1. NAME AND TITLE

FE3DGW: Code System for Finite-Element, Three-Dimensional Ground-Water Flow Analysis.

2. CONTRIBUTOR

Office of Nuclear Waste Isolation, Battelle Memorial Institute, Columbus, Ohio.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; VAX.

4. NATURE OF PROBLEM SOLVED

FE3DGW is a code system for analyzing flow through large, multilayered ground-water systems. The code has the capability to model noncontinuous and continuous layering, time-dependent and constant sources/sinks, and transient as well as steady state flow. The code offers a wide choice in specifying boundary conditions like prescribed heads, nodal injection or withdrawal, constant or spatially varying infiltration rates, and elemental source/sink. Initial conditions can be prescribed as vertically hydrostatic or variable hydraulic head. The heterogeneity in aquifer permeability and porosity can be described by geologic unit or explicitly for given elements.

5. METHOD OF SOLUTION

The code solves the partial differential equation for hydraulic head in large, multilayered natural systems by the finite element method. The geologic input data for a complex, multilayered ground-water system is reduced to hydrologic interpretation in the form of well logs at each surface node and subdivision of the entire region into two-dimensional elements. To facilitate interaction between disciplines, support programs were developed for plotting the finite element grid with well logs (PLOTEL3D), drawing contour maps (FEPLTI and FEPLT), and generation of rectangular grid data from irregular grid data to display three-dimensionally both the input data used for the simulation and the results (GRIDFE). The graphic displays are generated directly from the simulation input and output files. The program, TVL3D, delineates travel pathlines and travel times for use in radionuclide and other contaminant transport codes.

6. RESTRICTIONS OR LIMITATIONS

The code does not account for density variation and calculates only the hydraulic heads.

7. TYPICAL RUNNING TIME

The computational codes required only a few seconds to execute each of the sample cases on the VAX 8600.

8. COMPUTER HARDWARE REQUIREMENTS

This VAX 11/780 version is an update of the PDP 11/70 version and was tested by RSIC on a VAX 8600.

9. COMPUTER SOFTWARE REQUIREMENTS

This version was implemented under the VMS 3.5 operating system and tested by RSIC under VMS 4.7. The proprietary CalComp and DISSPLA graphics software were used to generate graphical output.

10. REFERENCE

S. K. Gupta, C. R. Cole, F. W. Bond, and A. Monti, "Finite-Element Three-Dimensional Ground-Water (FE3DGW) Flow Model: Formulation, Computer Source Listings, and User's Manual," BMI/ONWI-548 (October 1984).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and sample problem input and output.

12. DATE OF ABSTRACT

August 1988.