Wetting boundaries for a ternary high-density-ratio lattice Boltzmann method

Area of Science:

• Computational fluid dynamics
• Multicomponent fluid systems
• Interfacial phenomena

Background:

• Existing ternary free-energy lattice Boltzmann models with high density contrast lack detailed solid-wall interaction.
• Accurate simulation of wetting phenomena is essential for understanding complex fluid behaviors near surfaces.

Purpose of the Study:

• To extend a ternary free-energy lattice Boltzmann model by incorporating wetting boundary conditions at solid walls.
• To evaluate forcing and geometric schemes for implementing wetting in multicomponent lattice Boltzmann models.
• To validate the model's capability in simulating complex ternary fluid dynamics near solid boundaries.

Main Methods:

• Incorporation of wetting boundary conditions using forcing and geometric schemes.
• Optimization of implementations for ternary and higher-order multicomponent lattice Boltzmann models.
• Static and dynamic tests, including capillary filling dynamics and droplet train motion.

Main Results:

• Demonstrated the effectiveness of forcing and geometric schemes for wetting boundary implementations.
• Quantified dynamic contact angles and slip length dependence on equilibrium contact angles and interface types.
• Validated the model's accuracy through capillary filling and droplet motion simulations.

Conclusions:

• The enhanced ternary lattice Boltzmann model accurately simulates fluid dynamics with wetting boundaries.
• The model is capable of handling complex scenarios, such as drop impact on lubricated surfaces.
• Slip length is critically dependent on contact angles and interface characteristics.