粗糙单裂隙溶质运移优先通道的模拟研究  

Numerical Modeling of Preferential Flow and Transport Channel between Rough-Walled Fractures

作　　者：余成[1] 雷文武[1] 

机构地区：[1]重庆交通大学河海学院,重庆400074

出　　处：《重庆交通大学学报（自然科学版）》2015年第4期91-94,139,共5页Journal of Chongqing Jiaotong University(Natural Science)

基　　金：国家自然科学基金项目(51409028);重庆交通大学科研启动基金项目(2010310002)

摘　　要：为考察岩石粗糙裂隙内不均匀分布的裂隙空间对溶质运移过程的影响,采用基于LCL方法的数值模型对不同裂隙宽度下的流场和溶质运移过程进行模拟。结果表明:随着裂隙宽度减小,流场逐渐从均匀的平行板流过渡到强烈不均匀的沟槽流,流线逐渐集中于部分优先沟槽通道;溶质运移锋面的推进也从基本呈直线状平行推进,逐渐开始不规则化,出现指流现象;随着宽度继续减小,沟槽通道进一步发展,形成贯穿整个流场的溶质运移优先通道;优先运移通道的溶质运移速度远大于其他部位,出现某些部位溶质运移受困而滞留的现象。因此,在裂隙宽度较小时,粗糙裂隙内的优先沟槽通道对裂隙流动和溶质运移过程有着非常重要的影响。In order to show the impact of non-uniform void space on the flow and transport processes between rough-walled fractures,LCL modeling was employed to simulate the process of the solute transport under the flow with different crack width. The result suggests that,along with the decrease of fracture apertures,the flow field tends to get irregular,and streamlines tend to concentrate at preferential flow channels. Solute concentration front looks parallel when the fracture aperture is still significant,but gets irregular and looks similar to finger flow while fracture aperture decreases. As apertures decrease,preferential channels tend to form preferential transport channels. Solute transport speed at preferential transport channels tends to be much higher,thus some of the solute at low permeable regions seems to be trapped,or retarded within fractures. Therefore it can be concluded that when fracture apertures are small,preferential channels have significant impact on flow and transport processes between rough fractures.

关 键 词：水利工程 粗糙裂隙 溶质运移 数值模拟 优先沟槽通道 

分 类 号：P641.2[天文地球—地质矿产勘探]