>Someone mentioned high-aspect-ratio sails - these do not, as I recall, gain
>their power because so much because they reach into higher wind, but because
>they have a relatively shorter foot and therefore lots less induced drag.
>Tom Whidden (president of North Sails) goes on and on and on about induced
>drag and sail shape in "The Art and Science of Sails" and since North is
>arguably the most technically advanced loft with extensive computer analysis
>and wind tunnel testing, I'm inclined to believe him.
I'm sure you're right. Sailplanes are designed for maximum lift-to-drag
ratio and have high-aspect-ratio wings. Aircraft designed for long range
also usually have long narrow wings for the same reason.
On sailboats, I've read that high-aspect-ratio rigs are faster upwind, and
low-aspect rigs are faster off the wind, all other things being equal. My
very-low-aspect-ratio lateen rig seems to demonstrate that. There is also a
greater heeling moment with a high-aspect-ratio sail. My lateen rig can
tolerate higher winds than my sloop rig even though the lateen has a little
more sail area than the original small main plus jib on my sloop rig.
Harry Gordon
P14 #234, Manatee
Mountain View, CA