STFLO: A Finite-Element Code for Steady-State Flow in Porous Media.

摘要

STFLO is a simple, linear, finite element code designed to simulate two-dimensional (areal or vertical) plane or axisymmetric ground-water flow in porous media. The code was originally developed at GeoTrans, Inc. It provides options for anisotropic material properties, confined conditions, leaky confining beds with steady-state leakage, distributed or point sources, and specified head or flux boundary conditions. A 4-node isoparametric quadrilateral element is implemented in the program, allowing both generally shaped quadrilaterals and triangles to be used in discretization. This documentation describes the mathematical model, solution techniques and computer code design. It also contains a detailed user manual. The use of STFLO to analyze nuclear waste disposal issues has been emphasized throughout the report. A link with the waste package performance assessment code WAPPA has been identified. STFLO can be used primarily to estimate the rate of ground-water flow through a waste package by simulating the steady-state flow in the waste package and the surrounding rock. Output from STFLO consists of a hydraulic head distribution and velocities at the center of each finite element. The main strengths of STFLO are that it is simple and inexpensive to apply. On the other hand, its application is limited to isothermal, steady-state flow in a porous medium. In Section 1.5 of this document the code custodianship and control is described along with the status of verification, validation and peer review of this report. (ERA citation 08:037443)