PolyRES: A polygon-based Richards equation solver

Technical Report · Fri Dec 01 00:00:00 EST 1995

DOI:https://doi.org/10.2172/179180· OSTI ID:179180

Hills, R G ^[1]; Meyer, P D; Rockhold, M L ^[2]

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1. New Mexico State Univ., Las Cruces, NM (United States). Dept. of Mechanical Engineering
2. Pacific Northwest Lab., Richland, WA (United States)

This document describes the theory, implementation, and use of a software package designed to solve the transient, two-dimensional, Richards equation for water flow in unsaturated-saturated soils. This package was specifically designed to model complex geometries with minimal input from the user and to simulate groundwater flow related to assessment of low-level radioactive waste disposal sites and engineered facilities. The spatial variation of the hydraulic properties can be defined across individual polygon-shaped subdomains, called objects. These objects combine to form a polygon-shaped model domain. Each object can have its own distribution of hydraulic parameters. The resulting model domain and polygon-shaped internal objects are mapped onto a rectangular, finite-volume, computational grid by a preprocessor. This allows the user to specify model geometry independently of the underlying grid and greatly simplifies user input for complex geometries. In addition, this approach significantly reduces the computational requirements since complex geometries are actually modeled on a rectangular grid. This results in well-structured, finite difference-like systems of equations that require minimal storage and are very efficient to solve. The documentation for this software package includes a user`s manual, a detailed description of the underlying theory, and a detailed discussion of program flow. Several example problems are presented that show the use and features of the software package. The water flow predictions for several of these example problems are compared to those of another algorithm to test for prediction equivalency.

• Research Organization: US Nuclear Regulatory Commission (NRC), Washington, DC (United States). Div. of Regulatory Applications; New Mexico State Univ., Las Cruces, NM (United States). Dept. of Mechanical Engineering; Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 179180
• Report Number(s): NUREG/CR-6366; PNL-10709; ON: TI96004527; TRN: 96:004424
• Resource Relation: Other Information: PBD: Dec 1995
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
99 MATHEMATICS
COMPUTERS
INFORMATION SCIENCE
MANAGEMENT
LAW
MISCELLANEOUS
RADIOACTIVE WASTE FACILITIES
HYDROLOGY
GROUND WATER
FLOW MODELS
P CODES
MANUALS
POROUS MATERIALS
RADIOACTIVE WASTE DISPOSAL
UNDERGROUND DISPOSAL
LOW-LEVEL RADIOACTIVE WASTES
HYDRAULIC CONDUCTIVITY
COMPUTER PROGRAM DOCUMENTATION
SOIL MECHANICS
COVERINGS