WANG Pei-tao, HUANG Hao, ZHANG Bo, et al. Characterization of rough fracture model and the seepage characteristics based on 3D printing technology[J]. 2024, 45(3): 725-736.
DOI:
WANG Pei-tao, HUANG Hao, ZHANG Bo, et al. Characterization of rough fracture model and the seepage characteristics based on 3D printing technology[J]. 2024, 45(3): 725-736.DOI: 10.16285/j.rsm.2023.0875.
Characterization of rough fracture model and the seepage characteristics based on 3D printing technology
基于Weierstrass-Mandelbrot(W-M)分形函数开展三维粗糙结构面表征,讨论了W-M典型几何参数对三维曲面形态影响,分析确定对应于典型Barton节理JRC轮廓线的二维与三维W-M几何参数。基于自主设计结构面渗流测试系统,结合3D打印开展不同分形参数和开度的裂隙渗流试验,试验结果表明:随着水力梯度和粗糙度的增加,流体的流动表现出明显的非线性,Forchheimer方程的系数A与B都随着裂隙粗糙度的增加而增大,随着裂隙开度的增加而减小;随着裂隙粗糙度的增加,临界雷诺系数Rec 趋于减小,说明流体流动趋于非达西流动。光滑表面流体的流场流速比较均匀;粗糙裂隙表面流场更加复杂,整个粗糙面上存在多个高流速区域和低流速区域。研究成果可为裂隙渗流特性研究提供了可靠的分析方法和模型。A three-dimensional roughstructural surface characterization was carried out based on theWeierstrass-Mandelbrot (W-M) fractal function. The effects of typical W-Mgeometric parameters on the three-dimensional surface morphology were discussed.The two-dimensional and three-dimensional W-M geometric parameterscorresponding to typical Barton JRCcurves were analyzed and provided. Experimental fracture seepage tests onspecimens with different fractal parameters and fracture aperture were conductedusing a self-designed fracture seepage system based on 3D printing technology.The test results showed that the fluid flow exhibited obvious nonlinearity withincreasing hydraulic gradient and roughness. The coefficients of A and B in the Forchheimer equation increased with increasing fractureroughness and decreased with increasing fracture aperture. Meanwhile
thecritical Reynolds coefficient tended to decrease as the roughness increased
indicating a tendency towards non-Darcy flow. The analysis of fluid flowpatterns revealed that the flow velocity of the smooth structure surface of themodel was relatively uniform. The flow field of the rough surface was complexshowing several high and low flow velocity regions along the rough surfaces.The research results provide reliable analytical methods and models for thestudy of fracture seepage characteristics.