In present engineering applications, calculations of hydraulic properties in two-phase flow are still highly dependent on empirical or semi-empirical equations obtained from experiments. However, the empirical equations that can reproduce the experiment data on a certain fracture specimen may have errors on other specimens. Researchers have obtained results that show quite different evolution forms of hydraulic characteristics of two-phase flow, which is induced by the variety of the influencing factors in two-phase flow. This paper aims at expanding the experimental results on the hydraulic characteristics of two-phase flow in rock fractures. With a newly developed experiment system, visualized two-phase flow experiments were introduced. The difference in the surface morphology of the fractures leads to totally different flow structures, which indicates the role of capillary pressure differs due to different fracture surfaces. The relative permeability in the rough specimen approximately follows the Corey model, which confirmed that the pressure drop is in this rough fracture is dominated by the capillary pressure, but the relative permeability is not only the function of saturation, but also the function of water flow velocities. However, the relative permeability is not perfect for evaluating the difference of two-phase hydraulic characteristics induced by the fracture surface morphology. On the contrary, the Lockhart-Martinelli model is appropriate for evaluating the difference in the two-phase hydraulic characteristics between the smooth fracture and the rough fracture, which indicates that the two-phase flow turbulence is obviously increased by the fracture roughness.

在当前的工程应用中，两相流中水力特性的计算仍然高度依赖于从实验中获得的经验或半经验方程。但是，可以在某个断裂样本上重现实验数据的经验方程式在其他样本上可能会有误差。研究人员获得的结果表明，两相流水力特性的演化形式大不相同，这是由两相流中各种影响因素引起的。本文旨在扩展岩石裂缝中两相流水力特性的实验结果。利用新开发的实验系统，引入了可视化的两相流实验。裂缝表面形态的差异导致完全不同的流动结构，这表明毛细管压力的作用因断裂面不同而不同。粗糙样品中的相对渗透率近似遵循Corey模型，这证实了该粗糙裂缝中的压降主要由毛细管压力决定，但相对渗透率不仅是饱和度的函数，而且还是水流的函数。速度。然而，相对渗透率对于评估由裂缝表面形态引起的两相水力特性的差异并不完美。相反，Lockhart-Martinelli模型适用于评估光滑裂缝和粗糙裂缝之间的两相水力特性差异，这表明裂缝的粗糙度明显增加了两相流动湍流。