Introduction
A Steady-State Thermal-Electric Conduction analysis allows for a simultaneous solution of thermal and electric fields. This coupled-field capability models joule heating for resistive materials and contact electric conductance as well as Seebeck, Peltier, and Thomson effects for thermoelectricity, as described below.
Joule heating - Heating occurs in a resistive conductor carrying an electric current. Joule heating is proportional to the square of the current, and is independent of the current direction. Joule heating is also present and accounted for at the contact interface between bodies in inverse proportion to the contact electric conductance properties. (Note however that the Joule Heat results object will not display contact joule heating values. Only solid body joule heating is represented).
Seebeck effect - A voltage (Seebeck EMF) is produced in a thermoelectric material by a temperature difference. The induced voltage is proportional to the temperature difference. The proportionality coefficient is known as the Seebeck Coefficient (α).
Peltier effect - Cooling or heating occurs at a junction of two dissimilar thermoelectric materials when an electric current flows through that junction. Peltier heat is proportional to the current, and changes sign if the current direction is reversed.
Thomson effect - Heat is absorbed or released in a non-uniformly heated thermoelectric material when electric current flows through it. Thomson heat is proportional to the current, and changes sign if the current direction is reversed.
Points to Remember
Electric loads may be applied to parts with electric properties and thermal loads may be applied to bodies with thermal properties. Parts with both physics properties can support both thermal and electric loads. See the Steady-State Thermal Analysis section and the Electric Analysis section of the help for more information about applicable loads, boundary conditions, and results types.
In addition to calculating the effects of steady thermal and electric loads on a system or component, a Steady-State Thermal-Electric analysis supports a multi-step solution.
Preparing the Analysis
Create Analysis System
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From the Toolbox, drag the Thermal-Electric template to the Project Schematic.
Define Engineering Data
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To have Thermal and/or Electrical effects properly applied to the parts of your model, you need to define the appropriate material properties. For a steady-state analysis, the electrical property Resistivity is required for Joule Heating effects and Thermal Conductivity for thermal conduction effects. Seebeck/Peltier/Thomson effects require you to define the Seebeck Coefficient material property.
Attach Geometry
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Note that 3D shell bodies and line bodies are not supported in a thermal-electric analysis.
Define Part Behavior
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Mechanical does not support Rigid Bodies in thermal-electric analyses. For more information, see the Stiffness Behavior documentation for Rigid Bodies.
Define Connections
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Contact across parts during a thermal-electric analysis consider thermal and/or electric effects based on the material properties of adjacent parts. That is, if both parts have thermal properties, thermal contact is applied and if both parts have electric properties, electric contact is applied.
Apply Mesh Controls/Preview Mesh
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There are no specific considerations regarding meshing for a thermal-electric analysis.
Establish Analysis Settings
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For a Thermal-Electric analysis, the basic Analysis Settings include:
- Step Controls for Static and Transient Analyses
: used to specify the end time of a step in a single or multiple step analysis. Multiple steps are needed if you want to change load values, the solution settings, or the solution output frequency over specific steps. Typically you do not need to change the default values.
- Nonlinear Controls
Typical thermal-electric problems contain temperature dependent material properties and are therefore nonlinear. Nonlinear Controls for both thermal and electrical effects are available and include Heat and Temperature convergence for thermal effects and Voltage and Current convergence for electric effects.
- Output Controls
Output Controls enable you to specify the time points at which results should be available for postprocessing. A multi-step analysis involves calculating solutions at several time points in the load history. However you may not be interested in all of the possible results items and writing all the results can make the result file size unwieldy. You can restrict the amount of output by requesting results only at certain time points or limit the results that go onto the results file at each time point.
- Analysis Data Management
Review these settings as needed.
- Solver Controls
The default Solver Controls setting for thermal-electric analysis is the Direct (Sparse) solver. The Iterative (PCG) solver may be selected as an alternative solver. If Seebeck effects are included, the solver is automatically set to Direct.
Define Initial Conditions
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There is no initial condition specification for a thermal-electric analysis.
Apply Boundary Conditions
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The following loads are supported in a Thermal-Electric analysis:
Solve
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The Solution Information object provides some tools to monitor solution progress.
Solution Output continuously updates any listing output from the solver and provides valuable information on the behavior of the model during the analysis. Any convergence data output in this printout can be graphically displayed as explained in the Solution Information section.
Review Results
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Applicable results include all thermal and electric results.
Once a solution is available, you can contour the results or animate the results to review the responses of the model.
For the results of a multi-step analysis that has a solution at several time points, you can use probes to display variations of a result item over the steps.
You may also wish to use the Charts feature to plot multiple result quantities against time (steps). For example, you could compare current and joule heating. Charts can also be useful when comparing the results between two analysis branches of the same model.