Multiphase cascaded lattice Boltzmann method
Multiphase cascaded lattice Boltzmann method
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DOI：
10.1016/j.camwa.2013.08.033
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
D. Lycett-Brown;K. Luo
中科院分区：
文献类型：
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作者：
D. Lycett-Brown;K. Luo
为了提高格子Boltzmann方法在高雷诺数下的稳定性，最近引入了级联LBM。与多重弛豫时间（MRT）方法一样，级联LBM在碰撞算子中引入了额外的弛豫时间，但在共同移动的参考系中这样做。这已经显示出在单相情况下在低粘度下显著增加稳定性。这里，级联LBM进一步发展为包括多相流。为此，力项通过相互作用势方法计算，并通过精确差分方法（EDM）引入碰撞算子。与晶格Bhatnagar-Gross-Krook（LBGK）方法和MRT实现进行了比较。级联和MRT方法都显示出显着减少虚假的LBGK方法的速度。对于特殊情况下的山-陈粒子间力项计算与EDM，级联LBM成功地结合了多相方法，并表现出更成熟的MRT方法。级联LBM被发现是一个相当大的改进的方法来模拟多相流的LBGK，显着增加的密度比和雷诺数的稳定范围。此外，包括三阶速度项的级联和MRT方法的平衡的重要性进行了讨论。
To improve the stability of the lattice Boltzmann method (LBM) at high Reynolds number the cascaded LBM has recently been introduced. As in the multiple relaxation time (MRT) method the cascaded LBM introduces additional relaxation times into the collision operator, but does so in a co-moving reference frame. This has been shown to significantly increase stability at low viscosity in the single phase case. Here the cascaded LBM is further developed to include multiphase flow. For this the force term is calculated by the interaction potential method, and introduced into the collision operator via the exact difference method (EDM). Comparisons are made with the lattice Bhatnagar–Gross–Krook (LBGK) method, and an MRT implementation. Both the cascaded and MRT methods are shown to significantly reduce spurious velocities over the LBGK method. For the particular case of the Shan–Chen interparticle force term calculation with the EDM, the cascaded LBM is successfully combined with a multiphase method, and shown to perform as well as the more established MRT method. The cascaded LBM is found to be a considerably improved approach to the simulation of multiphase flow over the LBGK, significantly increasing the stability range of both density ratio and Reynolds number. Additionally the importance of including third order velocity terms in the equilibria of both the cascaded and MRT methods is discussed.