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 Heat Source node adds a source term Q to the right-hand side of the heat equation:
Specify Q0 as the heat rate per unit volume, as a linear heat source, or as a heat rate.
Material Type
Select an option in the Material type list to specify if the inputs of the Heat Source section are defined in the material or spatial frame:
The default option for the Heat Source node is Solid, which specifies that the heat source Q0 is defined in the material frame. Because the heat transfer variables and equations are defined in the spatial frame, the inputs are internally converted to the spatial frame. See Conversion Between Material and Spatial Frames for details.
The Nonsolid option defines Q0 in the spatial frame. No frame conversion is needed.
The From material option uses the option selected in the Material type list of the Material Properties section of the material applied on the domain on which the node is active.
Heat Source
Click the General source (the default), Linear source, or Heat rate buttons.
For General source enter a value for the distributed heat source Q0 when the default option (User defined) is selected. See also Additional General Source Options to use predefined heat sources available from other interfaces.
For Linear source enter a value for the Production/absorption coefficient 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.
For Heat rate enter a value for the heat rate P0. In this case Q0 = P0V, 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 User defined 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:
With the addition of an Electric Currents interface, the Total power dissipation density (ec) heat source is available from the General source list.
With the addition of any version of the Electromagnetic Waves interface (which requires the RF Module), the Total power dissipation density (emw) and Electromagnetic power loss density (emw) heat sources are available from the General source list.
With the addition of a Magnetic Fields interface (a 3D component requires the AC/DC Module), the Electromagnetic heating (mf) heat source is available from the General source list.
With the addition of a Magnetic and Electric Fields interface (which requires the AC/DC Module), the Electromagnetic heating (mef) heat source is available from the General source list.
Stabilization Techniques in the COMSOL Multiphysics Reference Manual
Forced Convection Cooling of an Enclosure with Fan and Grille: Application Library path Heat_Transfer_Module/Power_Electronics_and_Electronic_Cooling/electronic_enclosure_cooling
Location in User Interface
Context Menus
Ribbon
Physics Tab with interface as Heat Transfer in Solids and Fluids, Heat Transfer in Solids, Heat Transfer in Fluids, Heat Transfer in Porous Media, Heat Transfer in Building Materials or Bioheat Transfer selected: