Improved phase-field-based lattice Boltzmann model for liquid-gas flow with evaporation
1Xi'an Jiaotong University, State Key Laboratory for Strength and Vibration of Mechanical Structures, Shaanxi Key Laboratory of Environment and Control for Flight Vehicle, School of Aerospace Engineering, Xi'an 710049, China.
Physical Review. E
|October 21, 2025
Summary
This study introduces an improved phase-field lattice Boltzmann model for heat transfer in two-phase flow with evaporation. The model accurately simulates evaporation driven by vapor concentration, showing deviations of 12.2% and 52.1% when specific terms are omitted.
Area of Science:
- Computational fluid dynamics
- Thermodynamics
- Phase transitions
Background:
- Accurate simulation of two-phase flow with phase change is crucial for many engineering applications.
- Existing models may not fully capture the complex interplay of heat transfer and phase change phenomena like evaporation.
- The lattice Boltzmann method (LBM) offers a versatile framework for simulating complex fluid dynamics.
Purpose of the Study:
- To present an improved Allen-Cahn-based phase-field lattice Boltzmann model for simulating heat transfer in two-phase flow with evaporation.
- To couple vapor concentration and temperature fields using the Clausius-Clapeyron correlation.
- To validate the model's accuracy through numerical tests and investigate the impact of key model parameters.
Main Methods:
- Development of an enhanced phase-field lattice Boltzmann model using four distribution functions for velocity, phase, temperature, and vapor concentration.
- Coupling of vapor concentration and temperature fields via the Clausius-Clapeyron equation.
- Numerical simulations of one-dimensional (1D) Stefan flow and two/three-dimensional (2D/3D) droplet evaporation.
Main Results:
- The improved model demonstrates good agreement with theoretical expectations for evaporation phenomena.
- Comparison of evaporation driving modes (temperature vs. vapor concentration gradient) was performed.
- Investigated the influence of the volume expansion rate term (F_β) and the volume-specific heat gradient term (T_α), revealing significant deviations when T_α is omitted (52.1%) compared to F_β omission (12.2%).
Conclusions:
- The presented Allen-Cahn-based phase-field lattice Boltzmann model is a viable tool for simulating evaporation in two-phase flow with heat transfer.
- The vapor concentration at the interface is a key driver for vaporization, and its accurate modeling is essential.
- The model's sensitivity analysis highlights the importance of including specific terms like T_α for accurate predictions, especially in scenarios like 1D Stefan flow.
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