Approximate analytic and numerical solutions for non-Darcian flow towards large-diameter well in confined aquifers

The non-Dacian flow towards large-diameter well in confined aquifers was investigated using the method based on the combination of the linearization method and Laplace transform. Both the dimensionless drawdowns inside the well and in the aquifer were obtained with the Stehfest numerical Laplace inversion method and corresponding numerical solution. A dimensionless non-Darcian hydraulic conductivity was introduced to describe the characteristics of flow. The results indicate that the drawdowns inside the well for difrerent approach the same asymptotic value at early stage of drawing, which reflects the effect of well bore storage. In the later stage, the dimensionless drawdowns both inside the well and in the aquifer decreases with the increase of . In the steady drawing period the dimensionless drawdown increases with the increase of dimension less distance and varies following the power function relationship. The comparison with the numerical solution indicates that the approximate analytical solution obtained by linearization method has some errors at early stage, but it becomes smaller in later stage.

Approximate analytic and numerical solutions for non-Darcian flow towards large-diameter well in confined aquifers Academic Article