Abstract |
A numerical method programmed for a high-speed computer was developed for determining the drawdown around an artesian well. A salient feature of the program is that it can be used for both fully and partially penetrating wells in either infinite or finite aquifers. The method involves the application of finite difference equations to the well-known heat equation using a graded network. A comparison of the finite difference solutions with those obtained from the close-form formulas of Muskat, Theis, and Hantush indicates the validity of the method. A comparison between the finite difference solutions and the drawdowns measured on a sand model, consisting of a circular aquifer 8 feet in diameter and 4 feet thick with a well at the center, shows that the drawdowns in the well are in fairly good agreement, although some discrepancy exists at points outside the well. The discrepancy is believed due to the time lag caused by the use of small tubes as piezometers. If a correction for the time lag is made, the agreement between numerical solutions and experimental measurements is considered satisfactory within the range of experimental errors. (Author) |