Flow of yield stress fluid in a percolating network

Area of Science:

• Fluid Dynamics
• Porous Media Physics
• Statistical Mechanics

Background:

• Bingham yield stress fluids exhibit complex flow behavior.
• Pore network models are crucial for understanding fluid transport in porous media.
• Percolation theory describes the formation of connected pathways in disordered systems.

Purpose of the Study:

• To investigate the flow regimes of Bingham fluids in a pore network with blocked throats.
• To analyze the impact of pore size distribution and blockage on fluid flow.
• To characterize flow behavior above and at the percolation threshold.

Main Methods:

• Simulated fluid flow of a Bingham fluid in a 2D pore network model.
• Utilized a uniform distribution for pore throat radii.
• Blocked a fraction of the largest pore radii to study percolation effects.
• Analyzed flow curves, critical pressure drop, and permeability.

Main Results:

• Identified two distinct flow regimes: deterministic above the percolation threshold and non-self-averaging at the threshold.
• Quantified subleading fluctuations in flow observables above the percolation threshold.
• Demonstrated that at the percolation threshold, flow scaling is governed by the critical backbone.

Conclusions:

• The flow of Bingham fluids in disordered pore networks exhibits critical phenomena related to percolation.
• Understanding these regimes is vital for applications involving yield stress fluids in porous materials.
• The critical backbone dictates flow behavior at the percolation threshold, irrespective of specific pore geometry realizations.