Divergence in symmetrical thermal model in Workbench
I hope I am right here and you can help me with my problem
I guess, the basic problem is rather hard to describe, but I'll try it anyways:
For a project I want to simulate the thermal behavior of a heat sink. The model consists of a chip, that emits a constant heat flux, a heat sink made from copper and the surrounding air. Since the chip and the the heat sink are both symmetrical, I wanted to simulate only one quarter of the problem.
So what I did was, that I modeled one quarter of the chip and one quarter of the air. Afterwards I applied the loading conditions, which is the constant heat flux. To make things easier, I set the conductivity at the contact area to a constant value (to simulate an easy convection) and the temperature at the outer shell of my air as a constant value.
Afterwards I simulated the whole thing for the element sizes 15, 20 and 25 mm for the heat sink and 120 mm for the air. For the contact size, I always chose the size of the elements of the heat sink.
Now comes the part that I don't understand: For some reason, the temperature diverges, when I refine the elements, and I really can't think of a reason why. Is there something wrong with my mesh, or the mesh that is created by Workbench? If I simulate half the chip, I get converging temperatures.
I attached a screenshot of the heat sink for a better understanding
I hope you can give me a tip, where my problem might be. Thanks in advance!