Heat Source

This node describes heat generation within the domain. You express heating and cooling with positive and negative values, respectively. Add one or more nodes as needed — all heat sources within a domain contribute to the total heat source.

The node adds a source term Q to the right-hand side of the heat equation:

Specify Q0 as the heat per unit volume, as a linear heat source, or as a heat rate.

Heat Source

Click the (the default), , or buttons.

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For enter a value for the distributed heat source Q0 when the default option () is selected. See also Additional General Source Options to use predefined heat sources available from other interfaces.

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For enter a value for the qs used in the predefined linear expression. The advantage of writing the source on this form is that it can be accounted for in the streamline diffusion stabilization. The stabilization applies when qs is independent of the temperature, but some stability can be gained as long as qs is only weakly dependent on the temperature.

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For enter a value for the heat rate P0. In this case Q0 = P0 ⁄ V, where V is the total volume of the selected domains.

Additional General Source Options

For the general heat source Q0 there are predefined heat sources available (in addition to a heat source) when simulating heat transfer together with electrical or electromagnetic interfaces. Such sources represent, for example, ohmic heating and induction heating. Depending on additional physics interfaces, the following are available:

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With the addition of an Electric Currents interface, the heat source is available from the list.

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With the addition of any version of the Electromagnetic Waves interface (which requires the RF Module), the and heat sources are available from the list.

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With the addition of a Magnetic Fields interface (a 3D component requires the AC/DC Module), the heat source is available from the list.

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With the addition of a Magnetic and Electric Fields interface (which requires the AC/DC Module), the heat source is available from the list.

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For the Heat Transfer in Porous Media interface, with the addition of interfaces from the Batteries & Fuel Cells Module, Corrosion Module, or Electrodeposition Module, heat sources from the electrochemical current distribution interfaces are available.

Frame Selection

To display this section, add both a and a interface (found under the branch when adding a physics interface). Then click the button (

) and select .

When the model contains a moving mesh, the check box is selected by default in the Heat Transfer interface, which in turn enables further options. Use to select the frame where the input variables are defined. If is selected, the variables take their values from the text fields. If (the default) is selected, a conversion from the material to the spatial frame is applied to the text field values

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Handling Frames in Heat Transfer

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Stabilization Techniques in the COMSOL Multiphysics Reference Manual


	You can specify the source to be a harmonic perturbation in a frequency domain analysis. To mark the source as being a harmonic perturbation, right-click the node and choose Harmonic Perturbation. Note that this updates the node’s icon. See Theory for Harmonic Heat Transfer for more details.


	For the definition of a localized heat source, see Line Heat Source, Line Heat Source and Point Heat Source. For the definition of a heat on a boundary, see Boundary Heat Source.


	Forced Convection Cooling of an Enclosure with Fan and Grille: Application Library path Heat_Transfer_Module/Power_Electronics_and_Electronic_Cooling/electronic_enclosure_cooling


	For a detailed overview of the functionality available in each product, visit http://www.comsol.com/products/specifications/

Location in User Interface

Context menus

Ribbon

Physics Tab with interface as , , , , , , or selected:
interface