Lattice Boltzmann Solver for Multiphase Flows: Application to High Weber and Reynolds Numbers
Seyed Ali Hosseini1,2, Hesameddin Safari1, Dominique Thevenin1
1Laboratory of Fluid Dynamics and Technical Flows, University of Magdeburg "Otto von Guericke", D-39106 Magdeburg, Germany.
Entropy (Basel, Switzerland)
|February 12, 2021
Summary
A new algorithm using the lattice Boltzmann method models multiphase flows at high Reynolds/Weber numbers. This method accurately simulates complex phenomena like droplet splashing, advancing fluid dynamics research.
Area of Science:
- Computational fluid dynamics
- Multiphase flow modeling
- Numerical methods
Background:
- Lattice Boltzmann Method (LBM) is widely used for fluid simulations.
- Modeling multiphase flows at high Reynolds/Weber numbers remains challenging.
- Existing LBM formulations struggle with large density/viscosity ratios.
Purpose of the Study:
- Develop and validate an LBM algorithm for high Reynolds/Weber number multiphase flows.
- Extend LBM capabilities to accurately simulate complex interfacial phenomena.
- Address limitations in modeling large density and viscosity ratios.
Main Methods:
- Employed a decoupled phase-field formulation (conservative Allen-Cahn equation).
- Utilized a cumulant-based collision operator within a low-Mach pressure-based flow solver.
- Validated the algorithm with Rayleigh-Taylor instability and droplet impact simulations.
Main Results:
- The algorithm accurately captured flow dynamics in 2D and 3D test cases.
- Simulations of droplet splashing on a liquid sheet showed excellent agreement with reference data.
- Successfully modeled water/air droplet splashing with high density (1000:1) and viscosity (15:1) ratios at We=8000, Re=1000.
Conclusions:
- The developed LBM algorithm effectively simulates high Reynolds/Weber number multiphase flows.
- The method accurately reproduces complex phenomena like fingering instabilities and breakup during droplet splashing.
- This work provides a robust tool for advanced multiphase flow research.
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