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Forum Index : Solar : solar cooking?

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MacGyver

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Joined: 12/05/2009
Location: United States
Posts: 1329

Posted: 04:05am 09 May 2011

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Here's An Idea

Does anyone know what the curve would be of a piece of aluminum-coated mylar plastic that is secured around the edge of a cylinder, then sucked into it by means of a partial vacuum?

My guess is it's a circle, but it'd be pretty cool if it were "troposkein". A troposkein is the curve a rope makes when hanging betwen posts with gravity pulling equally on everything. A partial vacuum would also pull equally (I think) on the mylar.

To the best of my knowledge (??) a troposkein curve is parabaloid. If this is true, it'd make a dandy way to fabricate a solar mirror, eh? The curve could be pulled using mylar-coated "n-preg" material which sets off an epoxy mix when stretched or heated.

Just an idea.

. . . . . macEdited by MacGyver 2011-05-10

Nothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas

petanque don
Senior Member

Joined: 02/08/2006
Location: Australia
Posts: 212

Posted: 02:14pm 09 May 2011

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I don�t have a PHD in maths I will suggest for cooking only a loose focus is needed

If the energy is focused onto an area 100 mm across there will be the same energy as if it is focused on an area only 10 mm across but the 10mm spot is a lot more likely to burn things.

As I understand satellite dishes have quite a tight focus the focal point is also a further away from the dish meaning that they need to be aimed more often and more carefully.

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