| Abstrakt: |
A more realistic theoretical solution to the problem of unsteady flow to a single, partially penetrating well of finite radius in an unconfined aquifer is developed. The aquifer is assumed to be homogeneous, isotropic, and infinite both in thickness and lateral extent. Perturbation expansion techniques are used to linearize the free surface boundary condition, so that the solution satisfies the boundary conditions through first order in the small parameter ϵ, provided that the drawdowns remain small, and that a time limit is imposed. The basic potential field is created by distributing dipole moments over the surface of the well bore and solving the resulting integral equation numerically. The solution can be used to model pumped well behavior for the initial period after the start of pumping. A more accurate model of pumped well behavior is possible with this solution, since it is not restricted to the constant flow rate or constant head modes of simulation. Results show that the assumption of constant discharge operation in earlier, more approximate solutions to this problem is more realistic than the assumption of constant head operation. [ABSTRACT FROM AUTHOR] |
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