The Induction Heating Interface
The Induction Heating interface () is used to model induction heating and eddy current heating. This multiphysics interface adds a Magnetic Fields interface and a Heat Transfer in Solids interface. The multiphysics couplings add the electromagnetic power dissipation as a heat source, and the electromagnetic material properties can depend on the temperature.
Depending on the licensed products, stationary modeling and time-domain modeling are supported in 2D and 3D. In addition, combinations of frequency-domain modeling for the Magnetic Fields interface and stationary modeling for the Heat Transfer in Solids interface, called frequency-stationary and, similarly, frequency-transient modeling, are supported.
When a predefined Induction Heating interface is added from the Heat Transfer>Electromagnetic Heating branch () of the Model Wizard or Add Physics windows, Magnetic Fields and Heat Transfer in Solids interfaces are added to the Model Builder. A Multiphysics node is also added, which automatically includes the multiphysics coupling features Electromagnetic Heat Source, Boundary Electromagnetic Heat Source, and Temperature Coupling.
On the Constituent Physics Interfaces
The Magnetic Fields interface is used to compute magnetic field and induced current distributions in and around coils, conductors and magnets. Depending on the licensed products, stationary, frequency-domain, and time-domain formulations are supported in 2D and 3D. Note that the frequency and time domain formulations become ill-posed when approaching the static limit. One may extend the useful frequency range downward by adding a low electric conductivity. The Magnetic Fields interface solves Maxwell's equations formulated using the magnetic vector potential and, optionally for coils, the scalar electric potential as the dependent variables.
The Heat Transfer in Solids interface provides features for modeling heat transfer by conduction, convection, and radiation. A Heat Transfer in Solids model is active by default on all domains. All functionality for including other domain types, such as a fluid domain, is also available. The temperature equation defined in solid domains corresponds to the differential form of Fourier's law that may contain additional contributions like heat sources.
In previous versions of COMSOL Multiphysics, a specific physics interface called Induction Heating was added to the Model Builder. Now, a predefined multiphysics coupling approach is used, improving the flexibility and design options for your modeling. For specific details, see Multiphysics Modeling Approaches in the COMSOL Multiphysics Reference Manual.
Settings for Physics Interfaces and Coupling Features
When physics interfaces are added using the predefined couplings, for example Induction Heating, specific settings are included with the physics interfaces and the coupling features.
However, if physics interfaces are added one at a time, followed by the coupling features, these modified settings are not automatically included.
For example, if single Magnetic Fields and Heat Transfer in Solids interfaces are added, COMSOL adds an empty Multiphysics node. You can choose from the available coupling features but the modified settings are not included.
Coupling features are available from the context menu (right-click the Multiphysics node) or from the Physics toolbar, Multiphysics menu.
Table 7-1: Modified settings for an induction heating interface
Physics Interface or Coupling Feature
Modified Settings (if any)
Magnetic Fields
No changes.
Heat Transfer in Solids
No changes.
Electromagnetic Heat Source
The Domain Selection is the same as that of the participating physics interfaces.
The corresponding Magnetic Fields and Heat Transfer in Solids interfaces are preselected in the Electromagnetic Heat Source section.
Boundary Electromagnetic Heat Source
The Boundary Selection is the same as the exterior and interior boundaries of the Domain Selection of the participating physics interfaces.
The corresponding Magnetic Fields and Heat Transfer in Solids interfaces are preselected in the Boundary Electromagnetic Heat Source section.
Temperature Coupling
The corresponding Magnetic Fields and Heat Transfer in Solids interfaces are preselected in the Temperature Coupling section.
A side effect of adding physics interfaces one at a time is that two study types—Frequency-Stationary and Frequency-Transient—are not available for selection until after at least one coupling feature is added. In this case, it is better to first add an Empty Study, then add the coupling features to the Multiphysics node, and lastly, right-click the Study node to add the study steps as needed.
Physics Interfaces and Coupling Features
Use the online help in COMSOL Multiphysics to locate and search all the documentation. All these links also work directly in COMSOL Multiphysics when using the Help system.
Coupling Features
•
The Electromagnetic Heat Source coupling feature node is described in this section.
•
The Electromagnetic Heat Source and Temperature Coupling feature nodes are described for The Joule Heating Interface in the COMSOL Multiphysics Reference Manual.
Physics Interface Features
Physics nodes are available from the Physics ribbon toolbar (Windows users), Physics context menu (Mac or Linux users), or right-click to access the context menu (all users).
In general, to add a node, go to the Physics toolbar, no matter what operating system you are using. Subnodes are available by clicking the parent node and selecting it from the Attributes menu.
•
The available physics features for The Magnetic Fields Interface are listed in the section Domain, Boundary, Point, and Pair Nodes for the Magnetic Fields Interface.
•
See The Heat Transfer Interfaces in the COMSOL Multiphysics Reference Manual for information about the available physics features for heat transfer.
Inductive Heating of a Copper Cylinder: Application Library path ACDC_Module/Electromagnetic_Heating/inductive_heating
See The Heat Transfer Interfaces and The Joule Heating Interface in the COMSOL Multiphysics Reference Manual for other Heat Transfer interface and feature node settings.