Axisymmetric lattice Boltzmann model for multiphase flows with large density ratio

Content Provider	Semantic Scholar
Author	Liang Li, Yang Chen, Jiangxing Xu, Jiangrong
Copyright Year	2018
Abstract	In this paper, a novel lattice Boltzmann (LB) model based on the AllenCahn phase-field theory is proposed for simulating axisymmetric multiphase flows. The most striking feature of the model is that it enables to handle multiphase flows with large density ratio, which are unavailable in all previous axisymmetric LB models. The present model utilizes two LB evolution equations, one of which is used to solve fluid interface, and another is adopted to solve hydrodynamic properties. To simulate axisymmetric multiphase flows effectively, the appropriate source term and equilibrium distribution function are introduced into the LB equation for interface tracking, and simultaneously, a simple and efficient forcing distribution function is also delicately designed in the LB equation for hydrodynamic properties. Unlike many existing LB models, the source and forcing terms of the model arising from the axisymmetric effect include no additional gradients, and consequently, the present model contains only one non-local phase field variable, which in ∗Corresponding author. Email address: lianghongstefanie@163.com (Hong Liang); jrxu@hdu.edu.cn (Jiangrong Xu) Preprint submitted to Elsevier October 23, 2018 this regard is much simpler. In addition, to enhance the model’s numerical stability, an advanced multiple-relaxation-time (MRT) model is also applied for the collision operator. We further conducted the Chapman-Enskog analysis to demonstrate the consistencies of our present MRT-LB model with the axisymmetric Allen-Cahn equation and hydrodynamic equations. A series of numerical examples, including static droplet, oscillation of a viscous droplet, breakup of a liquid thread, and bubble rising in a continuous phase, are used to test the performance of the proposed model. It is found that the present model can generate relatively small spurious velocities and can capture interfacial dynamics with higher accuracy than the previously improved axisymmetric LB model. Besides, it is also found that our present numerical results show excellent agreement with analytical solutions or available experimental data for a wide range of density ratios, which highlights the strengths of the proposed model.
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Alternate Webpage(s)	https://export.arxiv.org/pdf/1810.09299
Language	English
Access Restriction	Open
Subject Keyword	Continuous Phase Dot-com bubble Email Entity Name Part Qualifier - adopted Equilibrium Flow Gradient HLA-DQ Antigens Hydrodynamics Interface Device Component Lattice Boltzmann methods Lattice corneal dystrophy Type I Lattice gas automaton Linear programming relaxation Markov chain Medial rostrotemporal auditory cortex Numerical analysis Numerical stability Quantum field theory Simulation Solutions
Content Type	Text
Resource Type	Article