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Updated: May 18, 2026
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Multicomponent interparticle-potential lattice Boltzmann model for fluids with large viscosity ratios.
Mark L Porter1, E T Coon, Q Kang
1Earth Systems Observations, EES-14, Los Alamos National Laboratory, Los Alamos, New Mexico, USA. porterma@lanl.gov
Summary
This study introduces an improved lattice Boltzmann model for simulating fluid dynamics. The new model accurately handles high viscosity ratios and reduces numerical errors, outperforming the original Shan and Chen model.
Area of Science:
- Computational Fluid Dynamics
- Multiphase Flow Simulation
- Lattice Boltzmann Methods
Background:
- The Shan and Chen (SC) model is a common approach for simulating multiphase flows using lattice Boltzmann methods.
- However, the SC model exhibits limitations, including viscosity-dependent equilibrium densities and difficulties in simulating high kinematic viscosity ratios.
Purpose of the Study:
- To develop and validate an improved multicomponent interparticle-potential lattice Boltzmann model.
- To overcome the limitations of the SC model, particularly regarding viscosity independence and simulation of high viscosity ratios.
Main Methods:
- Incorporation of external forces directly into the discrete Boltzmann equation.
- Derivation and use of a momentum-conserving effective velocity.
- Application of higher-order isotropy in calculating fluid-fluid interaction forces to minimize spurious currents.
Main Results:
- The improved model yields viscosity-independent equilibrium densities, unlike the SC model.
- Stable simulation of bubbles with kinematic viscosity ratios exceeding 1000, a significant improvement over the SC model's limit of approximately 10.
- Accurate prediction of surface tension via Laplace's law across various kinematic viscosities and ratios.
- Successful simulation of layered cocurrent flow, preserving interface continuity and accurately predicting relative permeability for a wide range of viscosity ratios.
Conclusions:
- The enhanced lattice Boltzmann model offers superior accuracy and stability for simulating multiphase flows, especially those with large viscosity contrasts.
- The model's ability to handle high viscosity ratios and reduce numerical artifacts makes it a valuable tool for complex fluid dynamics problems.
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