Detailed Features of SVHeat 1D/2D

SVHeat implements a comprehensive list of features which are outlined as follows:

Simulation Features

• Steady-state analysis.
• Transient (time dependant) analysis.
• Saturated or unsaturated analysis.
• Customizable solutions through a modifiable governing partial differential equation.
• Flux sections may be placed at any location in the model to summarize energy flux across a section.
• Energy flux with time may be tracked across flux sections.
• Finite element analysis by the Galerkin method. The solver uses advanced features such as preconditioning of the convergence matrix as well as staging and automatic mesh refinement to achieve solutions with greater stability than any other software currently available.
• Solver runs on Red Hat Linux or Windows with support for hyper-threading and multiple processors.
• Fully automatic mesh generation. Mesh generation may be limited by a maximum number of nodes or by a maximum specified error.
• Fully automatic mesh refinement. Mesh refinement is based on the relative error of the governing equation and therefore automatically locates critical zones. In a transient analysis a different mesh is generated for each time step. SVHeat is currently the only geothermal package in the world to offer this feature. Read more about adaptive grid refinement in research published by Mansell, 2002.
• Fully automatic time-step refinement for transient analysis. The time-steps selected by the solver are independant of the plotting intervals selected by the user.
• SVHeat is designed to model the transition between frozen and unfrozen soils. Functional properties such as thermal conductivity versus temperature and unfrozen water content versus temperature may be entered to describe the phase change relationship between ice and water. Specific heat may be specified to follow the contant or Newman formulation.

Model Design Features

• CAD style entry of geometry.
• Grid, snapping, and object snapping features available.
• Zooming, panning features available.
• Import AutoCAD DXF geometry and incorporate it directly in the model. The automatic mesh generation will automatically allign node points with line segment end points.
• Graphically assign boundary conditions.
• Head or flux boundary conditions may be specified as contants or free-form equations. Free form equations may be specified as a function of position or time (i.e. T=30+exp(time)*2.5+x*0.8)
• Problems may be entered in Metric or Imperial units
• All aspects of all models are stored in a database which may be placed on a server. Multiple users may be "plugged in" to the same modeling database.
• Initial water contents may be imported from an SVFlux analysis.
• A central database of soil properties for all entered geothermal problems is maintained. New problems may draw soils from existing problems.
• Problem geometry may be imported from existing problems.
• Existing problems may be saved under a new name in the database to allow quick generation of multiple scenarios.
• Colors or patterns of soil regions may be specified.
• Manual entry of region coordinate points.
• Lines may be added to model to force mesh refinement along a linear object.
• Internal boundary conditions may be set or node density specified along internal line objects.
• Sketch text or lines may be added to the model design.
• Graphical model design may be exported as a WMF or DXF file and/or printed.
• Bitmaps may be imported and layered behind model geometry to simplify model creation.

Output Features

• Color contour plots of temperature, unfrozen water content, or thermal conductivity may be produced. Custom color shadings may be specified.
• Plots may be zoomed to isolate any region of interest.
• Vector plots of thermal gradients.
• Volume or water volume integrals may be computed over the entire problem or any particular region of interest.
• Mesh plots track mesh refinement.
• Plots of value versus time may be generated at any coordinate for the following values: temperature, unfrozen water content, or thermal conductivity.
• Surface plots of any 2D variable over the problem region may be produced.
• Overlaying of plots may be performed. For example, vectors may be shown in Region 1 while contours of head may be shown in Region 2.
• Text and line art may be added to output.
• Graphical output may be exported to WMF, EMF, DXF, GIF, or BMP formats.
• Transient results may be animated.
• Plotting of thermal flowlines is possible.

Applications

• Thermal design of roads and airstrips.
• Ground freezing for soil stabilization.
• Insulation design for shallow buried piping
• Thawing beneath heated or chilled structures.
• Freezing around chilled pipelines.
• Temperature variation over large areas with significant relief.

Documentation

The following manuals document the operation of the SVHeat software. The design of the software makes it simple to learn and use. Most users are able to learn how to use the software effectively to create 2D problems within 30-60 minutes.

• User's manual - documents specific operation of software.
• Tutorial manual - Step-by-step instructions guide the user through creation of 2D and 3D problems.
• Theory manual - documents the theory of the governing partial differential equations used in the solution of the geothermal problem.
• Verification manual - benchmarks the SVHeat software against typical seepage problems published in texts, journal papers, or manuals from other software packages.

System Requirements

• SVHeat2D runs on Windows 95/98, NT 4.0, Me, 2000, and XP. The recommended minimum hardware configuration is a P266 with 128MB RAM and 35 MB hard disk space.