From: "Dwight K. Elvey" 
To: atm{at}shore.net
Reply-To: "Dwight K. Elvey" 


Hi
 For low heat differential, convection plays the largest
part. Air doesn't conduct heat very well. Radiation plays a part because
the sky is quite cold compared to the air and surfaces of your telescope.
Dwight

>From: "Emery Greg" 
>
>Hi All:
>
>What is the preliminary mode of heat transfer in telescopes?  Is there a
dominant mode or does it change from design to design?.  Tom Krajci
mentioned radiation in the wire spider thread.  Tube currents suggest
convection. Blowing
air with a fan through the cell onto the back of the primary is convection
and conduction.
>
>I am probably naive, I just don't see radiation being large in a spider or
secondary setup, I would ( and have ) assumed that for spiders all three
modes are operating with convection/conduction being dominant.  As
optimizing heat transfer requires identification of the modes, I am
interested in this before I start constructing my bino scope ( actually I
have started building already :)
).
>
>ttfn
>greg
>
>
>

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