For the conjugate heat transfer problem (computer enclosure) in the tutorial, the enclosure material is the project stainless steel 321, heat sink is aluminum, lids are insulators, motherboard is “Tutorial PCB”, chip is “Tutorial component package”.
Disparate material cannot have perfect contact and there are always thermal contact resistances. However, so far in the tutorial there has been no dialog showing how to specify contact thermal resistance.
But does it actually exist even if we don’t specify? What is the default value?