Re: Single-surface kite wing OZONE ?
--- In AirborneWindEnergy@yahoogroups.com, "Joe Faust" <joefaust333@...> wrote:
> > XXLite single surface kite for paraglider use:
> Ozone XXLite: Lightweight R&D <http://vimeo.com/29247558>
> > Will this kite play in systems that generate electricity or pump fluids?
I need to change my phrases a bit. My position is that the OZONE offer is not a true "single-surface" airfoiled wing. This should not lessen the newsworthiness of the offer; I just need to reserve "single-surface" for wings that fully earn such description.
The offer is probably not a true single-surface wing. Air flow aft of the stream stagnation point or separation point goes to top surface of an airfoil and to the bottom surface of the airfoil. In the video there is clear partial bottom surface material aft of the air flow separation point. This offer of OZONE is using an airfoil format that has a top surface and some bottom surface material. A true single-surface wing has not thickness except for one thickness of sheet used exactly for just one of the two, pick your choice top or bottom, but not both. The Rogallo Wing parawing is single-surface; the gliding PlaySail is single surface; the Allison kite-glider is a single surface; but the offer of subject and the Culp Wing OutLeader (though of a single fabric) are not airfoils of single surface, as they have a shaping that brings on material below the stagnation point forming airfoil surface, that is, the bottom surface of the airfoil, even if the % of full chord is small, but substantial. Differently, look to some true single-surface PGs when applying the term "single-surface" SSPG.
--- In AirborneWindEnergy@yahoogroups.com, Bob Stuart <bobstuart@...> wrote:
> I guess for a true single-surface kite, we'd need a Mobius Loop. :-)
Yes! Serious exploration of Bob's single surface Mobius Loop or Band: http://www.flair.monash.edu.au/publications/pdfs/lewthomhour2009jfs.pdf
However strong is the valid one-surface mathematical Mobius Loop or Band,
there has been a running culture in material airfoils that face a thin material that is not wrapped to form D-tubes or fat leading edge structures or wrap backs into a running second deck for "single-surface" crafted wings; else such wraps and forms form thick airfoils with "upper surface" and a far-away second surface that is farther away than just the thickness of the thin material. In that relaxed culture, I get, so far:
Wrap to get thick airfoil, even using a contiguous textile or sheet of aluminum, etc., and get double surface wing. The wing might be double-surface for say 15% of the chord. If a little bit pregnant, then pregnant, even if one's ear is not the pregnant site.