Transition point prediction in a multicomponent lattice Boltzmann model: Forcing scheme dependencies.

Area of Science:

• Computational physics
• Fluid dynamics
• Statistical mechanics

Background:

• Pseudopotential-based lattice Boltzmann models are standard for simulating multiphase flows.
• Multicomponent systems require tracking mass, momentum, and component-specific advection-diffusion.

Purpose of the Study:

• Investigate the impact of forcing schemes on advection-diffusion in multicomponent lattice Boltzmann models.
• Compare the standard and explicit forcing models for their diffusion characteristics.

Main Methods:

• Comparative analysis of two lattice Boltzmann model formulations: standard and explicit forcing.
• Derivation of a generalized expression for the miscible-immiscible transition point.
• Numerical simulations of static droplets and concentration waves for validation.

Main Results:

• The forcing scheme drastically alters diffusion characteristics.
• A potential function-dependent transition point from miscible to immiscible regimes is derived and shown to shift between models.
• Theoretical predictions for transition points and diffusion coefficients are validated.

Conclusions:

• The choice of forcing scheme is critical and influences diffusion behavior in multicomponent flows.
• Interfacial properties, including interfacial tension and contact angle modeling, are affected by diffusion characteristic shifts.
• The analysis is validated across various potential functions, demonstrating universality.