'ResistorAssydraft' simulation project by kturnbull


#1

I created a new simulation project called 'ResistorAssydraft':

thermal analysis of assy


More of my public projects can be found here.


#2

Important: Help required
Hi . As you can probably tell I am new to thermal simulation!. Please could someone advise where Im going wrong
Aim: I am attempting to simulating three power resistors and their heat dissipation, looking at the temperature at the simulated thermal fuse (simplified as a strip). I have got errors but final run gave an output but doesn’t appear correct.
Question: Am I using the correct simulation setup.

Model origins: freecad
setup method as per :tutorial Thermal analysis of a differential casing
Information available : power (W) dissipated by the resistors


#3

Hi @kturnbull, I see one main problem: you forgot to add contact between the different connected parts. Without a contact definition there will be no heat transferred between different solids. It looks like there are quite a few solids intersecting. So first of all I would cut out all those intersections to be able to properly define contacts between the parts.

Additionally and especially if you are a beginner if thermal simulation, you can search the public projects for successful similar projects. I would for example recommend PCB - transient thermal analysis from @ahmedhussain18. This looks quite simular to your problem and also uses an assembly of multiple solids with thermal contacts between them.

Best,
Richard


#4

Hi @rszoeke thanks for reply. I must confess the model is crude. I expected to see the majority of heat transfer via convection from the resistor to the fuse. Will I have to remodel the assy IN FREECAD or can I make changes to simscale to determine convection? I just want to see the temperature at the fuse under various load conditions . I am looking into a serious safety situation potentially involving this component affecting innocent families (potentially 1million people) and really need someone to assist with the modelling.
The aim is to see if the temperature at the fuse is sufficient to melt solder 180-200deg C at one end and operate the fuse in three different load current scenarios. I am not convinced the design of the part thermally speaking will trip every time as required .