GGSD Program Details for FTWORK

FTWORK

Category	Contaminant transport (2D FD)
Publisher	GeoTrans, Inc.
Platform	DOS
Status	Public domain
Description	FTWORK is a block-centred finite difference model for simulating 1D, 2D and quasi-3D steady-state and transient flow and transient single species solute transport in saturated media under confined and unconfined conditions. The model supports both areal and cross-sectional 2D simulations. The flow equation is posed in terms of hydraulic head, the transport equation in terms of concentration. The model handles heterogeneities and anisotropy for flow, advection, hydrodynamic dispersion, first order decay (chemical, biological or radioactive), and linear and non-linear equilibrium adsorption. The model includes a parameter estimation option of the steady-state flow equation, using a Gauss-Newton non-linear least-squares optimisation technique with a Marquardt correction to estimate hydraulic conductivity and recharge. The model supports variable grid block lengths in X-, Y-, and Z-direction and deformed coordinate approximation for variable thickness layers. Boundary conditions include prescribed head, prescribed concentration, prescribed flux of water (recharge) or solute mass, and head-dependent flux (for leakage to/from streams, to drains). It handles single and multi-aquifer wells and chemical sources and sinks. The model can be used in a quasi-3D mode. A textual pre-processor, PRE-FTW, operating under MS Windows provides for interactive data entry and editing. Output includes: summary of the input data, convergence error, array data (head and/or concentration, Darcy velocity, and saturation index), and, if parameter estimation is performed, summary statistics and parameter multipliers, and residuals, head and concentration distribution for spreadsheet or graphic post-processing, sensitivity coefficient generated in the parameter estimation procedure, computed heads and/or concentrations as function of time for selected nodes, head residual, head and/or concentration at end of simulation to be used as initial conditions for a subsequent run, and a cell-by-cell flux file.
Cost	US Dollars 250
Data formats supported	None stated
Supplier in United States of America	GeoTrans, Inc.
Supplier in United States of America	International Ground Water Modeling Center