This web page summarizes SUTRA's capabilities and limitations, input data
requirements, and associated preprocessing and postprocessing utilities. For
more information about SUTRA and its utilities, see the formal documentation
for each code,
and take advantage of the various other resources
offered on this website.
Capabilities and Limitations of SUTRA
SUTRA simulates saturated and/or unsaturated, constant-density or density-dependent groundwater flow
and either single-species reactive solute transport or thermal energy transport.
Simulations can be either two-dimensional or fully three-dimensional. Solutions
can be either steady-state or transient. SUTRA's main features and
limitations are summarized below:
PHYSICS
- Groundwater flow
- saturated/unsaturated
- constant-density or density-dependent
- user-programmable unsaturated flow functions
- Transport
- single solute or thermal energy
- zeroth- and first-order solute production/decay; zeroth-order
energy production/decay
- linear, Freundlich, or Langmuir adsorption
- Time dependence
- steady-state or transient solution
- time-varying boundary conditions specified via input files or programmable subroutine
GEOMETRY
- Two-dimensional (2D) models
- Cartesian coordinates or
- radial/cylindrical coordinates
- Three-dimensional (3D) models
- Cartesian coordinates
- fully 3D
NUMERICAL METHODS
- Discretization
- hybrid Galerkin-finite-element and integrated-finite-difference method
- quadrilateral (2D) or generalized hexahedral (3D) finite elements
- fully implicit finite-difference time discretization
- Nonlinear problems
- Variable-density and/or unsaturated flow problems are nonlinear
- Picard iteration available to resolve nonlinearities
- Matrix equation solvers
- Gaussian elimination (direct)
- preconditioned CG (iterative; only for flow equation without
upstream weighting)
- preconditioned GMRES (iterative)
- preconditioned ORTHOMIN (iterative)
INPUT AND OUTPUT
- Input
- all input data are contained in text files
- input data are grouped into "datasets"
- Output
- output is written to text files and to the screen
- flexible, columnwise listing of pressure, concentration or
temperature, saturation, and velocity
- observation well output (pressure, concentration or
temperature, and saturation vs. time)
- fluid mass and solute mass or energy budgets
- Preprocessing and postprocessing
software (details below)
- facilitates formulation of input datasets
- helps with interpretation of results
Input data requirements for SUTRA
For each SUTRA simulation, the user must specify the type of simulation, mesh
structure, physical properties, simulation and output controls, boundary
conditions, and initial conditions. This is done through two or more data files:
- the main input (".inp") file
- the initial conditions (".ics") file
- one or more (".bcs") files for time-dependent boundary conditions
The input data requirements are summarized below:
TYPE OF TRANSPORT
- Solute transport or
- Energy transport
MESH STRUCTURE
- Node and element numbering scheme
- Coordinates in space of each node
- (x, y) in 2D
- (x, y, z) in 3D
- Thickness of the mesh at each node (2D only)
- For each element, a list of nodes that form its corners
PHYSICAL PROPERTIES
SIMULATION AND OUTPUT CONTROLS
- Simulation title
- Simulation dimensions
- number of nodes
- number of elements
- number of boundary conditions
- number of observation nodes
- Simulation modes
- saturated/unsaturated
- steady/transient
- run initialization
- storage of restart information
- Numerical controls
- upstream weighting
- enforcement of boundary conditions
- time stepping
- solution cycling
- Picard iterations
- matrix solver parameters
- Output controls
- nodewise results (pressure, concentration, saturation)
- elementwise results (velocity)
- fluid mass and
solute mass or energy budgets
- results at observation nodes
- screen output
BOUNDARY CONDITIONS
- Four types of boundary conditions
- Fluid sources or sinks
- Solute mass or energy sources or sinks
- Specified pressures
- Specified solute concentrations or temperatures
- Specification of boundary conditions
- All boundary conditions are specified at nodes.
- Boundary conditions are not restricted to nodes
at the physical boundary of the model; they can be specified at any
node.
- By default, there is no flux of mass or energy in or out of the model domain at any
node for which a boundary condition is not explicitly specified.
- Time-varying boundary conditions can be specified using the optional ".bcs" input files or programmed by the user in
subroutine BCTIME.
INITIAL CONDITIONS
- Initial conditions
- starting time
- initial pressure at each node
- initial solute concentration or temperature at each node
- Restarting a run
- A restart (".rst") file contains initial conditions, plus additional
initialization information saved by SUTRA at the end of an earlier run.
- Using the information saved in a restart file, an earlier run can be continued
as though it had never been interrupted. This is called a
"warm" start.
- The restart file can also be used in a "cold start" to
continue a run after changes have been made to the model input
(e.g., different boundary conditions).
Preprocessing and postprocessing
utilities
Preprocessing software facilitates the formulation of large, complex input
datasets. Once a simulation is completed, postprocessing software can assist in
the interpretation of results. The SutraSuite software package includes a number of preprocessing and postprocessing
programs designed for use with SUTRA. These are summarized in the table
below:
PREPROCESSING
SOFTWARE
- SutraPrep
- Simple preprocessor for 3D SUTRA problems
- Creates input for SUTRA 2.0 [2D3D.1], which can be read by SUTRA 2.1 and 2.2
- Creates 3D (VRML) mesh plots
- Text-based interface
- Compiled version available for Windows®
- Can be run on any platform with a standard FORTRAN-90 compiler
- SutraGUI
- Powerful graphical user interface (GUI) for 2D and 3D SUTRA problems
- Features interactive graphical input and ability to import GIS maps of physical properties and
boundary conditions
- Also does postprocessing (2D only) -- see below
- Windows®-based
- Requires ArgusONE® software
POSTPROCESSING
SOFTWARE
- SutraPlot (version compatible with versions of SUTRA higher than 2.0 [2D3D.1] is currently under development)
- Plots results of 2D and 3D SUTRA simulations
- Creates mesh plots, contour plots, and velocity vector plots
- Windows®-based
- SutraGUI
- Plots results of 2D SUTRA simulations
- Creates contour plots of pressure, concentration/temperature, and
saturation, and plots velocity vectors
- Also does preprocessing (2D & 3D) -- see above
- Windows®-based
- Model Viewer
- Creates visualizations of 2D and 3D SUTRA output that the user can manipulate on-screen
- Plots isosurfaces or solid, 3D maps of pressure,
concentration/temperature, or saturation
- Plots velocity vectors
- Saves visualizations as bitmaps (.bmp) or VRML plots (.wrl)
- Displays animations of results and exports frames for creating
animations outside of Model Viewer
- Windows®-based
- GW_Chart
- Plots results of 2D and 3D SUTRA simulations as functions
of time: fluid, solute, and energy budgets;
and pressure and concentration or temperature at observation nodes
- Windows®-based
- CheckMatchBC
- Aids
in the proper formulation of specified-pressure,
specified-concentration, and specified-temperature boundary
conditions.
- Windows®-based
|