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lekaks
Since 02 Apr 2008
151 Posts
Hood River, OR
Stoked
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Fri Jun 21, 13 1:05 pm Vortex Generators on Kites? |
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Has anyone tried installing vortex generators on kites? In planes they have proven to decrease stall speeds and enhance low speed flight control all without degrading high speed performance. These results are all benefits to us, especially in light wind and wave riding where a low stall speed (kite drift) is desirable.
http://en.wikipedia.org/wiki/Vortex_generator |
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scottman
Since 08 Jun 2007
150 Posts
hillsboro
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Sun Jun 23, 13 11:29 am |
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I think ocean rodeo played around with a slotted flap concept. |
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sfbomber

Since 27 Jun 2012
114 Posts
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Sun Jun 23, 13 12:10 pm |
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As did Flysurfer in 2004, they called it jetflap technology. Bare in mind, the foils and speeds used by airplanes are much different than kites. |
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scottman
Since 08 Jun 2007
150 Posts
hillsboro
Stoked
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Sun Jun 23, 13 2:45 pm |
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Sheeting out must be good enough |
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lekaks
Since 02 Apr 2008
151 Posts
Hood River, OR
Stoked
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Mon Jun 24, 13 9:25 am |
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sfbomber wrote: | As did Flysurfer in 2004, they called it jetflap technology. Bare in mind, the foils and speeds used by airplanes are much different than kites. |
Many STOL aircraft stall at 30 MPH or less and make use of vortex generators to reduce that speed further. Anyway, I'm going to play around with the idea and take some notes. I'll let you know how it goes... |
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Nak

Since 19 May 2005
4304 Posts
Camas
Site Lackey
CGKA Member
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Mon Jun 24, 13 7:29 pm |
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This could be a very interesting experiment if nothing else. The first thing you need to do is get some data on the airfoil/kite. You need to know how to thick the boundry layer is first off. Since a wind tunnel is out of the question, you need an area with extremely steady winds. Use a smoke generator to observe the boundry layer and where the airflow seperates from the wing. You'll need a way to accurately measure both wind speed and angle of attack. Obviously, the kite will have to be tethered. 2 inch Long threads attached to the kite In a number of locations will also help you to monitor the air flow. Meticulously record data at various air speeds and angle of attack settings.
Once you have your "before" data, you can introduce the vortex generators. Make sure they are no more than 80 percent as tall as the boundary layer is thIck. If they stick up out of the boundary layer, You're going to lose any effectiveness they might have had.
My gut instinct is the vortex generators won't be worth having on the kite. I could easily be wrong though. Without the data gained hrough experimentation, there really is no knowing. |
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Weaz

Since 23 May 2012
360 Posts
Beaverton
Obsessed
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Mon Jun 24, 13 8:41 pm |
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One other thing to keep in mind is that force is also generated on kites by drag. It's not 100% lift as you would find on aircraft wings. _________________ Switch Nitro II (8m, 10m, 12m)
2011 Slingshot Key (10m, 13m) |
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stevo911_
Since 21 Aug 2011
9 Posts
Victoria
Kook
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Tue Jun 25, 13 8:40 am |
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scottman wrote: | I think ocean rodeo played around with a slotted flap concept. |
They call it Venturi Technology, it is in use on the Razor, Flite, and their newest offering The Storm (and it was on the Rises up until their retirement)
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scottman
Since 08 Jun 2007
150 Posts
hillsboro
Stoked
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Sat Jun 29, 13 10:33 am |
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Back in the day, for windsurfing sail development, guys horizontally mounted a sail on a 4x4 truck. They drove around on the salt flats? recording data. That way they could control the wind speed. They had a bunch of sensors and could accurately set angle of sail etc. You could probably do something similar with a kite.
But you got to ask yourself how often do you stall the kite and what is the benefit you will get? Real world would probably only be useful for 15M kite? |
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borntofli
Since 29 Apr 2010
90 Posts
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Sat Jun 29, 13 11:35 am |
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The ocean rodeo kites that had the vent were total crap..... I had a couple rises and renamed them fall......No drift......I think the vortex generators would have most of their effect at higher kite speeds. Standing on the beach I would doubt any positive effect.....
Very interesting..... |
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