Mathematical model for effective gas diffusion coefficient in multi-scale fractal porous media

被引：2
|
作者：
Mou X. [1 ]
Chen Z. [1 ]
机构：
[1] School of Energy and Environment, Southeast University, Nanjing
来源：
Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) | 2019年 / 49卷 / 03期
关键词：
Fractal; Gas diffusion; Multi-scales; Porous media;
D O I：
10.3969/j.issn.1001-0505.2019.03.017
中图分类号：
学科分类号：
摘要：
Based on the capillary hypothesis and fractal theory, a mathematical model for calculating the effective gas diffusion coefficient in porous media was established. By using the fractal geometry theory, the pore area fractal dimension, the tortuosity fractal dimension and the pore connectivity were introduced to quantitatively characterize the real internal structure in the porous media, and the fractal model for the microscopic pore structure in the porous media was established. The gas diffusion in the porous media on different scales was systematically studied. An effective gas diffusion coefficient model for the fractal porous media was derived, and the influence of multi-scale porous media microstructure parameters on the effective gas diffusion coefficient was discussed. The results show that effective gas diffusion coefficient approximates to linearly increase with the increase of porosity, the pore area fractal dimension and the effective gas diffusion coefficient is positive correlation, but the tortuosity fractal dimension is negative correlation with it. In the case of different porosities, the gas effective diffusion coefficient varies with the change of the pore diameter ratio, the effective gas diffusion coefficient increases with the increase of pore connectivity. © 2019, Editorial Department of Journal of Southeast University. All right reserved.
引用
收藏
页码：520 / 526
页数：6
相关论文
共 21 条
  • [1] Zheng Q., Yu B.M., Wang S.F., Et al., A diffusivity model for gas diffusion through fractal porous media, Chemical Engineering Science, 68, 1, pp. 650-655, (2012)
  • [2] Cao L.Y., He R., Gas diffusion in fractal porous media, Combustion Science and Technology, 182, 7, pp. 822-841, (2010)
  • [3] Martinez L., Florido-Diaz F.J., Hernandez A., Et al., Characterisation of three hydrophobic porous membranes used in membrane distillation: Modelling and evaluation of their water vapour permeabilities, Journal of Membrane Science, 203, 1-2, pp. 15-27, (2002)
  • [4] Moggridge G.D., Diffusion-Mass Transfer in Fluid Systems, pp. 13-90, (1984)
  • [5] Perfect E., Applications of fractals in soil and tillage research: A review, Soil and Tillage Research, 36, 1-2, pp. 1-20, (1995)
  • [6] Adler P.M., Thovert J.F., Real porous media: Local geometry and macroscopic properties, Applied Mechanics Reviews, 51, 9, pp. 537-585, (1998)
  • [7] Yu B.M., Analysis of flow in fractal porous media, Applied Mechanics Reviews, 61, 5, (2008)
  • [8] Xu P., A discussion on fractal models for transport physics of porous media, Fractals, 23, 3, (2015)
  • [9] Zhang L.Z., A fractal model for gas permeation through porous membranes, International Journal of Heat and Mass Transfer, 51, 21-22, pp. 5288-5295, (2008)
  • [10] Xiong J.Y., Zhang Y.P., Wang X.K., Et al., Two scale model for predicting the VOC diffusion coefficient in porous building materials, Journal of Engineering Thermophysics, 29, 12, pp. 2091-2093, (2008)
123