harnessed to modify and control the mixing zone in such systems.