On the unintentional rarefaction effect in LBM modeling of intrinsic permeability
On the unintentional rarefaction effect in LBM modeling of intrinsic permeability
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DOI：
10.26804/ager.2018.04.05
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发表时间：
2018-08
影响因子：
8.2
通讯作者：
Jun Li;M. Ho;Lei Wu;Yonghao Zhang
中科院分区：
文献类型：
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作者：
Jun Li;M. Ho;Lei Wu;Yonghao Zhang
格子Boltzmann方法（LBM）已被应用于预测多孔介质的流动特性（包括固有渗透率），其中隐含地假设LBM等价于不可压缩（或接近不可压缩）的Navier-Stokes方程。然而，在LBM模拟中，在Navier-Stokes方程中完全忽略的高阶矩仍然可以通过粒子分布函数获得。为了确保LBM模拟在Navier-Stokes流体动力学水平上正确工作，高阶矩必须可以忽略。这就要求Knudsen数（Kn）很小，从而可以忽略稀疏效应。在我们的研究中，我们阐述了多孔介质流动的LBM建模中的这个问题，这对于超致密介质中的气体流动特别重要。文中还讨论了雷诺数Re对本征渗透率的影响。
Lattice Boltzmann method (LBM) has been applied to predict flow properties of porous media including intrinsic permeability, where it is implicitly assumed that the LBM is equivalent to the incompressible (or near incompressible) Navier-Stokes equation. However, in LBM simulations, high-order moments, which are completely neglected in the Navier-Stokes equation, are still available through particle distribution functions. To ensure that the LBM simulation is correctly working at the Navier-Stokes hydrodynamic level, the high-order moments have to be negligible. This requires that the Knudsen number (Kn) is small so that rarefaction effect can be ignored. In our study, we elaborate this issue in LBM modeling of porous media flows, which is particularly important for gas flows in ultra-tight media. The influence of Reynolds number (Re) on the intrinsic permeability is also discussed.