Heating Source
 

I have an electric resistance heater. First of all, I simply approximated this as an imprinted heat output. Unfortunately, I have found that there is probably a temperature dependency that cannot be neglected. Is there a simple way of making the impressed power dependent on the temperature?
I am currently using a subdomain with a heat source as a heater.

regards
Frank

Sure. Just make volumetric heat a function of temperature using the CFX expression language or a user function:
VolHeatExample = 100[W/m^3] + 5[W/m^3/K]*T.
You could also use an electric model, and have variable electrical resistance, and define a current or voltage on the conductor ends (see tutorials).

Thanks for the tip. I also came up with this type of solution yesterday. I wanted to avoid the electric model because of the effort involved.