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Multiple-relaxation-time color-gradient lattice Boltzmann model for simulating two-phase flows with high density
Yan Ba1,2, Haihu Liu1, Qing Li3
1School of Energy and Power Engineering, Xi'an Jiaotong University, 28 West Xianning Road, Xi'an 710049, China.
Physical Review. E
|September 15, 2016
Summary
This study introduces a stable color-gradient lattice Boltzmann (LB) model for simulating two-phase flows. The model accurately captures complex phenomena like Rayleigh-Taylor instability and droplet splashing, even at high density ratios.
Area of Science:
- Computational fluid dynamics
- Multiphase flow simulation
- Numerical methods
Background:
- Simulating two-phase flows with high density ratios and Reynolds numbers presents significant computational challenges.
- Existing lattice Boltzmann (LB) models often struggle with stability and accuracy under these conditions.
Purpose of the Study:
- To develop and validate a novel color-gradient lattice Boltzmann (LB) model for accurate simulation of two-phase flows.
- To enhance model stability and ensure exact recovery of Navier-Stokes equations.
Main Methods:
- A multirelaxation-time (MRT) collision operator was employed for enhanced simulation stability.
- A source term derived from Chapman-Enskog analysis was integrated into the MRT LB equation.
- A simplified equilibrium density distribution function was utilized to streamline the source term.
Main Results:
- The model demonstrated high accuracy in simulating steady flows, including static droplets and layered channel flows, with density ratios up to 1000.
- Minimal spurious velocities and interfacial tension errors were observed in droplet simulations.
- Accurate predictions of interface dynamics were achieved for unsteady flows like Rayleigh-Taylor instability and droplet splashing.
Conclusions:
- The proposed color-gradient LB model offers a stable and accurate approach for simulating two-phase flows across a wide range of density ratios and Reynolds numbers.
- The model successfully reproduces key features of both steady and unsteady two-phase flow phenomena.
- This advancement provides a valuable tool for researchers studying complex fluid dynamics.
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