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GK Sonic 11m- the one kite quiver

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ed257
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Postby ed257 » Fri Sep 30, 2005 11:36 pm

Here is some info from "The Bow Concept" in the news section.

The main innovation consisted in putting sweep, i.e. to move back the wing tips compared to its centre until the trailing edge is concave, which makes it possible to flatten and perfectly tighten this one. This is associated to an original and very simple bridle device, only fixed on the leading edge, conceived to allow almost full depower and a great turn speed.

Swept-back + simple bridling on the leading edge only, here is what differentiates the BOW concept from all other flat wings.
Many alternatives of planforms and bridles are possible inside this concept. Thus the Nova such as it is presented today was developed by the Takoon designer, Nicolas Caillou and has a different form from the Nova exposed to the Paris Boat Show in December 2004 and which was a Legaignoux design.

http://www.kiteforum.com/phpbb/news_show.php?m_id=140

and

http://www.grc.nasa.gov/WWW/K-12/airplane/kitefor.html

Ed

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windshreder
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Postby windshreder » Sat Oct 01, 2005 12:18 am

windshreder wrote:
ed257 wrote:
Part of the definition of a bow kite is the tow points are behind the center of pull.
Ed

Ed,
If the tow points are behind the center of pull, the kite would pitch up to full power all the time. Rear lines would be useless.

Can you explain your statement?


Ed,
I dont know your profession, but as a pilot with 12,000 hours in props to supersonic jets, I do not need an aerodynamics lesson to understand how a kite flies....

Anyway, you still didnt explain the tow point behind the center of effort?

Who is paying royalties for the bow patent?

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ed257
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Postby ed257 » Sat Oct 01, 2005 3:39 am

[/quote]
I dont know your profession, but as a pilot with 12,000 hours in props to supersonic jets, I do not need an aerodynamics lesson to understand how a kite flies....

Anyway, you still didnt explain the tow point behind the center of effort?

Who is paying royalties for the bow patent?[/quote]

Sorry, I don't have a Phd in aerodynamics. Just look at the bow kites (side view) vs C-kites. I think the difference in the shape and where the lines attach relative to the center of effort is pretty obvious and explains the ability of bow kites ability de-power so completely compared to C-kites depowering maybe 20% or so.

kjelleren
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Postby kjelleren » Mon Oct 03, 2005 1:18 am

I just received Kiteboading Magazaine and it had the MSRP for the Sonic listed at $1149. I have heard that it is going to go for $1380 in the US. What are others hearing about the price. I understand the whole supply and demand thing. Litewave Dave indicated that they have about 350 orders for the first shipment of 60 kites. Seems like lots of anticipation. I am riding Globeriders now and they are great kites. Can't wait to ride the Sonic.

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Postby GregW » Mon Oct 03, 2005 9:10 am

ed257 wrote:

I dont know your profession, but as a pilot with 12,000 hours in props to supersonic jets, I do not need an aerodynamics lesson to understand how a kite flies....

Anyway, you still didnt explain the tow point behind the center of effort?

Who is paying royalties for the bow patent?[/quote]

Sorry, I don't have a Phd in aerodynamics. Just look at the bow kites (side view) vs C-kites. I think the difference in the shape and where the lines attach relative to the center of effort is pretty obvious and explains the ability of bow kites ability de-power so completely compared to C-kites depowering maybe 20% or so.[/quote]

This is correct. The bows can depower because the tow point is well **forward** of the centre of effort, as can be seen in any side on photograph, not behind. Perhaps you guys are having a disagreement over a minor typo.

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Wawando
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Postby Wawando » Mon Oct 03, 2005 11:31 am

GregW wrote:...
This is correct. The bows can depower because the tow point is well **forward** of the centre of effort, as can be seen in any side on photograph, not behind. Perhaps you guys are having a disagreement over a minor typo.


Hi,

Greg, i think it is not like you say.
From what i have undestood, what alows bows to have so much depower as two things:
1) the centre of effort MOVES when you sheet in/out (that is one of the reasons why they have a moving wheel between front and back lines).
2) they turn in a different way, so you can always turn the kite (in traditional attachement point, if you depower too much you loose turning ability). If turning mechanism (or teh aerodinamics that make them turn) was like the traditional kites, they would not turn when fully depowered.

See you!

GK
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Postby GK » Tue Oct 04, 2005 3:47 am

kjelleren wrote:I just received Kiteboading Magazaine and it had the MSRP for the Sonic listed at $1149. I have heard that it is going to go for $1380 in the US. What are others hearing about the price. I understand the whole supply and demand thing. Litewave Dave indicated that they have about 350 orders for the first shipment of 60 kites. Seems like lots of anticipation. I am riding Globeriders now and they are great kites. Can't wait to ride the Sonic.


The magazine misprinted the msrp, the number they printed was Euros
instead of USD. As we all know, the dollar is falling faster than a
hindenburged kite.

As far as the issue of center of effort, it should always be behind the tow
point, or else the kite will fly backwards. True, the COE does move back
and forth on a 'bow' kite, just like with any kite which has variable angle
of attack. The difference with the Sonic is that the tow point moves with
the center of effort due to the mechanics of the KPO. That's why the bar
pressure is so light. When you sheet the kite in, the KPO moves back and
the load remains on the front lines, instead of transfering all the pressure
to the back lines. It's simple physics.
Due to the fact that the COE moves so much on a flat kite, its possible to
sheet too far and move the COE forward to the point that it passes the tow
point, making the kite fly backwards and loose all power. This happens
mostly in light wind when there is little pressure under the wing.

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ed257
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Postby ed257 » Wed Oct 05, 2005 3:23 am

GK wrote:Due to the fact that the COE moves so much on a flat kite, its possible to
sheet too far and move the COE forward to the point that it passes the tow
point, making the kite fly backwards and loose all power. This happens
mostly in light wind when there is little pressure under the wing.


If so, then the Sonic should be capable of "reverse launch" from a nose down position in the water. Is that true?

Ed

GK
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Postby GK » Thu Oct 06, 2005 12:57 am

ed257 wrote:
If so, then the Sonic should be capable of "reverse launch" from a nose down position in the water. Is that true?

Ed


Yes, for sure. Thats the best way to launch when you're under powered.
I think it would be easier with grab balls on the end of the leaders though.
When its windy, you just grab your own balls!

GK

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Postby macca » Sat Oct 08, 2005 10:47 am

GK wrote:
ed257 wrote:
If so, then the Sonic should be capable of "reverse launch" from a nose down position in the water. Is that true?

Ed



When its windy, you just grab your own balls!

GK


:lol: :lol: :lol: :lol: That goes for all kites.

Looking forward to seeing one in UK, sounds like they will be the answer to a one kite quiver.


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