Roughness and growth in a continuous fluid invasion model.

Area of Science:

• Physics
• Fluid Dynamics
• Materials Science

Background:

• The continuous fluid invasion model describes interface growth under quasistatic pressure, leading to instabilities.
• Existing models do not fully account for the complex interplay of physical mechanisms governing interface behavior.

Purpose of the Study:

• To investigate interface characteristics in a continuous fluid invasion model.
• To propose and analyze a variant of the model that alters the order of instability treatment.
• To explain discrepancies in experimental data for the roughness exponent.

Main Methods:

• Simulation of a modified continuous fluid invasion model.
• Analysis of interface growth dynamics under applied quasistatic pressure.
• Examination of the roughness exponent's dependence on wetting properties.

Main Results:

• The modified model predicts a third, intermediate regime for the roughness exponent.
• This regime exhibits a gradual increase in the roughness exponent.
• The growth exponent was observed to be near zero due to an initially rough interface.

Conclusions:

• The proposed model variant offers a potential explanation for scattered experimental roughness exponent data.
• Altering the order of instability treatment reveals new physical insights.
• The study advances the understanding of interface dynamics in fluid invasion processes.