Integrated into the GeoStudio Suite
TEMP/W is integrated into the GeoStudio
suite, and therefore has access to
the GeoStudio features for creating
your model, analyzing it, and viewing results.
Comprehensive Conduction, Convection, and Phase Change Formulation
TEMP/W uses a finite element-based formulation
to analyze thermal changes in the ground due to environmental changes or due to
the construction of facilities such as buildings or pipelines. The
comprehensive formulation makes it possible to analyze both simple and highly
complex geothermal problems. TEMP/W can be applied to the geothermal analysis
and design of geotechnical, civil, and mining engineering projects, including
facilities subjected to freezing and thawing temperature changes.
The TEMP/W formulation includes conduction,
forced-convection, and phase change, making it possible to analyze such
problems as permafrost changes due to climate change, the effect of man-made
structures on the geothermal regime, or ground freezing applications in
groundwater flow systems.
The phase change formulation in TEMP/W
accounts for the latent heat associated with water turning into ice and ice
turning into water. The rate at which the latent heat is absorbed or released
is controlled by an unfrozen water content function. Above the phase change temperature,
all the water is unfrozen. As the temperature falls below the phase change
point, the portion of the water that remains unfrozen decreases. Complete
flexibility in defining the unfrozen water content function makes it possible
to analyze a wide variety of ground conditions. When linked with SEEP/W or
AIR/W it can consider convective heat transfer of flowing water or moving air.
TEMP/W can model almost any geothermal
- Degradation of permafrost
due to man-made structures
- Ground freezing for soil stabilization, including use of freezing pipes around mine shafts or thermosyphons on top of earth dams
- Freeze-thaw action beneath roadways and airport runways
depth penetration beneath chilled structures such as a recreational ice surface
or a highway during the winter
- Climate effects on the ground surface energy balance
- Development of a frost bulb around a chilled pipeline
- Assessment of various insulation alternatives for reducing freezing and/or thawing
- Analysis and design of frozen capillary cover barriers
- Groundwater flow control design
Get converged solutions for difficult problems
The introduction of the latent heat of
phase change into a heat transfer analysis introduces a significant amount of
non-linearity into the analysis. This non-linearity is manifest in numerical
oscillation during the iterative solution process. TEMP/W implements a rigorous convergence criterion and
under-relaxation scheme, making it possible to model demanding freeze-thaw
problems, as well as models with a large spatial variability in temperatures
across the domain. Graphing tools are available during run-time to help you
judge if convergence has been achieved.
Estimate Material Properties from Measured Data
TEMP/W provides convenient material
estimation capabilities for determining the thermal conductivity, unfrozen
water content, and volumetric heat capacity functions.
Use Simplified or Full Thermal Material Models
Different problems require different levels
of sophistication for defining the material properties. TEMP/W provides a simplified material
model that considers only unfrozen and frozen conditions, while incorporating
phase change at a single phase change temperature. TEMP/W also includes a full-thermal
material model that makes thermal conductivity a function of temperature, while
phase change occurs over a temperature range as defined by the unfrozen
volumetric water content. The
general thermal conductivity function makes it possible to consider a smooth
transition in conductivity as the temperature changes from thawed to frozen
conditions and vice versa. Using the full thermal material model allows you to analyze
problems in which the presence of ice in the pore-space plays a role in the
thermal response of the system.
Model Land-Climate Interaction
There are many problems in geotechnical
engineering that involve a coupling between climatic conditions and the thermal
response within the ground. These
types of problems can be analyzed in TEMP/W using the Surface Energy Balance boundary condition.
TEMP/W uses climate data to determine evaporation rates, snow accumulation and snowmelt. A surface energy balance approach is used to determine the resulting energy flux over the ground surface and subsequent ground temperatures.
Thermosyphons are used in many cold regions
to extract energy from the ground to maintain frozen ground conditions. TEMP/W implements a rigorous
thermosyphon boundary condition that can accommodate either two-dimensional or
Convective Heat Transfer Boundary Condition
The convective heat transfer boundary
condition provides a convenient approach for the simulation of artificial
ground freezing or other processes involving the flow of fluid over or within a
Forced Convection with Water Flow
Heat transfer is often governed by forced convection in natural hydrogeological systems. TEMP/W can be fully integrated with SEEP/W to analyze heat transfer via groundwater flow.
Coupled Convective Material Model
The coupled-convective material model can
be used for an integrated TEMP/W and SEEP/W analysis, adjusting the thermal
conductivity and volumetric heat capacity as the ratio of pore-water, pore-air,
and pore-ice changes duration the transient seepage analysis.
Forced Convection with Air Flow
Many geotechnical engineering problems,
such a heat movement in mine-site waste dumps, involve density-driven air
flow. TEMP/W can be integrated
with AIR/W to seamlessly model heat transfer via conduction and
forced-convection with the moving air.
Convenient Initial Condition Definition
Initial conditions for transient analyses
can be determined using a variety of options including a spatial temperature
function, region temperature activation, or results from another GeoStudio
finite element analysis.
Initial Temperature for Activated Materials
Materials can be activated with a specified
temperature for transient analyses, providing a convenient way to set the
initial condition for entire regions in which the starting condition is nearly
Model in 1D, 2D, Axisymmetric or Plan View
TEMP/W includes analysis options for
modelling pseudo three-dimensional problems such as heat extraction from a
Powerful Graphing of Results
Graphing is critical for the interpretation
of a heat transfer analysis. The powerful graphing options in GeoStudio make it
possible to plot critical information in TEMP/W such as the location of the
freeze front through time, the energy extracted or input into the system, heat
flux rates, and more. All of this
data can be exported or copy/pasted directly into spreadsheet software.
Visualize Flow Paths and Flux across Sections
Once the analysis is complete, you can
interactively click on any part of the domain to visualize the actual flow path
through this point. You can also set up flux sections to calculate the amount
of flow across the section during the analysis.
Sensitivity Analysis with TEMP/W
A sensitivity analysis can be readily
conducted with TEMP/W by cloning multiple analyses using the Analysis Tree, and
then making slight changes to each one.
Optimization and Calibration
TEMP/W can be paired with other software to
conduct optimization/calibration of material properties.