Byron Brandon Ward wrote:

RULE NO. 1 for our cooling system is, exhaust the heated air at the same
level,
           or preferably higher, than the intake area.

Rule no 1. does not make sense to me. If this is from the website article
(sounds like it) this always caused some confusion to me. The guy says to
exhaust the heated air higher because hot air rises....but hot air only
rises if it is surrounded by cooler/more dense air. In the case of a
cooling system it is confined in a duct and therefore I can't see how it
would somehow want to rise. Am I missing something here?

Byron

Yes that would seem like a subtle factor. My guess is the *hotter*
lower density air in the duct would tend to be at the top of the 
duct somewhat impeding the overall mass flow. My guess it is not 
a strong effect but I could be wrong. Would be great for heat soak 
after you land however.

BTW if you can arrange the duct in such a way so that the controls
go through a tunnel close to the rad the air velocity will be lower
and hence so too will be the adverse effect of the control tunnel
on drag. I guess we need a sketch on that

Paul Lamar
 
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