文献类型：期刊文献

英文题名：Nonlinear fluid flow through three-dimensional rough fracture networks: Insights from 3D-printing, CT-scanning, and high-resolution numerical simulations

作者：Li, Bo[1];Wang, Jiafei[1];Liu, Richeng[2,3];Jiang, Yujing[3]

机构：[1]Shaoxing Univ, Key Lab Rock Mech & Geohazards Zhejiang Prov, Shaoxing 312000, Peoples R China;[2]China Univ Min & Technol, State Key Lab Geomech & Deep Underground Engn, Xuzhou 221116, Jiangsu, Peoples R China;[3]Nagasaki Univ, Sch Engn, Nagasaki 8528521, Japan

年份：2021

卷号：13

期号：5

起止页码：1020

外文期刊名：JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING

收录：SCI-EXPANDED(收录号：WOS:000699979000006)、、Scopus(收录号：2-s2.0-85112004328)、WOS

基金：This study has been partially funded by the Natural Science Foundation of Zhejiang Province (Grant No. LR19E090001) and the Natural Science Foundation of China (Grant Nos. 42077252, 42011530122, and 51979272). These supports are gratefully acknowledged.

语种：英文

外文关键词：Nonlinear flow; 3D-printing; CT-scanning; Fracture network; Permeability; Fluid flow test

外文摘要：Nonlinear flow behavior of fluids through three-dimensional (3D) discrete fracture networks (DFNs) considering effects of fracture number, surface roughness and fracture aperture was experimentally and numerically investigated. Three physical models of DFNs were 3D-printed and then computed tomography (CT)-scanned to obtain the specific geometry of fractures. The validity of numerically simulating the fluid flow through DFNs was verified via comparison with flow tests on the 3D-printed models. A parametric study was then implemented to establish quantitative relations between the coefficients/parameters in Forchheimer's law and geometrical parameters. The results showed that the 3D-printing technique can well reproduce the geometry of single fractures with less precision when preparing complex fracture networks, numerical modeling precision of which can be improved via CT-scanning as evidenced by the well fitted results between fluid flow tests and numerical simulations using CT-scanned digital models. Streamlines in DFNs become increasingly tortuous as the fracture number and roughness increase, resulting in stronger inertial effects and greater curvatures of hydraulic pressure-low rate relations, which can be well characterized by the Forchheimer's law. The critical hydraulic gradient for the onset of nonlinear flow decreases with the increasing aperture, fracture number and roughness, following a power function. The increases in fracture aperture and number provide more paths for fluid flow, increasing both the viscous and inertial permeabilities. The value of the inertial permeability is approximately four orders of magnitude greater than the viscous permeability, following a power function with an exponent alpha of 3, and a proportional coefficient beta mathematically correlated with the geometrical parameters. (C) 2021 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V.