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, constantdensity or densitydependent groundwater flow
and either singlespecies reactive solute transport or thermal energy transport.
Simulations can be either twodimensional or fully threedimensional. Solutions
can be either steadystate or transient. SUTRA's main features and
limitations are summarized below:
PHYSICS
 Groundwater flow
 saturated/unsaturated
 constantdensity or densitydependent
 userprogrammable unsaturated flow functions
 Transport
 single solute or thermal energy
 zeroth and firstorder solute production/decay; zerothorder
energy production/decay
 linear, Freundlich, or Langmuir adsorption
 Time dependence
 steadystate or transient solution
 timevarying boundary conditions specified via input files or programmable subroutine
GEOMETRY
 Twodimensional (2D) models
 Cartesian coordinates or
 radial/cylindrical coordinates
 Threedimensional (3D) models
 Cartesian coordinates
 fully 3D
NUMERICAL METHODS
 Discretization
 hybrid Galerkinfiniteelement and integratedfinitedifference method
 quadrilateral (2D) or generalized hexahedral (3D) finite elements
 fully implicit finitedifference time discretization
 Nonlinear problems
 Variabledensity 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 timedependent 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.
 Timevarying 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
 Textbased interface
 Compiled version available for Windows^{®}
 Can be run on any platform with a standard FORTRAN90 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 onscreen
 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 specifiedpressure,
specifiedconcentration, and specifiedtemperature boundary
conditions.
 Windows^{®}based
