What makes an elliptical canopy...well elliptical?

[Viking 0]

Is it the pure shape of the wing, the position of the pilot in relation to the center of the wing? I have no clue what makes elliptical canopy what they are so please explain. I swear you must have footprints on the back of your helmet

[lazerq3 0]

I would think that it has to do with the shape. you have round chutes that are well......round. Square chutes that are square shaped, semi elipticles that have an elipticle curve on the nose and tail but then straighten out on the sides , and then full elipticles that take on the shape of an elipticle circle! Some one want to confirm or clairify?
jason
A-38658 (the "A" stands for Aint quit to a "D" yet)

[SkydiveMonkey 0]

As far as I understand thats about right. The aspect ratio also has something to do with the performance ie. the ratio of the width to the length. The higher the aspect ratio the better the performance. I think the Sabre had about 2.5:1, whereas the extreme canopies have more like 3.5:1. (Is that about right?)
Live to pull and pull to live

[xAer0 0]

Correct me if I'm wrong , but...
The ellipticals are not curved at the sides forming an ellipse, they straighten out too, but the curvature at the tail and nose is heavier than a semi-elliptical.Aspect ratio on those is given by Span^2 / wing area , whereas the aspect ratio on squares is given by Span/Cord...and I would disagree on that 3.5 aspect ratio of the extremes...the only 3.5 aspect ratio canopy I'm aware if is the Onyx, and that because I've heard CobaltDan saying it...2.8 is as far as todays cross-braced ellipticals go, I think...the more the aspect ratio, the more efficient the wing.
Also being ellipticals reduces the wingtip vortices creating a more efficient and fast wing...and you probably know all the other stuff about faster turns, oversteering usually etc...
Dunno, am I correct?
Don't pull low, unless you are afraid of heights!
Tefkros

[cobaltdan 0]

basically, any canopy that does not use the same cross-section rib on every cell can be considered elliptical.
tapered, semi-tapered, ellipticall all mean the same thing: that the rib section is not constant.
i keep pointing out that performance of a canopy design is goverened by the sum of many design elements, not just if it is elliptical or not. all an elliptical plan form means is that it is potentially a more efficient wing. still many people do not believe this, all you have to do is look around at a dz. ie. there are heavilly ellliptical canopies that are docile student canopies and there are square canopies that are pocket rockets.
ie. the ultra high performance cross braced canopies on the market are very square compared to even many 'semi tapered' canopies
sincerely,
dan
atair

[Designer 0]

Laying all top & bottom skins next to each other paints the pic.A true Elliptical would be TOO FAST!Think about a new shape for END-CELLS and How could U fly it?

[Designer 0]

Laying all top & bottom skins next to each other paints the pic.A true Elliptical would be TOO FAST!Think about a new shape for END-CELLS and How could U fly it?Triangles Maybe?How many Line Attachments do u really need?

[RemiAndKaren 0]

Quote

A true Elliptical would be TOO FAST!Think about a new shape for END-CELLS and How could U fly it?

Man I hope this is a troll.... but I'll bite
Have you looked at Paragliders? I'm not sure if they are pure elipses, but they have to be damm close... and they do not fly fast... they are designed to fly for ever...
Remi
Muff 914

[billvon 3,090]

Any canopy whose sides have a narrower chord than its center is elliptical. Some are very elliptical (Stiletto) some are mildly elliptical (Spectre.)
-bill von

[Engovatov 0]

http://www.zvezda-npp.ru/ppd/prod/berkut_r.htm
It is more "elliptical" then anything out there, but accoriding to this URL is designed for accuracy jumping. It got like 3 open cells. You can order one from "Zvezda" - company that makes russian ejection seats and space suits among anything else.
This one also looks interesting - notice the end cells:
http://www.zvezda-npp.ru/ppd/prod/golf_r.htm
They are closed completely...

[freeflir29 0]

Dude! That has to be the craziest looking canopy I have ever seen.....Leave it to Russian engineers to build crazy stuff! They really tend to think outside the box.
"The cab driver said... he recognized my girly by the back of her head" -Beasty Boys
Clay

[Viking 0]

That first one must take forever and a damn day to open!!!!! only three open cells!!!!
I swear you must have footprints on the back of your helmet

[freeflir29 0]

"That first one must take forever and a damn day to open"
No shit! I can see the advertisement now. Patented "Slow as Fuck" opening! Watch the web video of a 700 Knt "just jumped out of an SU-27" opening...LMAO Look out Cobalt Dan. You may have some competition for the safety concious Free Fliers.
"The cab driver said... he recognized my girly by the back of her head" -Beasty Boys
Clay

[cobaltdan 0]

that russian canopy has 4 open cells and due to their size could probably be landed
with mid section only. inlets are not needed on the sloped cells due to the crossporting.
it probably opens quite fast actually, the center section is huge and cut like a reserve.
wierd looking... :)
btw. true ellipse planforms are possible (onyx) and many paragliders.
dan
atair

[Engovatov 0]

>due to their size could probably be landed with mid section only
I would doubt it - it is offered in 210 ft2. Stated purpose - jump into confined spaces and accuracy jumping. Claim a very high speed range and good stability in deep braked approach.
But - how do you pack one?? ;-)