采用图像法实时监测二维多孔介质溶质运移实验与模拟研究

Experimental and simulation study on real-time monitoring of solute transport in two-dimensional porous media using image method

为了对非干扰条件下二维多孔介质中溶质运移现象进行量化研究,进而探索介质条件、水动力条件对二维溶质运移的影响。文章设计了二维承压含水层物理模型,运用图像分析法监测示踪剂质量浓度,开展了不同流速、不同粒径条件下多孔介质溶质运移实验研究,使用交互式地下水(Interactive Groundwater,IGW)模型对溶质运移穿透曲线进行了模拟,研究结果表明:相同流速不同粒径条件下,介质粒径小,亮蓝溶液先穿透,对应的峰值质量浓度小,且弥散系数随着介质粒径的减小而增大;相同粒径不同流速条件下,流速越大,到达峰值质量浓度的时间越短且峰值质量浓度越大,弥散系数随着流速的增大而增大;IGW模型总体拟合精度较高,存在拖尾现象,且这种现象随着流速减小及粒径减小而更明显。

In order to quantify the phenomenon of solute transport in two-dimensional porous media under the condition of noninterference,the effect of medium and hydrodynamic conditions on the two-dimensional solute transport was explored.A two-dimensional physical model standing for a confined aquifer was designed,and an image analysis method to detect the concentration of tracer was presented.Solute transport experiments were conducted under the conditions of different flow velocities and particle sizes,respectively.The breakthrough curves were fitted by Interactive Groundwater(IGW)simulation.Main conclusions were drawn as follows:under the condition of different particle sizes with a unified flow velocity,with the decrease of particle size,the time that the brilliant blue began to penetrate became faster and the corresponding peak value became smaller,and the dispersion coefficient increased with the decreasing particle size;under the condition of different flow velocities with a unified particle size,with the increase of flow velocity,the peak arrival time became earlier and the peak value became larger,and the dispersion coefficient increased with the increasing flow velocity;the IGW simulation had higher fitting precision generally,the trailing phenomenon was existent and more obvious with the decreasing particle size and decreasing flow velocity.