LBM模拟固有渗透率时附带的稀薄气体效应

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LBM模拟固有渗透率时附带的稀薄气体效应

Ager,2018, 2(4): 404-409

原文网址: http://www.astp-agr.com/index.php/Index/Index/detail?id=84

  近年来，格子波尔兹曼（LBM）方法被广泛应用于预测固有渗透率等多孔介质的流动特性，其中LBM被默认为等价于不可压（或近不可压）N-S方程。然而，在LBM模拟中高阶矩依然存在于粒子分布函数的描述中，但在N-S方程的描述中被完全忽略。为了保证LBM在N-S方程尺度成立，高阶矩应该小到可忽略不计，这需要无量纲努森数Kn很小、从而稀薄气体效应可忽略。

沙特法赫德国王石油与矿业大学李军博士（King Fahd University of Petroleum & Minerals）与英国斯特拉斯克莱德大学Minh Tuan Ho博士、吴雷副教授及张勇豪教授（University of Strathclyde）详细讨论了LBM模拟多孔介质流动时的努森数效应，这在致密介质内的流动模拟中尤为重要。此外该论文也讨论了雷诺数（Re）对固有渗透率模拟的影响。

On the unintentional rarefaction effect in LBM modeling of intrinsic permeability

Jun Li, Minh Tuan Ho, Lei Wu, Yonghao Zhang

(Published: 2018-08-22)

CorrespondingAuthor and Email: Jun Li, lijun04@gmail.com

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Citation: Li, J., Ho, M.T., Wu, L., Zhang, Y. On the unintentional rarefaction effect in LBM modeling of intrinsic permeability. Advances in Geo-Energy Research, 2018, 2(4): 404-409, doi: 10.26804/ager.2018.04.05.

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ArticleType: Original article

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Abstract：

    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.

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Keywords: Lattice Boltzmann method, pore-scale simulations, Knudsen number.