Viper winglets?

[Kirils 1]

Anti-vortrex winglets is what I believe he called them. I recently saw a guy jumping one of these Geman Vipers and there was a rigid triangle on the edge of the top side.
They look pretty cheesy. Is it a gimmic or do they offer a performance advantage? Thanks!

"Slow down! You are too young
to be moving that fast!"

Old Man Crawfish

[Sonic 0]

Have a look on the Precision website - they offer something similar on one of their canopies.

-----------------------------------
It's like something out of that twilighty show about that zone

[skygod7777 0]

no performance advantage, just if you cut someone off, they won't feel you wing voticees as much. that's it, from what i understand, i'm not a canopy designer, i have just heard this, if someone else doesn't answere soon, i'll be back with an answer from my buddy at PISA (he's the engineer, designed all the PISA canopies)

later

[AndyMan 7]

In the attached images you can see winglets on both a Precision Nitron Canopy, and a Bombardier CRJ-700 regional jet.

In both cases, the winglets reduce air spilling off the end of the wing, resulting in greater lift at slower airspeeds.

_Am

__

You put the fun in "funnel" - craichead.

[roq 0]

I think the canopy is Nitro, no Viper, from Germany High Performance Research http://www.hipercanopies.de/

Roq

[darkwing 5]

This is not necessarily a comment specifically at the winglets you mention, but in general it is important to remember that just because something is sold, doesn't mean it actually works. Just because someone claims it works, doesn't mean it does. Just because they have data doesn't mean they interpreted it correctly.

-- Jeff
My Skydiving History

[markbaur 0]

Quote

the winglets reduce air spilling off the end of the wing

Looking at the Nitron photo, I see the stabilizer bowed out. That makes sense: higher pressure below the wing, lower pressure above, the air tries to sneak around the end of the wing (making vortexes) instead of flowing straight back (making lift).

So given that the stabilizer and the winglet-thingee do the same thing, why not just make the stabilizer bigger?

Mark

[skygod7777 0]

Quote

Looking at the Nitron photo, I see the stabilizer bowed out. That makes sense: higher pressure below the wing, lower pressure above, the air tries to sneak around the end of the wing (making vortexes) instead of flowing straight back (making lift).

So given that the stabilizer and the winglet-thingee do the same thing, why not just make the stabilizer bigger?

Mark

well, i don't think you want to make it bigger because of drag, at least that makes sense to me.

and i don't really understand why they are there. i mean you don't need them, or can't give that much more lift, other wise every canopy on the market would have them

just my opinion, and
opinions are like assholes.................everyone has em.............and they all stink

later

[pilotdave 0]

I have no clue what they ACTUALLY do, but I seriously doubt they reduce vortices at all. They more likely create vortices (which can be beneficial for certain cases). Winglet design on airplanes is extremely complex. They don't simply reduce vortices. They are designed such that they produce a little bit of lift in the forward direction (ie thrust). This counteracts some of the drag caused by the vortices, yada yada. "Real" winglets are not simply flat pieces that stick up off wingtips. They must be curved at just the right angle to produce the desired effect. They were originally invented by Whitcomb and shaped by trial and error till he got the desired results.

There may be a very good reason to put those things on a canopy, but they sure as hell arent winglets.

Dave

[Austin 0]

Those are not winglets...they are vortex generators. Vortex generators are used on some airplane wings, but I'd have to look it up in one of my textbooks to tell you why. But my guess here is that they create vortices that have countering rotation to the wing tip vortices created by the flight of the canopy.

Just a guess though.
Austin

[pilotdave 0]

Vortex generators have nothing to do with wingtip vortices. They are little pieces of metal that are placed in strategic locations just upstream from where flow is likely to separate (or stall, if you're talking about wings). They basically disrupt the flow causing tiny vortices to form along the surface. These bring high energy (fast moving) air from above down to the surface to prevent separation from occuring. Planes are never designed with them, they are added on when deficiencies are found after the plane is built.

Big strong vortices can be a good thing in cases like the back ends of tailgate aircraft. Because the fuselage has such a high upsweep on a plane like a skyvan, the flow will separate behind the plane, causing all kinds of drag. So, the designers do something sorta counter intuitive. Instead of rounding off the ass end to make it more aerodynamic, they keep all the corners really sharp. This causes distinct vortices to form, instead of just random flow separation like you'd get behind something like a ball or cylinder. These vortices carry high energy air from next to the plane into the area behind the plane. The flow around the vortices kinda gets sucked in a little behind the plane. So, instead of trailing a big chunk of low energy air behind the plane, the air flows smoothly around the plane. It's just as if the plane was much longer and tapered in toward the back.

Various vortex generating devices can be found all over most modern planes. Jet fighters have em everywhere. They can be used to control the flow all over the plane.

It's possible those things on that canopy do something, but I seriously down they have any effect on reducing vortices. Then again, they've done the research, not me.

Dave