|Water Science and Engineering 2014, 7(3) 277-287 DOI: doi:10.3882/j.issn.1674-2370.2014.03.004 ISSN: 1674-2370 CN: 32-1785/TV|
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Lattice Boltzmann simulation of solute transport in a single rough fracture
Zhi DOU*, Zhi-fang ZHOU
School of Earth Sciences and Engineering, Hohai University, Nanjing 210098, P. R. China
In this study, the lattice Boltzmann method (LBM) was used to simulate the solute transport in a single rough fracture. The self-affine rough fracture wall was generated with the successive random addition method. The ability of the developed LBM to simulate the solute transport was validated by Taylor dispersion. The effect of fluid velocity on the solute transport in a single rough fracture was investigated using the LBM. The breakthrough curves (BTCs) for continuous injection sources in rough fractures were analyzed and discussed with different Reynolds numbers (Re). The results show that the rough fracture wall leads to a large fluid velocity gradient across the aperture. Consequently, there is a broad distribution of the immobile region along the rough fracture wall. This distribution of the immobile region is very sensitive to the Re and fracture geometry, and the immobile region is enlarged with the increase of Re and roughness. The concentration of the solute front in the mobile region increases with the Re. Furthermore, the Re and roughness have significant effects on BTCs, and the slow solute molecule exchange between the mobile and immobile regions results in a long breakthrough tail for the rough fracture. This study also demonstrates that the developed LBM can be effective in studying the solute transport in a rough fracture.
|Keywords： solute transport single rough fracture lattice Boltzmann method self-affinity breakthrough curve|
|Received 2013-05-28 Revised 2013-12-06 Online: 2014-07-25|
This work was supported by the National Natural Science Foundation of China (Grants No. 51079043, 41172204, and 51109139) and the Natural Science Foundation of Jiangsu Province (Grant No. BK2011110).
|Corresponding Authors: Zhi DOU|
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