WOBBLheatsink.py

Will a 15 W chip stay under 85 C on this heat sink without a fan?

Heat report
2026-10-13 10:49
OK

Hottest point reaches 70.3 C (limit 85 C) at (30, 29.9, 0) mm at steady state.

max temperature
70.3 C
limit
85 C
power
15 W
mesh nodes
137,258

Confidence high

  • passed mesh convergence, energy balance, hand calculation, units and sanity
Temperature with the hottest point marked
Temperature with the hottest point marked

Checks

statuscheckresult
passmesh convergencetemperature rise at the hottest point settled: 30.3 -> 30.2 -> 30.3 C over 3 meshes, last change 0.2%
passenergy balanceheat in 15 W, heat out through the surfaces 15 W (3.1e-07% apart)
passhand calculationheat balance on a uniform skin gives 68.1 C; the FEA skin averages 68.1 C (0.0029% of the rise). Biot 3.1e-05: the part is nearly isothermal
passunits and sanitytemperatures between 67.1 and 70.3 C

Assumptions

  1. Aluminum 6063-T5: conductivity 209 W/(m K), specific heat 900 J/(kg K), density 2700 kg/m3.
  2. Heat enters through bottom and box 17.5,17.5,-1,42.5,42.5,0.5.
  3. Convection uses a fixed film coefficient; real coefficients vary with temperature and airflow.
  4. Surrounding air or coolant at 40 C does not heat up.
  5. Radiation with emissivity 0.85.
  6. Contact resistance between parts and internal airflow are not modeled.