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Title: PolyRES: A polygon-based Richards equation solver

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 presentedmore » 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.« less
Authors:
 [1] ; ;  [2]
  1. New Mexico State Univ., Las Cruces, NM (United States). Dept. of Mechanical Engineering
  2. Pacific Northwest Lab., Richland, WA (United States)
Publication Date:
OSTI Identifier:
179180
Report Number(s):
NUREG/CR--6366; PNL--10709
ON: TI96004527; TRN: 96:004424
DOE Contract Number:
AC06-76RL01830
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Dec 1995
Research Org:
Nuclear Regulatory Commission, Washington, DC (United States). Div. of Regulatory Applications; New Mexico State Univ., Las Cruces, NM (United States). Dept. of Mechanical Engineering; Pacific Northwest Lab., Richland, WA (United States)
Sponsoring Org:
Nuclear Regulatory Commission, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
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