I'm extremely new to Autodesk CFD, and I'm working on a project that deals with diodes heating up and cooling down based on a fixed temperature regulated by a temperature switch. Basically, I have a string of 6 diodes soldered together hooked up to a temperature switch, and when the diode temperature reaches 150C, the current stops flowing through the diodes. Another parameter is that this diode chain is immersed in an aluminum bottle of oil, so convection currents come into play. My problem is, I'm trying to model this on Autodesk CFD, and I'm not really sure how to go about modeling something that is fluctuating in temperature, AND has convection currents surrounding it.
The natural convection of the oil shouldn't be an issue and can be solved without any 'assumptions' to be made. The challenge comes with the diodes temperature control. CFD doesn't currently have a temperature controlled heat flux, so some assumptions will have to be made. The simplest assumption would be to just assign a temperature of 150C and assume it is always running at the hottest. This would assume that the diodes do not cool down much before current is passed back through again. If we assume this fixed temperature then the analysis is a simple steady state and the setup can follow the guide in the help: http://help.autodesk.com/view/SCDSE/2019/ENU/?guid=GUID-A7E7C4B9-701B-4A4E-9F98-2E7C0BD1CB31
We can get more complicated than that (transient, fixed volume of oil), but I would recommend taking your question to the Autodesk CFD forums.