Particle-based mesoscopic model for phase separation in a binary fluid mixture

Area of Science:

• Computational physics
• Fluid dynamics
• Materials science

Background:

• Phase separation in binary fluids is crucial for material properties.
• Existing simulation methods may lack accuracy in capturing nonideal fluid behavior.

Purpose of the Study:

• To develop and validate a mesoscopic simulation model for 3D binary fluid phase separation.
• To incorporate nonideal fluid interactions and thermodynamic consistency into particle-based simulations.

Main Methods:

• Augmenting the multiparticle collision dynamics (MPCD) algorithm.
• Incorporating excluded-volume interactions and stochastic collisions based on local fluid properties.
• Thermodynamic consistency validated through pressure calculations (simulation and analytical).

Main Results:

• The developed model accurately describes the nonideal equation of state for binary fluid mixtures.
• Phase diagrams were generated, identifying parameters leading to phase separation.
• Interfacial width and phase growth dynamics were consistent with existing literature.

Conclusions:

• The augmented MPCD model provides a thermodynamically consistent and accurate approach for simulating binary fluid phase separation.
• This model is suitable for exploring a wide range of parameters and conditions relevant to fluid behavior.