I have a transient thermal model of a PCB with intitial temperature at 50 Celcius.
There are 43 chips on the PCB; each contributing 9 watts.
But after running the model, it showed some negative temperatures on the PCB?
What could I be doing wrong?
Brent
I know this is old, but I had to puzzle this out today. Remember to set all bodies to an initial temperature as a separate condition or it will default to ab zero or some such. Setting bulk temp in convecton alone is not enough. Otherwise it will drive all the results to approach the default init temp of zero Kelvin.
I've seen this happen when the mesh is not sufficient to capture the geometry. You can show the global min & max locations to possible indicate the area where the problem lies. You'd want to create a surface plot of the mesh and turn off the option to "Use CAD geometry," so this will reveal for you the true computational mesh.