Improved partially saturated method for the lattice Boltzmann pseudopotential multicomponent flows.

Area of Science:

• Computational fluid dynamics
• Multiphase flow modeling

Background:

• The lattice Boltzmann (LB) pseudopotential model simplifies complex flow simulations.
• Existing methods struggle with accurate wetting and contact angle modeling on curved boundaries, often causing mass leakage or inaccurate results due to staircase approximations.

Purpose of the Study:

• To extend the partially saturated method (PSM) for curved walls to the LB pseudopotential multicomponent model.
• To accurately model contact angles and improve wetting simulations on complex geometries.
• To address limitations of the bounce-back (BB) method and standard curved boundary conditions in LB models.

Main Methods:

• Adaptation of the partially saturated method (PSM) for LB pseudopotential multicomponent models.
• Implementation of wetting boundary conditions using mesoscopic interaction forces to mimic adhesive forces.
• Computation of pseudopotential interaction forces with eighth-order isotropy to prevent component condensation.
• Modification of the bounce-back (BB) method to handle curved walls more effectively.

Main Results:

• The improved PSM scheme demonstrates mass conservation.
• Nearly identical static contact angles were achieved on both flat and curved walls.
• Smoother movement of wetting droplets on curved and inclined walls was observed compared to the standard BB method.

Conclusions:

• The enhanced PSM is a mass-conservative and accurate method for simulating wetting phenomena on curved boundaries within LB pseudopotential models.
• This improved method overcomes the limitations of staircase approximations and mass leakage associated with traditional approaches.
• The developed technique shows significant promise for applications in modeling fluid flow in porous media and microfluidic devices.