Emissivity coefficient of aluminum black-anodized surface on ambient temperature 1

[MEngr3239]

The emissivity coefficient of aluminum anodized is 0.77 as shown in the attachment. However, as applied the provided value to a thermal simulation case in SolidWorks, it seems 0.77 is way higher so that the simulated results for its surface temperature are very low compared to the real lab testing results. Has anyone out there experienced the same as described above? Can someone please justify whether the value 0.77 for an anodized AL surface is dependable that can be applied to the thermal simulation cases? Can you please provide the emissivity coefficient of anodized aluminum that is verified in the real world? Thank you in advance.

 

[georgeverghese]

Ok, I see more background material in the earlier post.
Emissivity of 0.8 should be okay for anodised aluminum 5052 at room temps

Thermal conductivity:
Since the oxide layer in anodised aluminum is presumably very thin, it is okay to ignore anodised treatment and use the thermal conductivity of plain aluminum 5052 for the 0.05in thick surface cover. This approach is okay since the thermal conductivity for most aluminum grades is relatively high anyway in comparison to that of the thermal pad. You could even ignore this aluminum plate resistance layer if you wish and apply the thermal resistance of the thermal pad only.

 

[MisterE2]

Its probably not a great idea to look up and plug in an emissivity coefficient for "anodized aluminum" you'll be faced with the question later on of "ah, anodized (our color or material) aluminum?" just grab your thermal camera and thermocouple and do it manually with a heat gun on the cool down, crude but actually pretty effective.