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Importance of wing AR?

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Peter_Frank
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Re: Importance of wing AR?

Postby Peter_Frank » Thu Sep 28, 2017 6:12 am

slowboat wrote:
Thu Sep 28, 2017 4:08 am
Peter_Frank wrote:
Wed Sep 27, 2017 9:19 pm
.... as soon as the wind starts to pick up, they becomes too slow really fast ......
Can you explain what you mean by this?
Aaah, yes, my mistake - the word fast in our language is used for a kite that flies fast, and we deliberately say "fast turning" if we mean that.

I sometimes forget that in English one says "fast" about a fast turning kite, and I actually dont know what to say about a fast flying kite (faster/flatter profile seeks to the edge better) :-?

Used the wrong term, I meant it will soon feel too draggy and slow (gliding), the big wings, when wind picks up :D

8) PF

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Re: Importance of wing AR?

Postby TomW » Thu Sep 28, 2017 7:01 am

My translation, being a native English speaker that speaks Swedish fluently ( can read but not understand spoken Danish!) .

" as soon as the wind picks up, big wings rapidly become slow and have a lot of drag. "

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Re: Importance of wing AR?

Postby BWD » Thu Sep 28, 2017 4:10 pm

faster/flatter profile seeks to the edge better
often in English a kite that goes to the edge is said to be "more forward-flying."
This way you don't confuse anyone by getting into airspeed, apparent wind, speed over ground, vmg, lift to drag ratio, or other qualities like turning etc.

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Re: Importance of wing AR?

Postby diogovilla » Thu Sep 28, 2017 6:09 pm

Peter_Frank wrote:
Wed Sep 27, 2017 9:39 pm
Kykeon wrote:
Wed Sep 27, 2017 9:33 pm
http://www.alpinefoil.com/pages-hydrofo ... ort-1.html

This one has an AR of 4.32 which is perfectly within the range you recommended and with 700cm2 it's bigger than average

Spot on, it would be my choice Diego, that very wing with your normal mast, awesome :thumb:

But can not tell whether you would prefer the short mast and Takuma wing style, or the Alpine Wave wing :wink:

8) PF
Thanks Peter and Kykeon,

I will give the Alpine wave wing a try.

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Re: Importance of wing AR?

Postby Regis-de-giens » Thu Sep 28, 2017 11:35 pm

From what I understand I again adhere to peter point of view.
When winds comes to low end I prefer my mid/high AR of the ketos Easy thanks to its better upwind ability. While the ketos wave (medium/low AR , which i love with enough wind) has more difficulty to stay upwind and generate apparent speed. It arrived that I could not stay upwind with the Wave wing , specially with low or medium AR kites in light winds, while it never happend with the Easy (on top of it higher area , it builds additionnal power when riding at a closer upwind angle instead of struggling).

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Re: Importance of wing AR?

Postby Kykeon » Fri Sep 29, 2017 8:14 am

How does the surface area of your easy compare to your wave?
Isn't it 50% larger?
I'm not sure if this has more effect in light winds than the aspect ratio. (from theory only)

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Re: Importance of wing AR?

Postby Peter_Frank » Fri Sep 29, 2017 8:56 am

Kykeon wrote:
Fri Sep 29, 2017 8:14 am
How does the surface area of your easy compare to your wave?
Isn't it 50% larger?
I'm not sure if this has more effect in light winds than the aspect ratio. (from theory only)

Definitely so, 50 % bigger, if it is the old Easy wing versus the Wavewing, and this has more impact than AR, your are right.
The WaveXL wing is about the same area as the Easy, but the AR is almost 25 % higher for the easy and not as swept, so this impacts the low end part of the low end in real life significantly :D

The wavewing is smaller and also low AR, but faster (in speed, eventhough also superfast turning, I have to learn to be specific) so in more wind it lifts like a tad bigger wing and definitely not like one 50 % smaller :lol:

We are maybe a bit off topic now as discussing our Ketos wings, but on the other hand spot on the very topic :rollgrin:

8) PF

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Re: Importance of wing AR?

Postby geron » Fri Sep 29, 2017 7:15 pm

Hello, good to learn a bit in this regard. The other thing that would be good to know is the effect the thickness of the wind compared to the width; it seems to me that 1 to 10 is the norm. But I wonder if this is because a thinner wing would be more efficient but they are not made thinner because of strength and construction restrictions?

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Re: Importance of wing AR?

Postby Peter_Frank » Fri Sep 29, 2017 9:37 pm

geron wrote:
Fri Sep 29, 2017 7:15 pm
Hello, good to learn a bit in this regard. The other thing that would be good to know is the effect the thickness of the wind compared to the width; it seems to me that 1 to 10 is the norm. But I wonder if this is because a thinner wing would be more efficient but they are not made thinner because of strength and construction restrictions?

Hi - thickness does not matter much, it is the curvature of the wing, also called camber, particularly the top side, that determines how much lift a wing can obtain.

The more lift though, the more drag at lower lift (higher speed), one can not get both.

Yes, many wings has a 10:1 ratio chord:thickness.

8) PF

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Re: Importance of wing AR?

Postby geron » Fri Sep 29, 2017 9:58 pm

Thank you Peter; I wonder what would be the characteristics of a very low aspect wing 1-2, with a very high surface area (1000 cm2) and a very low chord ratio (1-15)?
I want to think that it would be a wing that you could go very slow with a high angle of atack (more back foot pressure) but you could also go ver fast since it would not generate too much drag (because of the low chord ratio)


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