wobbl thermal
thermal answers whether a part overheats, at steady state or over a given time.
$ wobbl thermal PART -m MATERIAL [--power P] [--film FILM] [options]Examples
# a 15 W chip on a heat sink in a 40 C cabinet, at steady state$ wobbl thermal heatsink.py -m 6063-t5 --power "15 W" \ --heat-faces "bottom and box 17.5,17.5,-1,42.5,42.5,0.5" \ --film "6 W/m2K @ all" --ambient "40 C" --radiation 0.85 --limit "85 C" # a battery pack in a sealed box over a one hour discharge$ wobbl thermal pack.py -m li-ion-cell --power "6 W" --film "5 W/m2K @ all" \ --ambient "35 C" --radiation 0.9 --duration "60 min" --limit "60 C"Options
| Option | What it does |
|---|---|
-m, --material |
the material, which is required here and sets conductivity, density and specific heat |
-p, --power |
heat made inside the part, such as "12 W", spread evenly through the volume |
--heat-faces |
puts the power on these faces instead, such as the patch a chip touches |
--film |
convection, repeatable, such as "5 W/m2K @ all" or "25 W/m2K at 30 C @ top" |
--ambient |
the air temperature, 25 C by default |
--fixed-temp |
a held temperature, repeatable, such as "40 C @ bottom" |
--duration |
the length of a transient run, such as "30 min", and without it the run is steady state |
--limit |
the temperature limit, by default the material’s service limit |
--radiation |
the surface emissivity, such as 0.9 for painted or plastic surfaces, and 0 (the default) turns radiation off |
--quality |
fast or normal (the default) |
--question |
the question this run answers, shown in the report |
-o, --out |
the result folder, by default wobbl-out/<part> |
--json |
prints the result as JSON |
Without any --film, Wobbl assumes open air at 10 W/(m2 K) on every face, and radiation acts
on the same faces as the films. The verdict is ok, warm within 5 C of the limit, or hot past
it, and a transient run also says when the limit is crossed. Heat
has typical film values and how heat answers are checked.