Spiroid winglets

[Ciwai]

Browsing through an aviation magazine, I chanced upon a term I hadn't heard of before, spiroid winglets. Typed in google and got this cool shiite:

http://www.aviationpartners.com/company/concepts.html#

Click on the pictures, the tips are actually looped surfaces.

Anyway, I was always curious why the intersection of endplates and wing is always consistently an abrupt perpendicular abutting of two surfaces, instead of something with smoother contours. I suppose it maximizes surface area of the wing, but it seems like it might be an area that teams could exploit for drag reduction.

[West]

BAR's winglet probably works along the same lines.

[Monstrobolaxa]

I've know for some time now about these wing tips (spiroid-winglets/wing tips) but according to the document it reduced drag more then 10%.

There is another kind of winglet called the "minex" don't know if it is correctly written but in wing tunnel testing it reached up to 25% reduction in drag! This "minex" winglet is more or less a toilet paper tube with cuts on the side so that the induced drag (wing tip drag) enters the tube and inside the tube the vortex is reduced.....if I find a link I'll post it

[Lightning McQueen]

Hi Monstro,

if you are interested there is a website about
"minix" winglet.

Here is the link : http://www.minix.fr/

Is both in English and French.
Hope that you find it interesting.