1 Reply Latest reply on Aug 23, 2016 10:20 AM by Jay Seaglar

    Thermal Simulation with hotter and colder temperatures than boundary conditions - suggested Solutions didnt work

    Andreas Lunzer

      I have a question regarding thermal simulation. First of all - I tried to duplicate the study from a steady state study and copy the mash with the same result and already looked for answers. I realized some people have the same problem, but I didn't find a solution

       

      I am simulation a cooled metal block, in which a hot object cools down in a hole. I chose the body for the initial temperature from the tree menu and for the constant temperature i chose the surface of the "cooling tunnel" an set it to 21°C.

       

      My hot part was set to initial 200°C

      The metal part was set to initial 25°C

      and the cooling tunnel so a constant temperature of 21°C

       

      I let it cool for 8 sec and experienced at the beginning weird results. Ranging from negative temperatures to higher temperatures than 200°C.


      So i simplified it an those mistakes occur on the touching surfaces of 2 blocks. One block is 25°C and the other one is 200°C at the beginning.

       

       

      as a result i get a not as dramatic but similar result of non logical temperatures.

      Simplified Heat Problem.PNG

      if i increase the time-step my coolest temperature drops under 20°C.

       

      I reduced the mesh size and time steps with no success.

       

      I guess the problem in my more complex part is similar to this one

       

      I appreciate any help and ideas!


      Greetings