Wetting boundary scheme implemented in three-dimensional phase-field lattice Boltzmann model with large density...

Area of Science:

• Computational Fluid Dynamics
• Multiphase Flow Simulation
• Phase-Field Modeling

Background:

• Simulating gas-liquid-solid systems with large density ratios presents challenges, particularly in accurately handling three-dimensional curved solid surfaces.
• Existing phase-field lattice Boltzmann (LB) methods struggle with systematic and precise treatment of complex geometries.

Purpose of the Study:

• To develop and validate a novel wetting boundary scheme for the phase-field LB method.
• To enable accurate simulation of multiphase flows with high density ratios (up to 1000) involving complex solid surfaces.
• To explore new wetting dynamics phenomena.

Main Methods:

• Developed a phase-field LB model capable of handling density ratios up to 1000.
• Employed a free-energy approach to identify solid boundary locations and normal vectors.
• Implemented spatially dependent interpolation schemes to impose wetting conditions.

Main Results:

• Validated the proposed method using benchmark cases: droplet on a sphere, capillary rise in tubes, and droplet on conical fibers.
• Demonstrated high accuracy in simulating both static and dynamic wetting processes.
• Successfully handled arbitrarily complex three-dimensional curved surfaces.
• Observed two novel power-law behaviors in droplet dynamics on conical fibers.

Conclusions:

• The proposed wetting boundary scheme effectively addresses limitations in simulating gas-liquid-solid flows with large density ratios and complex geometries.
• The method achieves high accuracy and robustness for diverse wetting scenarios.
• The model shows potential for discovering new phenomena in wetting dynamics.