Structure of a sheared soft-disk fluid from a nonequilibrium potential.

Area of Science:

• Soft-disk fluid dynamics
• Computational physics
• Statistical mechanics

Background:

• Studying the structural distortion of fluids under shear flow is crucial for understanding their behavior.
• Nonequilibrium molecular dynamics (NEMD) and equilibrium Monte Carlo (MC) simulations are key computational tools.

Purpose of the Study:

• To investigate the structural changes in a soft-disk fluid under two-dimensional plane Couette flow.
• To validate the use of equilibrium simulations with a nonequilibrium potential to replicate nonequilibrium fluid structures.

Main Methods:

• Nonequilibrium molecular dynamics (NEMD) simulations were performed.
• Equilibrium Monte Carlo (MC) simulations utilized a derived nonequilibrium potential.
• An extended iterative predictor-corrector method was employed to extract the nonequilibrium potential.

Main Results:

• Excellent agreement was observed between NEMD and MC simulations for structural properties.
• The pressure tensor calculations also showed good concordance between the two simulation methods.
• The study demonstrated that nonequilibrium liquid structure can be accurately reproduced using equilibrium simulations.

Conclusions:

• The findings confirm that equilibrium simulations with a carefully chosen nonequilibrium potential can accurately model nonequilibrium fluid structures.
• This approach provides a reliable method for generating "experimental" data to guide theoretical developments in fluid dynamics.
• The validated method offers a pathway for testing and refining theoretical models of nonequilibrium systems.