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Pressure boundary condition in a multiphase lattice Boltzmann method and its applications on simulations of two‐phase flows
Author(s) -
Wang Lei,
Peng ZeRui
Publication year - 2020
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.4800
Subject(s) - lattice boltzmann methods , pressure gradient , mechanics , boundary value problem , physics , two phase flow , displacement (psychology) , open channel flow , mathematics , flow (mathematics) , classical mechanics , mathematical analysis , psychology , psychotherapist
Summary As a lattice Boltzmann method, He‐Chen‐Zhang model is widely used in two‐phase simulations. However, the pressure boundary conditions applied in He‐Chen‐Zhang model have hardly been discussed in detail before. In this article, a pressure boundary condition for single‐phase flows is extended to He‐Chen‐Zhang model for simulating two‐phase flows in porous media or in channel. Several cases are conducted for validation. Qualitatively, the displacement of two‐phase flows in porous media or in channel is reproduced; the manipulations of droplet in T‐junction, duct, or needle are simulated. These numerical results match well with the basic physical reality. Quantitatively, we tested the displacement of two‐phase fluids in a channel under specified pressure gradient, and it is found that the velocity profile on the crosssection coincides with the analytical solution exactly. Moreover, for stable displacement of two‐phase flows in a channel, the numerical linear relation between the apparent contact angle and the velocity of contact line coincides well with the theoretical result reported before. The present pressure boundary condition proves to be a reliable method to deal with the problems of two‐phase flows, which are driven by pressure difference.