Movement of a liquid front in an unsaturated, fractured porous medium, Part 2, Mathematical theory.

摘要

A simplified equation of motion is derived for the flow of liquid through an idealized one-dimensional fracture situated in an unsaturated imbibing porous medium. The equation is valid for the case where the matrix material has a much lower saturated conductivity than that of the fracture and the capillary tension in the matrix is sufficiently stronger than gravity. Asymptotic solutions are given for the motion of the liquid front in a parallel fracture system. With the introduction of natural time constants and dimensionless parameters, the flow behavior can be shown to possess various temporal flow regimes. This work is part of the Nevada Nuclear Waste Storage Project and is applicable to understanding some of the various physical parameters affecting liquid flow through a fracture in an unsaturated porous medium, and is particularly useful as a step in understanding the hydrological processes around a nuclear waste repository in an unsaturated environment as well as in other applications where unsaturated fracture flow conditions exist. The solutions are also relevant to numerical model verification. 10 refs., 2 tabs.