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flipper
Since 17 Oct 2011
320 Posts
Obsessed
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 Tue Jul 24, 12 8:55 pm Max kite pull? |
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| What would the max pull be on a 12M kite, moving as fast as it can through the mosts powerful zone in the wind window? Have there been any studies on this? I figure if it can rag doll a 200 lb person, it's gotta be a lot of pull. |
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Slappysan
Since 13 Jun 2012
309 Posts
Obsessed
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| Tue Jul 24, 12 10:10 pm Re: Max kite pull? |
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| flipper wrote: | | What would the max pull be on a 12M kite, moving as fast as it can through the mosts powerful zone in the wind window? Have there been any studies on this? I figure if it can rag doll a 200 lb person, it's gotta be a lot of pull. |
The max will be based on the breaking strength of the kite, as it's purely a function of the speed (force) of the wind. Take a 12m kite out in 80 knot hurricane winds and it'll rip apart (while ragdolling the operator) |
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Youkai
Since 08 Feb 2010
553 Posts
Beaverton
Addicted
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| Wed Jul 25, 12 6:44 am Re: Max kite pull? |
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| Slappysan wrote: | | The max will be based on the breaking strength of the kite, as it's purely a function of the speed (force) of the wind. Take a 12m kite out in 80 knot hurricane winds and it'll rip apart (while ragdolling the operator) |
I think it's pretty safe to assume he means in normal kiting conditions for a 12m kite.
_________________
Captain kook; always wrong. |
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consumer
Since 28 Nov 2010
406 Posts
banned
Obsessed
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| Wed Jul 25, 12 6:57 am |
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| If you want to get really technical-I'd argue the limiting factor is not the ultimate strength of the kite but the maximum power generated is more a function of how much tension one can generate before being ripped downwind. I'd bet if you did the measurements you'd find that the peak force generated reaches a maximum value well before the peak theoretical drag force is reached. |
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EdG
Since 19 Dec 2005
425 Posts
Just a Kook that's
Obsessed
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| Wed Jul 25, 12 7:01 am |
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I'll wait for the official 'NAK' report with all the details  |
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OG
Since 07 Jun 2011
599 Posts
Addicted
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| Wed Jul 25, 12 7:19 am |
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| EdG wrote: | | I'll wait for the official 'NAK' report with all the details |
wise. though, i frequently still dont understand after NAK says it. |
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MarkWorth
Since 02 May 2011
149 Posts
Hood River
Stoked
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| Wed Jul 25, 12 8:01 am |
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I had a student who tied himself to a 1000 pound piece of concrete to teach himself to kite. After the concrete chased him across the parking lot he decided lessons would be safer way to learn.
The other way to max out the kite is to get deep in the water, the classic tea bag approach works great for getting about 12 feet underwater. When the kite powers up with the rider deep they can get really serious pull.
When the 600 lb test lines start popping you know the kite’s pulling hard.
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Have More Fun!
Mark
Gorge Kiteboard School
http://gorgekiteboardschool.com |
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FlyDunes
Since 09 Oct 2007
1034 Posts
Aloha
XTreme Poster
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| Wed Jul 25, 12 11:52 am |
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I've done the math. The max pull is "4".
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Lets FLY |
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Youkai
Since 08 Feb 2010
553 Posts
Beaverton
Addicted
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| Wed Jul 25, 12 12:05 pm |
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| FlyDunes wrote: | | I've done the math. The max pull is "4". |
Awesome. Thanks Steve. I knew if you answered it would be quality.
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Captain kook; always wrong. |
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Jonpnw
Since 22 Jul 2010
1327 Posts
Pacific Northwest
XTreme Poster
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| Wed Jul 25, 12 12:12 pm |
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| EdG wrote: | | I'll wait for the official 'NAK' report with all the details |
Nak Rules !
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Slingshot | Ride Engine |Try before you buy | PM me
Join the Columbia Gorge Water Sports Association. http://gorgewindsurfing.org/ |
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chrissmack
Since 08 Jun 2005
526 Posts
portland
Addicted
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| Wed Jul 25, 12 12:43 pm |
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| wasn't this already covered? strain gauges and all.... |
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Weaz
Since 23 May 2012
360 Posts
Beaverton
Obsessed
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flipper
Since 17 Oct 2011
320 Posts
Obsessed
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| Wed Jul 25, 12 9:51 pm |
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| Haha thanks for everyones replies. I'm thinking of getting a scale like the one at the old grocery store where you measure your bananas. I'm going to attach one end of the scale to a school bus and then the kite to the other end. Then I'm going to fly the 12m in figure 8s as fast as I can in 25mph wind. i bet it would be pulling 2000+ pounds. |
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Slappysan
Since 13 Jun 2012
309 Posts
Obsessed
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| Thu Jul 26, 12 8:48 am |
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| flipper wrote: | | Then I'm going to fly the 12m in figure 8s as fast as I can in 25mph wind. i bet it would be pulling 2000+ pounds. |
Your lines are only rated to 600 lbs. |
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BigR
Since 05 Jul 2005
372 Posts
White Salmon
Obsessed
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| Thu Jul 26, 12 9:01 am |
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| Quote: | | What would the max pull be on a 12M kite, moving as fast as it can through the mosts powerful zone in the wind window? |
The max pull could be very close to 2400 pounds of force, (assuming you are using
600 pound test lines on all 4 lines). That is assuming all the lines are tensioned
equally, which they will not. So if we assume only 2 of the lines are doing the pulling
your max pull becomes 1200 pounds.
More than this and one of your lines will break..... |
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cosmodog
Since 06 Oct 2005
204 Posts
Stoked
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| Thu Jul 26, 12 10:31 am |
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Here's my guess: ~1000 lbf
Assumptions:
12 m2 kite
50 mph kite speed (25 mph wind + kite motion)
1.2 lift coef (high)
Lift - 1/2*air density*velocity*velocity*area*lift_coef = ~1000 lbf |
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consumer
Since 28 Nov 2010
406 Posts
banned
Obsessed
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| Thu Jul 26, 12 10:47 am |
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| Don't forget that maximum pull just means maximum acceleration, you can theoretically pull a 30,000 lb object with a kite therefore, assuming its static/kinetic friction do not exceed maximum tension |
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