A study of wall boundary conditions in pseudopotential lattice Boltzmann models
A study of wall boundary conditions in pseudopotential lattice Boltzmann models
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DOI：
10.1016/j.compfluid.2018.05.011
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发表时间：
2019-10
影响因子：
2.8
通讯作者：
S. Khajepor;Jinghao Cui;M. Dewar;Baixin Chen
中科院分区：
文献类型：
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作者：
S. Khajepor;Jinghao Cui;M. Dewar;Baixin Chen
研究了流固相互作用对非理想流体的流体力学性质和表面润湿性的影响。我们将赝势模拟的相互作用力集成到两个现场边界条件中：标准反弹（SBB）和Zou和He（ZH）[12]，以确定边界节点的分布函数。测试了三种不同的相互作用力：基于赝势的相互作用（pseudopotential-based interaction，简称pseudopotential-based interaction，简称m-pseudopotential-based interaction，简称m-pseudopotential-based interaction），以及本研究基于ZH方法提出的基于ZH的相互作用。因此，这些方案是m-SBB、m-SBB、m-ZH和ZH-ZH。第一个标准是实现宏观Poilluille流。第二个标准是实现广泛的接触角。模拟的主要方法是多赝势相互作用[30]。结果表明，在双折射-SBB方案下，通道内的密度起伏较大。同时，m-SBB、m-ZH和ZH-ZH的方案在整个通道上产生小得多的密度变化。其中，ZH-ZH处理是上级的基础上的密度波动和与分辨率，弛豫时间和压缩性的误差。我们发现，所有四个边界条件可以形成一个广泛的接触角。在液滴表面上，液滴内部的密度起伏最大. m-SBB和m-ZH方案产生的密度涨落几乎相同，但都比ZH-ZH方案大。此外，m-SBB和ZH-ZH中的伪速度非常接近自由液滴，而m-SBB和ZH-ZH中的伪速度分别高达自由液滴的6倍和8倍。因此，ZH-ZH在润湿性测试中也表现最好。
The effect of fluid–solid interactions on the hydrodynamics of non-ideal fluids and wettability of surfaces is investigated. We integrate the interaction forces, simulated by pseudopotentials, into two on-site boundary conditions: standard bounce-back (SBB) and Zou and He (ZH) [12] to determine the distribution functions of the boundary nodes. Three different interaction forces are tested: pseudopotential-based interaction (ψ), modified pseudopotential-based interaction (mψ), and a ZH-based interaction, which is proposed by this study based on the ZH method. Therefore, the schemes are ψ-SBB, mψ-SBB, mψ-ZH, and ZH-ZH. The first criterion is the achievement of macroscopic Poiseuille flow. The second criterion is the achievement of a wide range of contact angles. The main method of simulation is multipseudopotential interaction [30]. It is found that the scheme of ψ-SBB creates a relatively large fluctuation of density across the channel. Whilst, the schemes of mψ-SBB, mψ-ZH, and ZH-ZH generate much less density variation across the channel. Among them, ZH-ZH treatment is superior based on density fluctuation and the error associated with the resolution, relaxation time, and compressibility. We found that all four boundary conditions can form a wide of range of contact angles. The ψ-SBB scheme creates largest density fluctuation inside a drop on wettable surfaces. The schemes of mψ-SBB and mψ-ZH create almost the same density fluctuation which is larger than ZH-ZH. Moreover, mψ interaction generates spurious velocities as high as six times a free drop with SBB and eight times with ZH while spurious velocities in ψ-SBB and ZH-ZH are very close to the free drop. Therefore, ZH-ZH performs best, also, in wettability tests.