Πρόγραμμα Ανάλυσης Μεταφοράς Ρυπαντών με Πεπερασμένα Στοιχεία
CTRAN/W is part of an integrated suite of five geotechnical software packages being used extensively throughout the world on six continents and in more than 70 countries. They are used by practicing engineers for the analysis and design of a wide variety of structures and by universities for teaching and research. The five state-of-the-art software packages for geotechnical modeling in the Microsoft Windows environment are:
- SLOPE/W for slope stability
- SEEP/W for groundwater seepage
- SIGMA/W for stress and deformation
- TEMP/W for geothermal analysis
CTRAN/W models contaminant transport through soil and rock. The comprehensive formulation of CTRAN/W makes it possible to analyze a wide range of problems. Problems may be as simple as tracking particles in response to the movement of water or as complex as analyzing processes involving diffusion, dispersion, adsorption, and radioactive decay.
More computed parameters such as concentration can be contoured. The total advective, dispersive, stored, and decayed flux can be displayed on the flux section.
CTRAN/W is integrated with SEEP/W and has the same Microsoft Windows CAD-like graphical user interface as SEEP/W. The two software products must be used together to analyze contaminant transport. SEEP/W computes the water flow velocity, water content, and water flux. CTRAN/W uses these parameters to compute the contaminant migration.
When a contaminant enters the ground, the dissolved constituents will migrate due to the movement of the water. This process is called advection. In addition, the contaminant disperses due to hydrodynamic mixing and molecular diffusion. In the absence of dispersion, the dissolved mass would migrate as a "plug" at full concentration. The migration also may be retarded due to adsorption and radioactive decay.
CTRAN/W has a finite-element SOLVE function to analyze advection-dispersion processes with optional mass losses due to adsorption and decay, as well as a TRACK function to model only advection.
In an advection-dispersion analysis, a user-defined concentration can be contoured for each time step on a single plot.
The integration with SEEP/W makes it possible to model contaminant transport for:
- Simultaneous saturated and unsaturated flow
- Steady-state and transient water flow conditions
- Transient hydraulic boundary conditions
- Anisotropic and heterogeneous ground conditions
Advection and dispersion affect the contaminant concentration.
CTRAN/W features specific to mass transport analysis include:
- Transient concentration and mass flux boundary conditions
- Free exit boundary conditions
- Molecular diffusion coefficient as a function of volumetric water content
- Independent coefficients of dispersivity in two orthogonal directions
- Adsorption as a function of concentration
- Mass loss due to radioactive decay
- Total, advective, and dispersive mass flux across user-specified sections
- Simulation of transport through fractured rock
- A time-step sequence independent of the corresponding SEEP/W analysis
CTRAN/W can model contaminant movement by tracking data points (particles) from user-defined locations. You can place a particle anywhere in the flow system by clicking at a particular point. After TRACK has moved the particles within the flow system, CONTOUR displays the particle migration paths. Particles are tracked as they move forward from the source; alternatively you can introduce particles at the sink or exit point and track them "backward" to the source. This allows you to establish the origin of the contaminant from a known exit point. The region between any two particle migration paths can be shaded to highlight the contaminated region. Specific information about a particle's migration can be displayed by clicking at any point along the computed particle migration path.
VIEWING AND PLOTTING
Variables that can be contoured and graphed include: Concentration; Total, fluid, and solid mass; Adsorption; Peclet and Courant numbers; Dispersive coefficients; and Flow velocities. CONTOUR allows you to display the total accumulated mass in the system including the portion in the fore fluid and the portion adsorbed by the soil particles. You can also display the accumulated mass within any element or any group of elements.
The purely-advective component of contaminant migration can be analyzed by tracking the movement of particles. The particle travel time, distance traveled, and average speed can be displayed at any point along the particle migration path.
Computed parameters can be plotted as a function of time or space.
CTRAN/W Version 4 Enhancements
Version 4 of CTRAN/W provides a leap into the world of 32-bit computing and advanced Windows environments. Version 4 is 32-bit software that runs under Windows 95 and Windows NT allowing you to analyze your problems faster and easier.
Density-Dependent Transport Analysis
For problems where the density of the contaminant is significantly different than water, CTRAN/W has the capability of performing density-dependent transport analyses. This feature is useful for solving problems related to sea water intrusion, brine transport and landfill leachate migration. CTRAN/W SOLVE performs density-dependent transport analyses by running SEEP/W SOLVE and solving the coupled groundwater flow and contaminant transport governing equations simultaneously using an iterative procedure within each time step. The analysis can be applied to both saturated and unsaturated soils.
Improved User Interface
- Five toolbars have been added to DEFINE and CONTOUR for quicker access to commonly-used commands: a Standard toolbar, Zoom toolbar, Grid toolbar, Mode toolbar and View Preferences toolbar. These toolbars can be placed anywhere in the DEFINE or CONTOUR window or can be hidden from view.
- A status bar has been added to the bottom of the DEFINE and CONTOUR windows. The status bar displays information relevant to the CTRAN/W command you are using. Whenever a menu command is highlighted or the mouse is over a toolbar button, a brief description of the command is displayed in the status bar. The status bar also displays the current mouse position.
- The toolbar commands can often be accessed while you are in another mode. For example, if you are using the Modify Objects command and wish to select a group of text items, you can display text on the drawing by selecting the View Sketch Objects button in the View Preferences toolbar; you do not have to exit the mode first.
- The File menu in DEFINE and CONTOUR now lists the previous six CTRAN/W problems that you have opened. This allows you to quickly open a problem you have been working on.
- Long file names are supported for CTRAN/W problems. For example, instead of naming your problem MCREKDAM.CTR, you can name it Micah Creek Dam.ctr.
- The new Windows 95 common dialog boxes are supported for commands such as File Open, File Save, and File Print. The new File Print dialog box allows you to print your drawing to any connected printer, not just the default printer.
Online Help and User's Guide
- The complete CTRAN/W User's Guide has been converted into Microsoft Help format; online help can be accessed directly from CTRAN/W by choosing Help Topics from the Help menu.
- You can get immediate help on any command by choosing the command and pressing the F1 key or clicking on the question-mark button in any CTRAN/W dialog box; CTRAN/W launches the online help and displays the appropriate topic.
- CTRAN/W online help uses the Windows 95 help system. This system allows you to search for any word or phrase in the CTRAN/W User's Guide or to view the online help through a table of contents or an index.
- The CTRAN/W User's Guide is included on the Version 4 CD-ROM in Microsoft Word format; a printed copy of the User's Guide is not included with CTRAN/W Version 4. To print a copy of the User's Guide, install the Word Viewer from the CTRAN/W CD-ROM, open each chapter in the CTRAN/W User's Guide and print it.
Unlimited Number of Time Steps
There is no longer any limit on the number of time steps that you can use in a problem.
Improved Particle Tracking
SOLVE now automatically calculates the time increment used to move the particle through the flow system. This time increment will always satisfy the Courant number criterion. As a result, particles are moved correctly, regardless of the size of the user-specified time increments. In Version 3, the particle was tracked linearly between each user-specified time increment, causing the particle to deviate from its true path when the specified time increment was too large.
Improved Contour Shading
- Each contour region can now be shaded a different color. You can control the shading color by specifying a color for the first contour and a color for the last contour. CTRAN/W interpolates between these two colors to shade the entire contour range.
- CTRAN/W provides five different methods for interpolating between the starting and ending colors. You can choose from a number of "rainbow" color schemes or apply a simple linear interpolation between the starting and ending colors.
- You can specify the number of colors for each contour interval. If you use one color per interval, then each contour interval is clearly visible as a distinct color. If you use several colors per interval, then the contour shading blends smoothly from one color to the next within the contour interval.
Color Selection for Soil Layers
You can now assign a specific color to each material. CTRAN/W uses these colors when it displays the element shading. You can choose any color you wish.
Improved Mesh Generation
Version 4 allows you to generate finite elements within a triangular region, not just a quadrilateral region. CTRAN/W fills most of the triangular region with quadrilateral elements; triangular elements are generated along the third side of the triangular region.
You can now specify an element size distribution within the quadrilateral or triangular region. This allows you to increase the size of the elements from one part of the region to another.
The Multiple Elements dialog box allows you to see the generated elements before you decide to accept them. This allows you to experiment with the element generation parameters until you are satisfied with how the elements appear; you can then accept the generated elements or cancel the operation.
Graphical Modification of Problem Geometry
The Version 3 Delete and Move commands have been replaced with a single Modify Objects command in Version 4. Modify Objects is a powerful command that allows you to select any combination of objects on the drawing and then move, re-size, or delete them. Object types include text, lines, circles, arcs, flux sections and scaled axes. If you wish to modify nodes and elements, you can use the Modify Objects command in SEEP/W Version 4 and them re-import your mesh into CTRAN/W.
Plan View Infiltration
For a plan view analysis, you can now specify a unit mass flux boundary (qm) condition at any node; SOLVE computes the contributing area of the node and then computes the resulting total nodal mass flux (Qm) at the node.
Initial Concentration Definition
If you know the initial concentration at all nodes, you are no longer required to first perform a one time step advection-dispersion analysis. In DEFINE, you can now specify the initial concentration value at any node; SOLVE uses these values as the initial concentrations for the analysis.
Exit Review Boundary
You can now specify mass flux type (qm, Qm and Cs) boundary nodes as an exit review boundary. SOLVE reviews these nodes for exit conditions and automatically converts them to free exit boundaries when required. This feature is useful for solving problems with transient boundary conditions that may change certain nodes to free exit conditions during the transport process.
- The TRACK program has been merged into the SOLVE program; you can now use SOLVE to perform a particle tracking analysis.
- Contributing areas for q boundary conditions are now calculated in SOLVE, not in DEFINE.
- The File Export command now supports the Enhanced Metafile Format (EMF) as well as the Windows Metafile Format (WMF). The DXF format is no longer supported by File Export; other Windows programs, such as QuarterDeck HiJaak, can be used to convert a WMF or EMF file into DXF or many other file formats.
- The CTRAN/W Network version now supports TCP/IP over a local subnet when you are using the Windows NetSentinel server program. The Windows server program can be run under Windows NT or Windows 95.
- Draw Element Properties allows you to interactively modify element integration order and thickness, not just the element material number.
- CTRAN/W now stores each user's default settings in the Windows registry. You no longer need to save your settings in a CT0 file.
- A boundary function can now be "cycled"; this allows you to specify, for example, a concentration boundary function for a tailings pond over a one year period and then analyze the problem over ten years.
- KeyIn Project ID now allows you to sketch the project title on the drawing.
- Many other minor improvements to DEFINE, SOLVE, and CONTOUR.
486/Pentium (Pentium recommended) with 16 MB RAM and FORTRAN Compiler. Any Workstation, e.g., IBM RS6000, DEC Alpha, Silicon Graphics, Sun SparcStation, and HP 9000 Series.
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Τελευταία Ενημέρωση 27 Ιουλίου 2004 - Last Revised on July 27th 2004
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