章诗婷, 肖鸿威, 周锦翔, 等. 广义守恒相场简化多相流格子Boltzmann方法[J]. 空气动力学学报, 2022, 40(3): 75−86. doi: 10.7638/kqdlxxb-2021.0327
引用本文: 章诗婷, 肖鸿威, 周锦翔, 等. 广义守恒相场简化多相流格子Boltzmann方法[J]. 空气动力学学报, 2022, 40(3): 75−86. doi: 10.7638/kqdlxxb-2021.0327
ZHANG S T, XIAO H W, ZHOU J X, et al. Generalized conservative phase-field model based lattice Boltzmann method for multiphase flows[J]. Acta Aerodynamica Sinica, 2022, 40(3): 75−86. doi: 10.7638/kqdlxxb-2021.0327
Citation: ZHANG S T, XIAO H W, ZHOU J X, et al. Generalized conservative phase-field model based lattice Boltzmann method for multiphase flows[J]. Acta Aerodynamica Sinica, 2022, 40(3): 75−86. doi: 10.7638/kqdlxxb-2021.0327

广义守恒相场简化多相流格子Boltzmann方法

Generalized conservative phase-field model based lattice Boltzmann method for multiphase flows

  • 摘要: 针对不可压缩、非混溶的复杂多相流问题,提出一种广义守恒相场简化多相流格子Boltzmann方法。此方法运用早前发展的简化多相流格子Boltzmann方法(simplified multiphase lattice Boltzmann method,SMLBM),通过采用带有拉格朗日算子的广义守恒相场方程来控制界面的演化并确保每个相的体积和总质量守恒。此外,在单松弛格子Boltzmann方法框架内,SMLBM是通过预测-校正策略来模拟流体系统和跟踪界面演化,其计算过程中仅需要考虑平衡态分布函数的演化,并且平衡态分布函数可直接从宏观量计算得到,因而具有良好的稳定性、高计算效率和边界条件易于实施的优点。本方法继承了SMLBM的优势,能够解决由不同流体组分之间的大密度比和大黏度比引起的界面处大压力梯度问题。为了验证本方法的稳定性和准确性,模拟了包括拉普拉斯定律、液滴透镜、三相泊肃叶流以及复合液滴铺展在内的四个多相流算例。结果表明,本方法能有效地模拟密度比达1200和黏度比达500的复杂界面算例。

     

    Abstract: A generalized conservative phase-field simplified lattice Boltzmann method is proposed, which is suitable for incompressible and immiscible complex multiphase flow problems. This method extends our earlier simplified multiphase lattice Boltzmann method (SMLBM) by using a generalized conservative equation with Lagrange multiplier to control the evolution of the interface and ensures the conservations of the volume and total mass of each phase. Moreover, the SMLBM mimics the fluid systems and interface dynamics with a predictor-corrector scheme in the frame of single-relaxation lattice Boltzmann method by considering only the evolution of equilibrium distribution function, which can be directly calculated from the macroscopic variables. Therefore, this method inherits the advantages of good stability, high computational efficiency, and easy implementation of boundary conditions of the SMLBM, which is utilized for solving the interface problems with large gradients induced by large density ratios and large viscosity ratios between different fluid components. To validate the present method, four multiphase flow examples including Laplace law, spreading of a liquid lens, Poiseuille flow with three phases and spreading of a compound droplet are simulated. The results show that this method can effectively simulate complex interface multiphase flows with the density ratio of 1200 and the viscosity ratio of 500.

     

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