Heat sources

Heat sources can be used to simulate heat generation from a volume. For instance, it is useful when dealing with electronic equipment and HVAC systems, to model heat generated by chips on a circuit board, or by car engines in a garage.


SimScale currently supports heat sources in Convective heat transfer and Conjugate heat transfer. In both cases, the heat source has to be assigned to a volume which can be one of the following:

  • A geometry primitive (cartesian box, sphere, cylinder).
  • A cell zone, which can be created during the hex-dominant parametric meshing operation (see the Surface Refinement section of Mesh settings for further details on creating a cell zone). The advantage of this option, with respect to the geometry primitive, is that an arbitrary shape can be set as heat source.
  • The whole region, or any solid of a multi-region mesh (see the page Creating multi-region mesh for the related meshing tutorial).

Creation of a heat source

In the simulation tree, navigate to “Advanced Concepts” and add a Heat Source. Two types of heat sources are supported:

Heat Source

This type of source has to be used when the total power emitted by the heating element is known. The user is required to provide this value and to choose the relevant region of the domain.

Volumetric heat source

This type of source has to be used when the power density is known. This is simply total power per unit volume. This quantity is often provided for batteries and fuel cells, for example.


In both cases, when the user applies a single heat source to multiple entities, each of them produces the prescribed power value. For instance, if you create a power source with a value of 100 Watt and assign it to two entities, say A and B, A will emit 100 Watt, and B will also emit 100 Watt.

Defining a heat source (Geometry primitive)

In the figure above, a heat source is defined in a Convective heat simulation. The geometry primitive is shown in blue, inside the domain. A value of 10W is assigned to it.

Defining a heat source (Multi-region mesh)

In the second figure, a heat source is defined in a Conjugate heat transfer simulation. Here it is possible to set one of the solids as a heat source. One can either select the solid in the viewer, switching to the volume selection mode, or use the check box on the top-right corner of the screen.

All simulations are contained in this project:

Heat sources reference project