This study presents the effect of the flow velocity, which varies exponentially with time, on solute transport in a finite porous medium with radial geometry. The two-dimensional advection-dispersion equation in the cylindrical coordinate system is solved by using finite difference method. The concentration profiles are established for a duration of four hours of infiltration. It appears that the concentrations are lower in the case of the decreasing exponential velocity. The analysis of the effect of the injection radius showed that the retention of pollutants decreases when the injection radius increases. These findings can be used to design the size of a filter system for drinking water provision, and the environment protection.

本研究介绍了流速随时间呈指数变化的流速对径向几何有限多孔介质中溶质输运的影响。采用有限差分法求解柱坐标系下的二维平流色散方程。浓度分布是在四个小时的渗透持续时间内建立的。看来在指数速度减小的情况下浓度较低。分析注入半径的影响表明，当注入半径增大时，污染物的截留量减小。这些发现可用于设计用于饮用水供应和环境保护的过滤系统的尺寸。