A series of laboratory experiments on water flow through rough fractures was performed using self-designed experimental devices to investigate the effect of fracture roughness on the flow behavior. Nine models of single rough fractures—with three joint roughness coefficients (JRCs) of 0–2, 8–10 and 18–20, and three apertures for each JRC—were prepared using three-dimensional printing technology. In the flow experiments, the values of Reynolds numbers ranged widely from less than 10 to around 10,000. According to the experimental data, the fracture roughness has an obvious influence on the hydraulic properties of fractures. A parametric expression for the Forchheimer equation was proposed to quantitatively describe the influence of fracture roughness on the flow behaviour in the fractures. The relations between the parameters for nonlinear flow (such as critical Reynolds number, non-Darcy effect coefficient and friction factor) and the JRCs were obtained. It was found that the critical Reynolds number decreased significantly from 566 to 67 as the JRC increased from 2 to 20. The increase in fracture roughness causes more extra energy losses and enhances the degree of flow nonlinearity in single fractures.

使用自行设计的实验装置对流经粗糙裂缝的水进行了一系列实验室实验，以研究裂缝粗糙度对流动行为的影响。使用三维打印技术，准备了9个单一的粗糙裂缝模型-三个关节粗糙度系数（JRC）分别为0-2、8-10和18-20，每个JRC具有三个孔。在流动实验中，雷诺数的值范围从小于10到大约10,000。根据实验数据，裂缝的粗糙度对裂缝的水力性能有明显的影响。提出了Forchheimer方程的参数表达式，以定量描述裂缝粗糙度对裂缝流动行为的影响。得到了非线性流动参数（如临界雷诺数，非达西效应系数和摩擦系数）与JRC之间的关系。已发现，随着JRC从2增加到20，临界雷诺数从566显着降低到67。裂缝粗糙度的增加导致更多的额外能量损失，并增强了单个裂缝的流动非线性程度。