Thermal Analysis Overview

In RS2 you can perform true thermal analysis of geotechnical structures that involve thermal behaviours. The various applications include ground stability using artificial ground freezing technique, thermal design for geostructures using insulation to prevent soil freezing or using thermosyphon to prevent soil thawing, effects of seasonal changes on the regional water flow, effects of temperature changes to the geotechnical design due to thermal expansion/contraction, etc.

To apply thermal analysis in RS2, follow the steps below:

1. In RS2 modeler, enable the Thermal Analysis under the Thermal page in the Project Setting menu. Choose a Thermal Method, and define correspondent settings:
   • Static Temperature
   • Steady Thermal FEA
   • Transient Thermal FEA
2. Make sure the Stages are defined, including Stage Name, Stage Time, and Stage Method (if applicable) in the Project Setting menu.
3. The material Thermal Properties can then be defined from the Properties menu. The thermal properties are determined by the combination of groundwater and thermal settings. Essential thermal properties of material include:
   1. Model Initial Temperature Condition
   2. Water content
   3. Thermal conductivity
   4. Heat capacity
   5. Thermal soil unfrozen water content
   6. Thermal Expansion
   7. Dispersivity
4. The liner thermal properties can also be defined from the Properties menu.
5. Switch to the Thermal flow tab , the Temperature Grid and Heat Transfer Section can be defined.
6. The Thermal Boundary Conditions can be defined from the Thermal menu. Available Thermal Boundary Conditions in RS2 include the followings:
   1. Temperature
   2. Nodal flux
   3. Flux
   4. Convection
   5. Insulation
   6. Thermosyphon
   7. Free
7. A History Query can be applied to monitor the thermal change of a specific location within the geometry throughout the analysis.

After computation, the thermal results can be viewed in RS2 Interpret in several means:

• Thermal Contours of the model geometry can be viewed and plotted.
• If the thermal behaviour havs been defined for a liner, the liner temperature can be plotted.
• One or more Thermal Flow Lines can be added.
• The thermal data of a history query, if ever defined, can be plotted.

For additional information about RS2 Thermal Analysis, see the following resources:

RS2 Thermal Analysis Theory Manual

RS2 Thermal Analysis Verification Manual

RS2 Thermal Analysis Example Manual

RS2 Thermal Analysis Tutorial: Effects of Thermosyphon on Shallow Foundation