Nonlinear Flow Properties of Newtonian Fluids through Rough Crossed Fractures  

作　　者：Zhenguo Liu Shuchen Li Richeng Liu Changzhou Zheng 

机构地区：[1]Geotechnical and Structural Engineering Research Center,Shandong University,Jinan,250061,China [2]Sinohydro Foundation Engineering Co.,Ltd.,Tianjin,301700,China [3]State Key Laboratory for Geomechanics andDeepUnderground Engineering,China University of Mining and Technology,Xuzhou,221116,China

出　　处：《Computer Modeling in Engineering & Sciences》2023年第8期1427-1440,共14页工程与科学中的计算机建模（英文）

基　　金：funded by National Key Research and Development Program of China,China (Grant No.2020YFA0711800);Natural Science Foundation of China,China (Grant Nos.51979272 and 51879150);Natural Science Foundation of Jiangsu Province,China (Grant No.BK20211584);Xuzhou Science and Technology Planning Project,China (Grant No.KC21004).

摘　　要：The nonlinear flow properties of Newtonian fluids through crossed fractures are estimated by considering the influences of length,aperture,and surface roughness of fractures.A total of 252 computational runs are performed by creating 36 computational domains,in which the Navier-Stokes equations are solved.The results show that the nonlinear relationship between flow rate and hydraulic gradient follows Forchheimer’s law–based equation.When the hydraulic gradient is small(i.e.,10^(−6)),the streamlines are parallel to the fracture walls,indicating a linear streamline distribution.When the hydraulic gradient is large(i.e.,10^(0)),the streamlines are disturbed by a certain number of eddies,indicating a nonlinear streamline distribution.The patterns of eddy distributions depend on the length,aperture,and surface roughness of fractures.With the increment of hydraulic gradient from 10^(−6) to 10^(0),the ratio of flow rate to hydraulic gradient holds constants and then decreases slightly and finally decreases robustly.The fluid flow experiences a linear flow regime,a weakly nonlinear regime,and a strongly nonlinear regime,respectively.The critical hydraulic gradient ranges from 3.27×10^(−5) to 5.82×10^(−2) when fracture length=20–100mmandmechanical aperture=1–5mm.The joint roughness coefficient plays a negligible role in the variations in critical hydraulic gradient compared with fracture length and/or mechanical aperture.The critical hydraulic gradient decreases with increasing mechanical aperture,following power-law relationships.The parameters in the functions are associated with fracture length.

关 键 词：Crossed fractures surface roughness APERTURE nonlinear flow critical hydraulic gradient 

分 类 号：O17[理学—数学]