Help with Thermal Analysis

jutermohle · ‎Nov 01, 2016

I am trying to simulate a thermal analysis for heating a housing on a conduction hot plate sitting out in ambient air. This is to complete a transient thermal analysis for the minimum or maximum temperature with time. I want to just run the analysis on the model of the housing with the conditions that it has conduction heat transfer on one surface and convection heat transfer on the other surfaces. I am not sure if I should try to use a heat load or prescribed temperature for the conduction heat transfer. Is there a way to equate the heat load in Watts for the conduction heat transfer from the hot plate to the housing? Or should I try to set a prescribed temperature for the hot plate where it contacts the housing? Any suggestions on how to go about completing the analysis would be greatly appreciated.

JonathanHodgson · ‎Nov 10, 2016

What is the thermal mass of the hotplate, compared to the housing? If it's large, then I'd suggest prescribed temperature; if it's small, then a heat load.

Really though, if you're doing a transient analysis, surely you should include the hotplate in the model... Does it start from cold, or is the hotplate preheated before you put the housing on it?

jutermohle · ‎Nov 10, 2016

I'm not sure what the thermal mass of the hot plate is. Only the temperature of its surface that is in contact with the housing. The hot plate is already heated to a temperature of approximately 260 degrees Celsius then the housing is placed on it with the housing at room temperature. The diameter of the hot plate is 8 inches and the circular housing that sits on it has a diameter of approximately 6.9 inches. I did not consider trying to run the thermal analysis on an assembly. So I tried to do this. I made a circular disk to simulate the hot plate. I set a prescribed temperature of the hot plate to be 260 degrees Celsius. I also placed an approximate convection condition of the ambient air around the housing. When I try to run the analysis it tells me that the prescribes temperatures in the constraint set and the initial temperature must be the same value. So now I am not sure what it means or how to eliminate this error.

The analysis I would like to run is with a circular hot plate with the given dimension to be already heated to a temperature of 260 degrees Celsius when the analysis starts and maintained at this temperature during the analysis. With a circular housing sitting on top of it with the given dimension starting at an initial temperature of 25 degrees Celsius. I can approximate the surrounding ambient air temperature around the housing if this boundary condition is needed. Is there any recommendations on how to run this analysis.

All I am trying to do is heat a housing on a hot plate. Hot plate set and maintained at a temperature. The housing starts at room temperature. Then a transient analysis to determine the minimum and maximum temperatures in the housing with time. How do I do this in PTC Simulate?

hrichter · ‎Mar 06, 2017

I hope you have found a solution to your problem by now

If I were you, I'd try around a bit. Set to prescribed temperature first, then you can try with a higher or lower temperature. It's important that you use the right equipment though, so if you're not getting the results you're looking for, I'd look into the equipment? There aren't many manufacturers for thermal analysis but you can look at other specialists like Linseis for example.

Good luck.