3 Replies Latest reply on Oct 15, 2014 6:10 PM by Jared Conway

    Thermal steady state study ignoring heat power

    Benjamin Teinby

      Hi guys,

      I am sitting with a steady state thermal analysis of a (rather complex) part made of aluminum.

       

      The overall goal is to do a thermal expansion analysis in a static study afterwards, to see how key positions on the part moves, when it is fixated with bolts in all four corners, and heat is applied.

       

      The aluminum part is placed on top of a flat 10 mm thick steel plate.

       

      My problem is that when I set the 10 mm thick plate to a temperature of 20 degrees Celsius and apply 40 W of heat power to a surface on the alu part and 2 W of cooling to another surface, it seems to ignore the heat power. When I run the simulation it simply turns both parts the same color, indicating it to be 23 degrees Celsius. There is no problem when running the simulation with the alu part only, here it shows a temperature gradient as it should.

       

      I have tried just about anything, including setting the thermal resistance, reversing the direction of the heat power, re-assembly it with new “mates” and moving the thermal loads around on the parts.

       

      I know it might be difficult to help me out without taking a look at the model yourselves, but due to confidentiality I cannot show it.

       

      I can however show the simulation tree.

       

      To SolidWorks forum.PNG

       

      I am quite new to SolidWorks and hoped it would be as easy to use as other CAD software.

       

       

      If anyone have the slightest idea of how to fix this, I will really appreciate it.

        • Re: Thermal steady state study ignoring heat power
          Jared Conway

          what is the physical interpretation of the boundary conditions?

           

          are some faces really always 20deg C?

           

          you say "There is no problem when running the simulation with the alu part only" > so what is the difference between the study that works and the one that doesn't work?

           

          are the parts touching? (does interference detection with treat coincidence as interference find the faces that are touching?)

           

          to me your problem is somewhat underdefined, 40W = 2W and the 20deg C could rest on either side of the equation

           

          i would recommend posting the models or sample files if you can't post those

            • Re: Thermal steady state study ignoring heat power
              Benjamin Teinby

              The steel plate is kept at a constant temperature by active cooling, so yes some of the faces are 20deg C.

              The difference between the simulations are, that this one is on an assembly of the alu and steel part and not just the alu part alone.

               

              The parts are touching but not interfering (I just checked)

              I am trying to model a laser which applies approx. 40 W into the alu part, while a peltier-element is cooling another spot on the alu part down by approx. 2 W. The whole alu part is sitting on a steel plate which is being cooled down to approx 20 deg C.

               

              By under defined, do you mean that I am missing something to balance out the 40 W or that I should define the system clearer? So that the 20 deg C is on "the other side of 40 W" in the equation.

               

              Unfortunately I cannot show the model, even though it would make it a lot easier.

               

              I realise it would not be possible for anyone to help out without seeing the model, but any attempt will be appreciated.