Integrated into the GeoStudio Suite
CTRAN/W is integrated into the GeoStudio
suite, and therefore has access to
the GeoStudio features for creating
your model, analyzing it, and viewing results. CTRAN/W relies on SEEP/W to perform groundwater flow analysis required for simulating mass transport.
Comprehensive Solute and Gas Transport Formulation
CTRAN/W uses a finite element based
formulation to model the movement of solutes and gases through porous materials such
as soil and rock. The comprehensive formulation of CTRAN/W makes it possible to
analyze problems from simple transport due to water movement, to complex processes involving diffusion, dispersion,
adsorption, radioactive decay and density dependencies. CTRAN/W can be applied
to the evaluation and design of geotechnical, civil, hydrogeological, and mining
CTRAN/W is designed to be used in tandem
with a seepage analysis such as SEEP/W to analyze contaminant transport. SEEP/W
computes the water flow velocity, volumetric water content, and water flux.
CTRAN/W uses these parameters to compute the contaminant migration.
CTRAN/W can model almost any solute or gas transport problem, including:
Flow of contaminants from a surface pond
Flow of dissolved hydrocarbons
Flow of radioactive contaminants
- Gas and solute transport through fractured rock
Sea-water intrusion into coastal aquifers
Landfill leachate migration
- Gas movement through an unsaturated mine cover
Formulated for Saturated and Unsaturated Soils
CTRAN/W is formulated for saturated and
unsaturated transport, allowing the coefficient of diffusion to vary with water
content and the advection process to adjust as groundwater velocities change in
the unsaturated zone. In addition, CTRAN/W is capable of modelling changes in mass within a system caused by variation in water content due to processes like drainage, condensation, and vaporization.
Model Sorption and Kinematic Reactions
Solutes and gases often do not exhibit conservative behaviour while moving through soil and rock formations. Consequently, CTRAN/W is formulated to simulate many of the mechanisms contributing to this behaviour, including equilibrium sorption and first-order kinematic reactions such as radioactive decay, biodegradation, and hydrolysis.
Dual Phase Gas Transport
The gas transfer formulation gives
consideration to advection and dispersion in both the gaseous and aqueous phases
and includes irreversible first order reaction processes such as oxidation and
Comprehensive Range of Generalized Boundary Conditions
CTRAN/W supports a comprehensive list of
boundary condition options for gas and solute transport including
concentration, mass rate, mass flux, source concentration, and free exit mass
flux. In keeping with the entire GeoStudio suite, CTRAN/W makes broad use of
generalized functions for boundary condition definition.
CTRAN/W computes contaminant migration using these parameters and the advective-dispersive differential equation, derived by applying the principle of mass balance to an element of porous medium given advection, dispersion, adsorption, and decay. CTRAN/W computes adsorption using an adsorption function and the simulated nodal concentrations to determine the quantity of mass in both the fluid and solid phases.
Convenient Initial Condition Definition
The initial concentration for a transient
analysis can be defined using a variety of options including a region activation
concentration, spatial function, or by using the results from another CTRAN/W
Model in 1D, 2D, Axisymmetric or Plan View
CTRAN/W includes analysis options for
modelling pseudo three-dimensional problems.
Powerful Graphing of Results
Graphing is critical for the interpretation
of solute and gas transport analyses. The powerful graphing options in GeoStudio make it possible to plot critical
information in CTRAN/W such as the spatial distribution of concentration,
concentration verses time, mass fluxes, changes in mass within
the domain, cumulative mass discharge, and more. All of this data can be exported or copy/pasted directly
into spreadsheet software.
Sensitivity Analysis with CTRAN/W
A sensitivity analysis can be readily
conducted with CTRAN/W by cloning multiple analyses using the Analysis Tree and
then making slight changes to each one.
Integration with SEEP/W
CTRAN/W uses the results from a water
transfer analysis as computed by SEEP/W for advection-dispersion
modelling. Alternatively, CTRAN/W can be run simultaneously with SEEP/W to
analyse density-dependent water flow.