Hydrodynamic behavior of the pseudopotential lattice Boltzmann method for interfacial flows

Area of Science:

• Fluid dynamics
• Computational physics
• Mesoscale simulations

Background:

• The lattice Boltzmann method (LBM) is widely used for simulating multiphase flows with interfaces.
• LBM's mesoscale nature and Chapman-Enskog analysis assumptions are challenged near interfaces due to spurious non-hydrodynamical contributions.
• Quantitative hydrodynamic checks are necessary for LBM pseudopotential models in interface-heavy scenarios.

Purpose of the Study:

• To analyze the hydrodynamic behavior of LBM pseudopotential models.
• To investigate the Plateau-Rayleigh instability in liquid ligament breakup simulations.
• To assess the impact of different LBM collision operators on simulation accuracy.

Main Methods:

• Simulations of liquid ligament breakup using LBM pseudopotential models.
• Analysis performed in the "sharp interface" limit by fixing interface thickness and varying ligament radius.
• Evaluation of various LBM collision operators.

Main Results:

• Different distributions of spurious currents along the interface significantly affect simulation results.
• The outcome of pseudopotential model simulations is sensitive to the choice of LBM collision operator.
• The study highlights the need for fine-tuning pseudopotential models for time-dependent interface problems.

Conclusions:

• LBM pseudopotential models require careful calibration, especially for time-dependent multiphase flow simulations.
• Understanding and mitigating spurious currents is crucial for accurate interface simulations.
• The findings offer valuable insights for applying LBM pseudopotential models to liquid jet hydrodynamics.