摘要
为了研究越流含水层系统中大口径完整井附近地下水流动规律,根据Reynolds数将渗流场分为非达西流与达西流两个区域,提出了一种基于有限差分原理的迭代法,来模拟两区界面位置(RcD)随时间的变化规律,并采用实测数据验证本文解的实用性。结果表明:抽水初期,RcD很小,本文解与全达西流解析解几乎重合;抽水中期,RcD逐渐增大,解析解与数值解的降深曲线差别很明显,而在非达西流区域,本文解与全非达西流解析解的降深曲线斜率差别不大;在抽水后期,地下水流场达到稳定,RcD达到最大值,同时,在非达西流区域中,本文解与全非达西解吻合较好,在达西流区域,本文解与全达西流解吻合较好。RcD对井筒半径和滤水管半径比较敏感。当RcD趋于无穷大时本文解转化为全非达西流解;当RcD趋于0时本文解转化为全达西流解。
In this study,groundwater flowing to a large-diameter well in a leaky aquifer has been investigated.The groundwater flow around the well were divided into two regions,Darcian flow region and non-Darcian flow region,based on the critical Reynolds number.An iteration method was proposed by using the finite difference method to estimate the interface（RcD） of these two regions.The interface is assumed to be a moving interface,meaning that RcD is a function of pumping time.The solution obtained in this study can be used to estimate the aquifer parameters when the pumping data is available.The results show that RcD is small at early pumping stage and the new solution is almost the same as that of the one-region Darcian flow model.In the middle stage of pumping,RcD increases and the difference between the new solution and the former analytical solution is relatively larger,while the slope of the drawdown-time behavior for the new solution is almost the same as that of the one-region non-Darcian flow model.For the late stage of pumping,RcD approaches a maximum value,and the new solution is almost the same as that of one-region non-Darcian flow model for the non-Darcian flow region,and it is the same as that of one-region Darcian flow model for the Darcian flow region.RcD is sensitive to the values of the radius of well casing and well screen.The new solution becomes the one-region non-Darcian flow solution when RcD approaches infinite,while it becomes the one-region Darcian flow solution when RcD approaches 0.
出处
《水利学报》
EI
CSCD
北大核心
2012年第10期1171-1178,共8页
Journal of Hydraulic Engineering
基金
长江中游江-汉洞庭平原国土水资源综合监测示范(1212011120084)
国家自然科学基金项目(41002082)
中央高校基本科研业务费专项资金资助项目(CUG110401)
