I'm currently trying to run a simulation on a heatsink design that I'm working on. It's an LED fixture that has a central heatsink, with the LEDs mounted in small pods remotely from the main heatsink, thermally connected via heat pipes. I currently have an internal flow simulation set up seemingly correctly, and I can see all the information I want when it comes to areas inside the fluid domain. That is only a small portion of the overall design, and is limited to the central heatsink itself.

What I want to see is the actual LED temperatures. These features are outside of the fluid domain (still inside the computational domain), and no matter what kind of plot I set up, or goals defined (like max solid temperature on each MCPCB for the LEDs), I can't actually see any plot outside of the fluid domain.

I've tried an external flow simulation too, and while I can see the thermal data for the whole assembly, it doesn't take into account the flow conditions internal to the heatsink. I've tried adding a fluid subdomain for that, but I didn't get any different result.

I'm a newcomer to fluid simulation, so I'm sure there is some simple step to getting this done, but for the life of me, I can't seem to figure it out. All of the tutorials I've found so far only deal with electronics assemblies inside an enclosure, effectively making the computational domain and the fluid domain the same, which doesn't help in my situation.  The only thought I had was to create a "room" that would have an inlet (tied directly to the fan opening) and an outlet (effectively venting to ambient) and running it as an internal simulation.

Anyway, any help that can be given would be greatly appreciated.

Thanks in advance.