A regularized lattice Boltzmann model with filter for multiphase flow with diffusion-dominated mass transfer considering two-film theory
A regularized lattice Boltzmann model with filter for multiphase flow with diffusion-dominated mass transfer considering two-film theory
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DOI：
10.1063/5.0172360
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发表时间：
2023-11
影响因子：
4.6
通讯作者：
Hanyang Mo;Yumei Yong;Wenqiang Chen;Jialin Dai;Chao Yang
中科院分区：
文献类型：
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作者：
Hanyang Mo;Yumei Yong;Wenqiang Chen;Jialin Dai;Chao Yang
在关键的工业过程中总是会遇到复杂的流动，用二膜理论考虑界面传质。相场格子玻尔兹曼方法 (PFLBM) 与修正的菲克定律传质对流扩散方程 (CDE) 相结合是预测两相流中体积浓度分布的实用方法。然而，当控制方程的弛豫时间接近 0.5（即扩散主导）时，浓度解会出现振荡，甚至在尖锐梯度附近发散。本文建立了一个考虑两相流和界面传质的集成 PFLBM 模型，采用新的滤波算法和碰撞算子，以扩展现有模型的更广泛范围，适用于具有极低扩散系数的两膜 CDE。首先，我们团队进一步发展了二阶形成的双膜传质模型，以满足两相界面浓度的高精度。然后，引入方向滤波算法和正则化有限差分（rLBM-FD）碰撞算子来提高数值稳定性并限制数值扩散。在两种情况下实现了四种常见的碰撞算子并进行了彻底的测试，以验证我们新模型的稳健性和准确性。总之，rLBM-FD 与标准非线性滤波器的组合达到了最高的鲁棒性、质量保守性和数值扩散限制。定向非线性滤波器的计算成本是所有微观可变滤波器中最低的，并且可以将鲁棒性提高两倍。宏观变量过滤不适合处理两膜平衡，因为质量损失和鲁棒性是不可接受的。
Complex flow, considering the interfacial mass transfer with the two-film theory, is always encountered in critical industrial processes. The phase-field lattice Boltzmann method (PFLBM) coupling with the revised Fick's law mass transfer convection–diffusion equation (CDE) is a practical approach to predict the bulk concentration distribution in two-phase flows. However, solutions of concentration have oscillations and even diverge near the sharp gradient when the relaxation time of governing equations is close to 0.5 (i.e., diffusion-dominated). In this paper, an integrated PFLBM model considering two-phase flow and interfacial mass transfer with a new filtering algorithm and collision operator was built to extend the wider range of the existing model for the two-film CDE with an extremely low diffusion coefficient. First, the two-film mass transfer model from our team was furthermore developed with the second-order formation to meet the high precision of concentration on two-phase interfaces. Then, directional filtering algorithms and regularized-finite-difference (rLBM-FD) collision operator were introduced to improve the numerical stability and limit the numerical diffusion. Four common collision operators were implemented and thoroughly tested in two cases to verify the robustness and accuracy of our new model. In conclusion, the combination of the rLBM-FD with standard non-linear filter reaches the highest robustness, mass-conservativeness, and limitation on numerical diffusion. The directional non-linear filter has the lowest computational cost of any microscopic variable filter and can increase the robustness by two times. Macro-variable filtering is not appropriate for treating the two-film equilibrium because the mass loss and robustness are unacceptable.