Camber induced kites?

[dragnfly]

This has probably been covered before - and camber induced probably isnt quite the right term. Windsurfers will know what I am on about.
Have any kite manufacturers ever tried more profiled leading edges, making them the same shape as a camber induced windsurf sail? Surely it would make a kite far more efficient? Windsurf sails weren't ideal as the big gap would fill with water, but a kite would have the bladder filling the whole area, so wouldn't be an issue - but it might take a lot more pumping.
Like in the pic?
Just wondered. It may well have been tried before.

[tmcfarla]

I think you mean additional fabric behind the leading edge to clean up the profile? I think it has been tried. BRM did an April fools video about it a couple years ago, but if I recall, he actually made one and found that it had no affect on performance.

[zerogee_ca]

Faction kites back in 2003ish tried it. But they ever took off. Perhaps, it added complexity to manufacturing and cost?? Added weight?? Water capture and drainage issues?? For too small a gains??

https://goo.gl/images/XfEjrt

[cor]

[Mossy 757]

It's possible to create a high performance wing that doesn't come with all the compromises of a rigid wing using a double-skinned sail: https://www.sail-world.com/news/209295/ ... f-Mainsail

That said, kite design is very different than sail design. The double-sail America's Cup boats will be lighter than the rigid wing boats of last time, at a slight performance degradation. Kites are already at the very light end of the 'compromises' spectrum, so any time you suggest adding more material it needs to be unmistakable that there is a reason to do so.

I think foil kites do what you're describing very well, especially when they have a thick profile design and a long bar throw so you can really traverse a variety of 'shapes' within the sheeting range. I think a lot of inflatables change camber in a meaningful way across the sheeting range, but nowhere near as much as foils and with more turbulence on the underside due to not having a smooth bottom skin.

[Cab Driver]

This has probably been covered before - and camber induced probably isnt quite the right term. Windsurfers will know what I am on about.
Have any kite manufacturers ever tried more profiled leading edges, making them the same shape as a camber induced windsurf sail? Surely it would make a kite far more efficient? Windsurf sails weren't ideal as the big gap would fill with water, but a kite would have the bladder filling the whole area, so wouldn't be an issue - but it might take a lot more pumping.
Like in the pic?
Just wondered. It may well have been tried before.

There's a lot of torsion in a kite when it turns. That's how it turns - different angles of attack on the wingtips. Wide sleeve or double surface LE is direct resistance against torsion, or turning. This will likely be slow turning.

[mikelet]

Back in the day , Gaastra Phoenix has a more air-foiled LE with 2 cambers/2 bladders inside ....2003 or 2004 if i remember right ..
Never tried it , seems it doesn't have any success , a matter of weight/complicated construction vs performance i supose...

[Peter_Frank]

Back in the day , Gaastra Phoenix has a more air-foiled LE with 2 cambers/2 bladders inside ....2003 or 2004 if i remember right ..
Never tried it , seems it doesn't have any success , a matter of weight/complicated construction vs performance i supose...

Very true.

Also, the area behind the LE is not nearly as draggy and damaging as one would think, as stagnant air behind the LE, gives a virtual "second bottom skin" almost, which gives a lot more performance as one would think.

This is the very reason why windsurf sails have dropped cambers again, and going with a simpler design, as the gain is minimal compared to the disadvantages (weight, shifting side, cost etc, besides water inside)

The same goes in an even bigger respect for kites IMO, as here you will also lose turnability because the double skin would stiffen the LE.

Having a flexible leading edge that can twist (but hold its shape of course), not too stiff, enhances turning hugely.

Peter

[bragnouff]

Also because performance in kiteboarding is not about an optimized Lift/Drag ratio.
Stability, turning ability, instant depower, are typically much more valuable characteristics than just speed of the kite through the air.

For the few use cases where L/D matters, foils seem to cover that pretty well.

[tmcfarla]

Also because performance in kiteboarding is not about an optimized Lift/Drag ratio.
Stability, turning ability, instant depower, are typically much more valuable characteristics than just speed of the kite through the air.

For the few use cases where L/D matters, foils seem to cover that pretty well.

^ this.

This more or less explains 95% of the “wouldn’t it be better if kites were like...” that appear on this forum.