Introduction to FLONET/TRANS
FLONET/TRANS is the fastest and easiest software package for 2-D cross-sectional groundwater flow and contaminant transport modeling. This unique modeling environment offers all the advantages of finite-element modeling (numerical stability and flexible geometry) together with a logical and intuitive graphical interface that makes finite-element modeling fast and easy, even for first-time users.
FLONET/TRANS uses the dual formulation of hydraulic potentials and streamlines to solve the saturated groundwater flow equation and create accurate flownet diagrams for any two-dimensional, saturated groundwater flow system. In addition, FLONET/TRANS also simulates advective-dispersive contaminant transport problems with spatially-variable retardation and multiple source terms.
Once you start using FLONET/TRANS, you will be amazed at how quickly and easily you are able to assemble the model, run the simulation and visualize the results. This fully-integrated package has everything you need to create simple or complex 2-D cross-sectional groundwater flow and contaminant transport models:
For 2-D cross-sectional groundwater flow and contaminant transport modeling, FLONET/TRANS is the software package you have been waiting for!
- Graphically assign all necessary flow and transport parameters,
- Run the simulation, and
- Visualize full-color results in several reporting formats.
Professional Applications of FLONET/TRANS
FLONET/TRANS is a complete graphical modeling environment specifically designed for cross-sectional groundwater flow and contaminant transport in unconfined, confined and leaky aquifers with heterogeneous soil properties and complex boundary conditions. Some typical applications of FLONET/TRANS include:
- Plotting Flownets and Streamlines Beneath and Through an Earth Dam
- Determining Groundwater Discharge Along a Seepage Face
- Estimating the Influence and Capture of Trench-and-Drain Remediation Systems
- Simulating Contaminant Plume Migration from a Landfill or Leaking UST
FLONET/TRANS is currently being applied by over 500 consultants around the world and is used as a valuable teaching and research tool at educational institutions worldwide. The ease-of-use and simplicity of FLONET/TRANS combined with the flexible design tools and comprehensive analysis capabilities, has made it a favorite for both expert modelers and practicing hydrogeologists.
FLONET/TRANS Main Features
- Automatic finite-element mesh generation
- Flexible mesh design (deformable mesh)
- Object-oriented properties and boundary conditions
- Spatially-variable soil properties
- Customizable display of equipotentials, streamlines, velocities and concentrations
- Plot concentration vs. time at multiple observation points
- Color-shading of all contoured results
About the FLONET/TRANS Interface
FLONET/TRANS has been specifically designed to increase modeling productivity and decrease the complexities typically associated with building groundwater flow and contaminant transport models. The FLONET/TRANS interface is divided into three separate modules: the Input Module, the Run Module, and the Output Module. When you open or create a file, you will be able to seamlessly switch between these modules to build or modify the model input parameters, run the simulations, and display results.
The FLONET/TRANS Input Module
The FLONET/TRANS Input Module allows the user to graphically assign all the necessary input parameters for building a two-dimensional groundwater flow and contaminant transport model. The input menus represent the basic 'building blocks' of a numerical model and are arranged in a logical order to guide the user through the normal sequence of steps required to design a groundwater flow and contaminant transport model.
The FLONET/TRANS Run Module
The FLONET/TRANS Run Module allows the user to select which analysis to perform (flow and/or transport) and modify the settings for the flow and transport solution methods.
The FLONET/TRANS Output Module
The FLONET/TRANS Output Module allows the user to display all the modeling results for the flow and transport simulation. The output menus allow you to select, customize and overlay the various options for displaying and interpreting the modeling results. All modeling results can be printed to any printer or plotter supported by Windows or exported to ASCII, DXF or WMF file formats. Specified output times (days)
FLONET/TRANS Model Design Features - The Input Module
Typically, with finite-element groundwater modeling, the process of building the input data file for a groundwater flow and/or transport model is often a cumbersome and time-intensive task best suited for those with an abundance of patience and an affinity for numerical programming. Now, with FLONET/TRANS, all that has changed. The logical menu structure of the FLONET/TRANS interface, together with the intuitive graphical tools, has eliminated these difficulties by guiding the user through the sequence of steps necessary to build, run and evaluate a complete groundwater flow and contaminant transport model.
Once you start using FLONET/TRANS, you will immediately realize the time-saving benefits of the powerful graphical tools that allow you to quickly and conveniently assign spatially-variable property distributions, multiple pumping wells, and complex boundary conditions.
FLONET/TRANS supports object-oriented boundary conditions and properties and provides liberal use of the mouse for digitizing boundary locations and spatially-variable property zones. The following section describes the sequence of FLONET/TRANS input screens and model building tools that are provided for creating your input data.
FLONET/TRANS automatically generates a uniformly-spaced finite-element mesh for the dimensions of the model domain. This mesh can be easily modified and deformed to match the geometry of the soil stratigraphy. A DXF map of the site cross section can be imported and overlaid on the model domain to guide the mesh design. Grid modification features include graphical tools to Add, Erase, Move, and automatically Refine rows and columns. In addition, individual nodes can be dragged in the vertical direction to deform the mesh in the vertical direction.
||Flow Boundary Conditions
Flow boundary conditions supported by FLONET/TRANS include Constant Head and Specified Flux. Model boundary conditions are assigned to single nodes or as lines along any boundary of the model. For linear boundary conditions, the boundary values are automatically interpolated between the start and end values defined by the user.
The aquifer properties which are accounted for in FLONET/TRANS include Hydraulic Conductivity (Kh and Kv), Porosity, Angle of Flow, and Retardation Coefficient. Soil properties are assigned using standard graphical tools including polygons and boxes. Each property zone is treated as an object with attributes that include a property ID number, property values, color and shape. Each of these attributes are tied to the object itself and are not affected by modifications to the model grid or other model parameters. Once these three steps have been completed, you can run the flow simulation to solve the groundwater flow model. The remaining input screens are required only for contaminant transport simulations
||Transport Boundary Conditions
The transport boundary conditions supported by FLONET/TRANS include Constant Concentration (Type I) and Flux Concentration (Type III). The Type I concentrations can be assigned to any node in the model domain while the Type III concentrations must be assigned on the same node as an existing flow boundary condition (constant head or specified flux). The transport boundary conditions can be assigned in either g/L, mg/L, or ug/L.
The flow properties accommodated by FLONET/TRANS include:
- Source Decay Rate (1/T)
- Contaminant Decay Rate (1/T)
- Longitudinal Dispersivity (L)
- Transverse Dispersivity (L)
- Diffusion Coefficient (L2/T)
All transport properties in FLONET/TRANS with the exception of retardation are assumed to be uniform throughout the entire model domain.
The initial concentrations for the simulation can be assigned as spatially-variable zones of specified concentrations throughout the model domain. Initial concentrations are assigned using standard graphical tools including polygons and boxes. Each concentration zone is treated as an object with attributes that include a property ID number, concentration value, color and shape. Each of these attributes are tied to the object itself and are not affected by modifications to the model grid or other model parameters
Any number of monitoring points can be assigned throughout the model domain to track the concentration at a specific location. Each monitoring point is assigned a name to associate it with a potential receptor or an observation well location at the site.
FLONET/TRANS Analysis Features - The Run Module
The Run Module allows the user to select which analysis to perform (flow, particle tracking and/or transport) and modify the settings for the flow and transport solution methods.
Flow Model Solution Settings
FLONET/TRANS solves the steady-state saturated flow equation using the dual formulation of hydraulic potentials and stream functions (E. O. Frind and Mantaga, 1985). For unconfined or semi-confined systems, this solution deforms the model grid to solve for the location of the water table. For confined systems, the model grid is not deformed during the solution process. This method is very stable and often results in solution times in the order of seconds as opposed to hours for less robust methods.
The solution settings allow you to specify the head change convergence criteria, number of iterations, and maximum number of deformable rows.
Contaminant Transport Solution Settings
FLONET/TRANS solves the contaminant transport problem using the standard two-dimensional equation for advective-dispersive transport with first-order decay and retardation. Before executing the contaminant transport simulation, FLONET/TRANS checks the flow simulation results against the transport input parameters and reports any violations of the Peclet number criterion (P<2) and the Courant number criterion (C<P/2).
- Initial time (days)
- Time step size (days)
- Number of time steps
- Number of output times
- Specified output times (days)
FLONET/TRANS Display Features - The Output Module
The ability to visualize the simulation results is almost as important as creating the model in the first place. In order to get the most out of the model you build, it is critical that you have the tools necessary to properly analyze and interpret the results. FLONET/TRANS allows you to capitalize on the full band of Windows colors to produce a striking displays of your modeling results. It provides a comprehensive selection of graphical displays and options to allow you to fully customize your results.
FLONET/TRANS allows you to produce and display customizable contour plots of the simulation results including:
FLONET/TRANS accommodates multiple contour plot overlays to display equipotentials, streamlines and concentrations on the same plot. The contour customization settings include:
- Streamlines, and
FLONET/TRANS can also overlay the input boundary conditions and property zones together with the graphical display of results.
- Min. and max. contour value,
- Contour increment value,
- Manual contour values,
- Contour labels ON/OFF, and
- Color shading threshold values and more.
The flow streamlines are very useful for indicating the groundwater flow pathways and are also commonly used to calculate the groundwater flux (discharge) along a seepage face. The streamline values are displayed in units of L2/T and represent the Darcy flux between each of the streamlines (flow tubes). The volumetric flow rate is calculated by multiplying (number of streamlines) x (streamline increment value) x (unit thickness of the cross-sectional model).
||Flow Velocity Vectors
The flow velocity vectors provide an important representation of the groundwater flow directions at specific locations throughout the model domain. Display options include setting the number of velocity vectors per line and adjusting the scale of the velocity vectors
FLONET/TRANS provides a graphical summary of the fluxes along the upper boundary of the model. The summary displays both the flux into the model and the discharge along seepage faces.
FLONET/TRANS prints full-color, high-resolution graphics to most printers and plotters. The graphical display of the simulation results and/or input files can be printed in portrait or landscape format with a title block that describes the details of the model and the results being displayed.
FLONET/TRANS also prints the on-screen display in several popular graphics file formats including BMP, TIF, and DXF.
FLONET/TRANS is accompanied by a comprehensive user's manual containing easy-to-follow instructions and a step-by-step tutorial. Free technical support is provided by phone, fax and e-mail.
FLONET/TRANS Requirements: PC Pentium running Windows 95 and Windows NT with 8 MB RAM and 10 MB free disk space.