I beg to differ.
Black is far more absorptive than white. But the emissivity is little
different between the two colours; in other words, if heat is being LOST by
radiation, then black is only marginally more efficient than white. Of
course "radiators" transfer heat mostly by conduction, which is not affected
by colour.
Duncan McF.
----- Original Message -----
From: "Fred Fillinger" <n3eu@comcast.net>
Subject: Re: Europa-List: black body radioation
>
>> I was wondering whether white paint would massively affect
> the ability of
>> the radiators to dissipate heat. My gut feeling tells me
> that the bypassing
>> air molecule does not mind the color of the hot metal bit
> it gets heated up
>> by. But then again ... there was something in science
> class many years ago
>> about dark body radiation.
>> ....
>> Please advise.
>>
>> <Thomas, N81EU>
>>
>
> You want black, not white. Quantum theory, Kichoff's laws,
> good absorbers (black) are good radiators (shedding heat of
> the hot fluid). But with tradeoff as your radiators will be
> absorbs the sun's heat in a given flight condition.
>
> But as a practical matter, you'd have to dip them in paint,
> I don't think we want to do that. So anything shot on just
> the front shouldn't matter. Black will disguise the fact of
> radiators there viewed from a distance. White would look
> odd to me on such a device. Gold might look like it was
> anodized the way a popular aircraft part comes. Silver
> metallic phony; we homebuilders use too much of that.
> Office beige? Whorehouse lavender? :-)
>
> Reg,
> Fred F.
>
>
>
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