Thermal Simulation set up

[Anonymous]

I am trying to simulate a DIP component operating at 2W on a PCB inside an aluminum tube. The base flange of the tube has an applied heat of 100 C, but I am a bit confused on how I should model the DIP. The whole thing is intended to operate in a vacuum so the main mode of head transfer will be through radiation. Do I need to add a radiation load to the DIP as well as a heat source? I believe I need to add a radiation load to the inside of the tube as well, but do I need to add one to the outside to simulate heat leaving the system?

Thanks

[John_Holtz]

Hi @Anonymous

I do not fully understand the description regarding the radiation. The key is where is the radiation coming from and going to.

• If the radiation is coming from a surface of the model and going to the environment (or vice versa), you can simulate it with Fusion. The Radiation load that you apply to a surface is for heat exchanged with the environment.
• If the radiation is coming from a surface of the model and strikes another surface of the model, Fusion cannot handle that situation. It does not have "body to body" or "surface to surface" radiation.

In your situation, I can envision how heat would radiate from the chip to the internal DIP plate, conduct through the DIP plate, then radiate from the internal DIP plate to the inside of the tube, conduct through the tube wall, and then radiate from the outside of the tube to the environment. Only this last radiation transfer (outside of tube to environment) can be analyzed in Fusion. If you can ignore the internal body-to-body radiation and use conduction to dissipate the heat, then you can use Fusion for your analysis.