Use this subnode to specify the harmonic variation of a prescribed temperature value. It is used only in a study step of type Frequency-Domain Perturbation.

Enter a value or expression for the Temperature perturbation ΔT0 to be added to the equilibrium temperature T0 defined in the parent node.

More locations are available. For example:
Heat Transfer in Solids>Thin Rod>Temperature>Harmonic Perturbation
Heat Transfer in Solids>Thin Layer>Temperature>Harmonic Perturbation
Heat Transfer in Solids>Thin Film>Temperature>Harmonic Perturbation
Heat Transfer in Solids>Fracture>Temperature>Harmonic Perturbation
Heat Transfer in Solids>Thin Layer>External Temperature>Harmonic Perturbation
Heat Transfer in Thin Shells>Temperature>Harmonic Perturbation

Physics Tab with Temperature or External Temperature selected in the model tree:
Attributes>Harmonic Perturbation