Maxwell-Stefan-theory-based lattice Boltzmann model for diffusion in multicomponent mixtures

Area of Science:

• Multiphysics simulation
• Computational fluid dynamics
• Chemical engineering

Background:

• Diffusion in multicomponent mixtures is fundamental across science and engineering.
• Maxwell-Stefan (MS) theory is commonly used for mathematical modeling, assuming zero molar average velocity.
• Existing models may have limitations in computational efficiency or complexity.

Purpose of the Study:

• To develop a multiple-relaxation-time lattice Boltzmann (LB) model for mass diffusion in multicomponent mixtures.
• To demonstrate the recovery of MS continuum equations from the proposed LB model via Chapman-Enskog analysis.
• To enhance computational efficiency by utilizing simpler lattice structures.

Main Methods:

• Development of a multiple-relaxation-time lattice Boltzmann (LB) model.
• Chapman-Enskog analysis to validate the model against Maxwell-Stefan equations.
• Simulations on simplified lattice structures to reduce computational cost.

Main Results:

• The LB model successfully recovers the Maxwell-Stefan diffusion equations.
• Simulations show good agreement with existing research.
• The model captures phenomena such as reverse diffusion, osmotic diffusion, and diffusion barriers.

Conclusions:

• The proposed LB model offers an efficient and accurate method for simulating multicomponent diffusion.
• It preserves the advantages of single-component LB methods, including local collision implementation.
• The model provides a computationally less expensive alternative to complex kinetic-theory-based models.