宽隙比及粗糙度对交叉裂隙高速非达西偏流效应的影响

The Effect of Aperture Ratio and Roughness on the Deflection of High-speed Non-Darcy Seepage Flow in Intersection Fractures

目前针对交叉裂隙偏流现象的研究只局限于达西情况下,而实际工程中地下水渗流常常出现高速非达西现象。基于已有研究的基础,利用Fluent软件分别对不同隙宽比和不同粗糙度的交叉裂隙中的渗流进行数值模拟,以研究交叉裂隙在高流速下的非达西偏流效应特性。通过设置变量裂隙和参照裂隙,探讨两条支裂隙隙宽比以及节理粗糙度系数JRC对达西与非达西情况下偏流量的影响;同时对比了不同隙宽、不同粗糙度的单裂隙的渗流量与交叉裂隙分支裂隙的渗流量。结果表明相比于单裂隙,高流速下交叉裂隙各支裂隙的惯性项系数β减小;这种现象在宽裂隙及粗糙度较小的裂隙中尤为明显;并且在高速非达西条件下,交叉裂隙中的偏流现象更为显著。

The studies about the deflection in intersection fractures are only about the Darcy seepage flow.However it often comes to high-speed non-Darcy seepage flow in the groundwater in many projects.Based on the previous studies,a series of simulations with different aperture ratio and joint roughness coefficient(JRC)in high speed were done by Fluent for the purpose of studying the deflection of non-Darcy features of the seepage flow in intersection fractures.Variable fracture and reference fracture are set for contrast.It studied the effect of the two factors on the flow rate of Darcy and non-Darcy flow.At the same time,simulations of single fractures with the two factors to compare with the intersection fractures were did.The result shows that in high speed,compared with single fracture theβof each fracture in intersection fractures is lower,especially in the wider and less rough fracture.The deflection flow in intersection fractures is much more obvious in high speed Non-Darcy flow than in the Darcy flow.