First, let me say that I'm not a physics or engineering student looking for an easy answer. I'm an idiot looking for an easy answer.
If I have an aluminum tube with cool air flowing through it, what is the best scenario to mitigate heat transfer from the outside air?
Inside/outside polished?
Inside/outside black?
Inside black, outside polished?
Inside polished, outside black?
Thanks
If I have an aluminum tube with cool air flowing through it, what is the best scenario to mitigate heat transfer from the outside air?
Inside/outside polished?
Inside/outside black?
Inside black, outside polished?
Inside polished, outside black?
Thanks
wrap it in insulation? - “super insulation” combines convection blocking with layers of low emissivity reflective foils
the radiative coupling to air only occurs where the air is opaque to the radiation wavelengths
you are more often radiatively coupled to other opaque materials in the field of view of the radiating surface – can be clouds, cloudy nights are warmer than clear – you can freeze water by radiative cooling in clear dry high desert summer nights
the radiative coupling to air only occurs where the air is opaque to the radiation wavelengths
you are more often radiatively coupled to other opaque materials in the field of view of the radiating surface – can be clouds, cloudy nights are warmer than clear – you can freeze water by radiative cooling in clear dry high desert summer nights
Thems big words there! If you meen heat trasnsfer though:
An unpolished surface has more surface area, therefore more heat transfer, negligible though. If the heatsink is in the dark, it does not care what colour it is. I have not done any tests, but I would assume that anodized aluminium would have a lower rate of heat transfer than natural alu. E
An unpolished surface has more surface area, therefore more heat transfer, negligible though. If the heatsink is in the dark, it does not care what colour it is. I have not done any tests, but I would assume that anodized aluminium would have a lower rate of heat transfer than natural alu. E
If your concern is heat transfer from the outside air, as you say, then insulation is the answer; polishing will make little difference because air is not a good radiator or absorber of heat. If it is heat transfer from nearby (radiating) objects then polishing is the answer, although appropriate insulation will work too.
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