Improved hybrid Allen-Cahn phase-field-based lattice Boltzmann method for incompressible two-phase flows

Area of Science:

• Computational Fluid Dynamics
• Phase-Field Modeling
• Numerical Analysis

Background:

• Phase-field models are crucial for simulating multiphase flows and interfaces.
• Traditional methods often suffer from numerical dispersion and coarsening, limiting accuracy.
• Lattice Boltzmann (LB) methods offer an efficient alternative for complex fluid dynamics.

Purpose of the Study:

• To develop an improved phase-field LB method for accurate simulation of fluid interfaces.
• To suppress numerical dispersion and eliminate coarsening phenomena in phase-field simulations.
• To explicitly calculate macroscopic order parameters for phase labeling.

Main Methods:

• Implementation of a hybrid Allen-Cahn equation (ACE) with a flexible weight.
• Utilizing two LB models to solve the hybrid ACE and Navier-Stokes equations.
• Chapman-Enskog analysis to validate the recovery of the hybrid ACE.

Main Results:

• The developed LB method successfully suppresses numerical dispersion and coarsening.
• Accurate simulation of various interfacial phenomena, including bubble dynamics and instabilities.
• Validation through five distinct numerical tests in 2D and 3D.

Conclusions:

• The improved phase-field LB method demonstrates superior performance in accuracy and stability.
• The flexible weight ACE effectively addresses limitations of traditional phase-field models.
• This method provides a robust tool for simulating complex multiphase flows.