5 Replies Latest reply on May 18, 2018 1:03 PM by Anthony Castellano

    Thermal conductivity during thermal study

    Anthony Castellano

      Hi all,

       

      I am doing a simple reality check so that I can trust the thermal simulations. I am running into a situation I don't fully understand.

       

      Setup:

      I have two platforms, with a connection by a wire. The top one has a fixed temperature, the bottom one dissipates heat at a fixed rate. When I run the thermal simulation, it shows the temperature distribution of the two platform, with a rainbow along the wire. I am interested in the steady-state temperature of the bottom platform.

       

      Here's the part that's confusing me: When I change the thermal conductivity of the wire (all the way from one billion to one billionth), the steady-state temperature of the bottom platform never changes. According to my physical intuition, the more conductive the wire, the faster heat will travel to the lower platform. Since the lower platform dissipates heat at a constant rate, heat traveling fast into the platform might overwhelm the heat dissipation, causing the steady-state temperature to rise.

       

      I want to know if my physical intuition is wrong, or if there's something with the program that I need to fix. I'll attach my simulation.

       

      Thanks 10^6,

      Tony

        • Re: Thermal conductivity during thermal study
          Ryan Dark

          Hi Tony,

          This is an interesting question.  Yes, if you have a set temperature on one side, a negative heat power sucking out power on the other side, and different conductivity wires between I might expect that the temperature values would be different.  I made a mock model and did this and the values despite being nonsensical (negative Kelvin values) did change.  The temperature coloration did remain the same because the extents of the legend changed to accommodate the different temperature values but the difference is there.  There is a large pooling of heat on the temperature side and a large "vacuum" of heat on the other side.

           

          Rubber Wire:

           

          Plain Carbon Steel Wire:

          • Re: Thermal conductivity during thermal study
            Anthony Castellano

            If I edit the material in the assembly file, then the results of the thermal study are unaffected, but if I edit the material in the part file, then the results are affected.

             

            Further, the edits during the assembly have an effect, since the saved values appear during the edit of the part file.

             

            Does anybody have any idea how this is going on? I'm finding the right thermal conductivity through trial and error, and it would be nice if I didn't have to click back and forth between all these files.

             

            Thanks,

            Tony