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Aerodynamically better leading edge

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grigorib
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Aerodynamically better leading edge

Postby grigorib » Sat Jan 14, 2017 11:00 pm

Did anyone ever built a two-chamber, two-bladder, oval-shaped leading edge so it has less drag and is more aerodynamic?
I meant an internal rib in the middle throughout the LE and bladder in each chamber. It will be thin but will weigh a lot and probably won't deliver rigidity of a fat LE.

What if we go for cuben fiber and have a high pressure LE bladder?? That way all current kites will become obsolete already!! Won't it be the best solution??!!

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lovethepirk
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Re: Aerodynamically better leading edge

Postby lovethepirk » Sat Jan 14, 2017 11:17 pm

Can't comment on your ideas...but I've always wondered about a swimming noodle stuffed inside the leading edge with tapered ends :o :o :o

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Re: Aerodynamically better leading edge

Postby PullStrings » Sat Jan 14, 2017 11:28 pm

Image

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lovethepirk
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Re: Aerodynamically better leading edge

Postby lovethepirk » Sat Jan 14, 2017 11:49 pm

Come on PullStrings why you gotta cut my legs off like that? :) Imagine a curved, hollow, formed noodle :o easily slipped into the LE. It would work, but I haven't worked the math on the weight :)

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Re: Aerodynamically better leading edge

Postby Peter_Frank » Sun Jan 15, 2017 12:06 am

Yes, North did in in 2002 or 3 as far as I I remember, an oval two chambered front tube :D
But left it again.

I can not see many advantages, as if you decrease the diameter ever so slight, the double tube added stiffness with two tubes will quickly be "lost".

Meaning, stiffness is proportional to diameter cubed, so if you have the double stifness from two tubes, you can only decrease the diameter about 20% instead of 50%, so the gain is small compared to all the other disadvantages :roll:
But hats off that they tried it :hut:

8) Peter

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Re: Aerodynamically better leading edge

Postby iriejohn » Sun Jan 15, 2017 12:20 am

The LE diameter could be left the same to maintain rigidity but the LE front and trailing edges could be profiled into more aerodynamic shapes to reduce drag. Don't know how though, maybe internal ribs in the LE bladders?

grigorib
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Re: Aerodynamically better leading edge

Postby grigorib » Sun Jan 15, 2017 12:25 am

iriejohn wrote:The LE diameter could be left the same to maintain rigidity but the LE front and trailing edges could be profiled into more aerodynamic shapes to reduce drag. Don't know how though, maybe internal ribs in the LE bladders?
Let's say the front remains as is but if there's a second layer of ripstop from LE to main sail making it a drop-shape?

Doesn't need to be too wide, let's say 1.5x diameter of LE wide

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Re: Aerodynamically better leading edge

Postby iriejohn » Sun Jan 15, 2017 1:00 am

grigorib wrote:
iriejohn wrote:The LE diameter could be left the same to maintain rigidity but the LE front and trailing edges could be profiled into more aerodynamic shapes to reduce drag. Don't know how though, maybe internal ribs in the LE bladders?
Let's say the front remains as is but if there's a second layer of ripstop from LE to main sail making it a drop-shape?

Doesn't need to be too wide, let's say 1.5x diameter of LE wide
As long as it doesn't fill up with water when you crash.

grigorib
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For sale: Slingshot SST 6m 2018 $480, Slingshot Turbine 5m 2017 like new $450, BROkite carbon board 140x44cm like new complete $650, Slingshot Rally 6m 2017 like new $530

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Re: Aerodynamically better leading edge

Postby grigorib » Sun Jan 15, 2017 1:09 am

iriejohn wrote:
grigorib wrote:
iriejohn wrote:The LE diameter could be left the same to maintain rigidity but the LE front and trailing edges could be profiled into more aerodynamic shapes to reduce drag. Don't know how though, maybe internal ribs in the LE bladders?
Let's say the front remains as is but if there's a second layer of ripstop from LE to main sail making it a drop-shape?

Doesn't need to be too wide, let's say 1.5x diameter of LE wide
As long as it doesn't fill up with water when you crash.
It doesn't have to cover all length of the LE. It might be enough to have it span (and it can be stretchy material, not necessarily ripstop) between struts leaving couple of inches of gap on each side. Or maybe only have it on the eartips which don't produce less pull but plenty drag.

Did anyone tried this?

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Re: Aerodynamically better leading edge

Postby Puetz » Sun Jan 15, 2017 1:15 am

Peter_Frank wrote:Yes, North did in in 2002 or 3 as far as I I remember, an oval two chambered front tube :D
But left it again.

I can not see many advantages, as if you decrease the diameter ever so slight, the double tube added stiffness with two tubes will quickly be "lost".

Meaning, stiffness is proportional to diameter cubed, so if you have the double stifness from two tubes, you can only decrease the diameter about 20% instead of 50%, so the gain is small compared to all the other disadvantages :roll:
But hats off that they tried it :hut:

8) Peter
... nah it was Gaastra that made the double chamber LE, not North,,,, Gaastra Phoenix.


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