Growing Interface with Phase Separation and Spontaneous Convection during Hydrodynamically Stable Displacement

Area of Science:

• Fluid dynamics
• Interfacial phenomena
• Thermodynamics

Background:

• Fluid displacement is crucial in industrial and environmental applications like enhanced oil recovery and CO2 sequestration.
• Even in stable displacement, interfaces between fluids exhibit fluctuations influenced by miscibility.
• Understanding these fluctuations is key to controlling processes in porous media and Hele-Shaw cells.

Purpose of the Study:

• To analyze interfacial fluctuations in fluid displacement across fully miscible, partially miscible, and immiscible systems.
• To calculate scaling exponents (roughness α and growth β) for each system.
• To investigate the impact of miscibility on interface dynamics and develop predictive models.

Main Methods:

• Utilized Family-Vicsek scaling theory to analyze interfacial fluctuations.
• Calculated roughness exponent (α) and growth exponent (β) for different miscibility conditions.
• Compared fluctuation dynamics across the three thermodynamic systems.

Main Results:

• Partially miscible systems showed higher roughness (α) and growth (β) exponents compared to immiscible and fully miscible systems.
• Korteweg convection effects during phase separation were identified as the cause for increased exponents in partially miscible cases.
• Fluctuations across all systems collapsed onto a single curve when plotted with steady α and β values.

Conclusions:

• Interfacial fluctuation dynamics in fluid displacement are significantly influenced by miscibility.
• The findings enable accurate, scale-independent predictions of interface behavior in Hele-Shaw flows, regardless of miscibility.
• This research provides a unified framework for understanding and modeling interfacial dynamics in diverse fluid displacement scenarios.