I suppose this has to do with the ratio between maximum pull and minimum (edge of window) pull, correct?BeamerBob - 4-10-2012 at 11:58 AM
I've wondered the same thing. The 2 really are the same thing, its just a difference of angle in the sky IMHO. From a buggy perspective, neither is
really a good thing. Grunty power means the kite is hanging back in the window a bit and catching lots of wind. Design the kite to run a little
further forward in the window and speed goes up while side pull goes down. None of this would apply to "pull" generated by turning the kite.awindofchange - 4-10-2012 at 12:04 PM
This can be quite confusing and hard to explain....but I will try to give a basic of what I feel. These are only my personal opinions, I am not an
aeronautical engineer.
Kites with very high amounts of lift are designed that way. These kites require very little movement to generate excessive amounts of "pull" to get
the rider airborne. I would assume they are designed more like a paraglider. Glide to lift ratios are very high, meaning that once you get airborne,
they tend to stay in the air longer / glide back down slower than normal kites. Kites that have high lift capabilities can get you airborne very
easily without as much need to really get the kite cranking and sending it hard. Depowerable kites can do this with just powering up the kite, when
nicely "lit up", you can get 2-5 ft floaters just standing flat on the ground and pulling in the bar.
Buggy kites (generalized term) tend to have more pull than lift. The difference here is that the kite has less tendency to get you airborne but does
require to be moving to generate the power. These kites are designed to create power when flown through the window at speed. They normally require
someone to be working the kite more to generate maximum power output. You can get airborne with any kite, but these types of kites will require much
more technique and high rates of speed and sending the kite back harder and faster to generate the lift. Once you get airborne with these kites, they
will descend back down at a much faster rate without giving you the ability to keep them airborne. Basically, once they stop moving at higher speeds,
they lose their power. The beauty with these types of kites is that the faster/harder you fly them the more power they will produce, unlike the kites
above where they tend to reach maximum velocity much quicker. These work especially well with a buggy because the harder you fly, the faster you will
go, the more power they produce. Once you bear off-wind and/or stall the kite or take the kite out of the power window, the power dies off fairly
quickly.
This is what I would classify the difference between lift vs. pull.
Hope that helps. I would love to hear other peoples ideas on this subject as well.Flyfish - 4-10-2012 at 01:08 PM
I may be off, but I think that "pull" relates to the airfoil and the amount of "lift" that it produces at a specific air speed. (the term lift here
being used in regards to the airfoil).
And "lift" (in kiter's language) as the speed that the airfoil generates "lift" (aeronautic lift) in response to an increase in angle of attack (which
comes either from a redirect or pulling the bar in). So a kite that develops lift quickly will rapidly overcome the weight of the rider and "lift"
them with more of a yank than a kite that develops lift in a linear development.
But a kite that has good "pull" already is flying at a high angle of attack and doesn't have much more ability to increase the angle.
Best two kites that I can think of would be a NASA kite that flys at a super high AOA, develops a HUGE pull, but won't jump at all.
The other side would be a high aspect ratio kite like the flysurfer speed that flys at a low AOA and needs alot of airspeed to generate lift, but when
redirected has tons of reserve AOA to generate lift.
My two cents...DemBones - 4-10-2012 at 07:32 PM
Kent described it well. A low lift kite can still generate a lot of pull if you can fly it fast enough. Hence a kite with a low AOA (low lift), and
high AR (fast), can provide a lot of power by moving it fast through the power zone.DemBones - 4-10-2012 at 07:40 PM
Quote:
Originally posted by geokite
How can a kite have large lift and small pull?
Not sure if this is possible (in a fixed bridle kite at least).Bladerunner - 5-10-2012 at 05:13 PM
I like Flyfishes explanation and it matches my thinking. Using the Nasa wing and speed as examples really drives it home.
A good example of a fixed bridle that shows the middle ground is the original Blade. It was a competetive race kite in it's day with it's high AOA yet
it is best known as a jumping kite. Adding brake down low gave a boost in speed. Adding brake when overhead boosted you !
I can picture pull without lift but can't picture lift without pull ?
Speed equals power !apextech - 5-10-2012 at 08:08 PM
I may be not be able to explain this the way it makes sense, and I may be just reiterating what others have already said, but it seems that low aspect
ratio kites be it foil or inflatable equates to a better traction type of kite, flys a bit slower and deeper in the window holding the winds power for
more of a tractor type pull, where as a higher aspect ratio kite flys faster and more forward in the window requiring more apparent wind to achieve
the lower end, but when that apparent wind is achieved it has the speed to radically provide more lift in short order, commonly referred to as "pop".
Being the cruiser buggy /mowing the lawn / park and ride kind of guy that I am I prefer the lower aspect "tractor" type of kite with no surprise
liftiness punishment for mishandling that can sometimes be delivered with higher aspect kites. BTW I refer only to depower kites as that is what I've
been used to flying.flyjump - 5-10-2012 at 08:44 PM
This is all really interesting. One of the things that I have noticed switching from arcs to the matrixx is the technique for jumping and it has
everything to do with how the kite flys. It seems like the kites that tend to jump easier always accelerate forward very quickly. Sometimes when you
are flying in strong winds with bigger jumping kites, when you originally dip the kite down into the window you are sometimes pulled backwards/upwind
aggessively because that kite likes to move to the edge of the window as quickly as possible.
Flying with large arcs in heavy wind all you have to do is send the kite hard and it lifts but you need to keep the kite moving and keep it high in
the window so you don't get dropped on the redirect. It seems like large foils like flysurfer/ HQ style you can kiteloop and when the kite is nose
diving in the center of the window you aren't getting pulled into ground you still have loads of float. I think the arcs pull you more into the
ground on loops because of the C-shape and not neccessarily the aspect ratio which is what I originally believed.
I guess the main thing that I have noticed is that kites that seem to be really lifty like to accelerate forward quicker than kites that dont jump as
well.Snake - 5-10-2012 at 10:39 PM
To me, lift vs. pull is the same as lift vs drag. The drag a kite creates is highest in the power zone. Lift occurs by the movement of the kite. The
faster the kite moves, the more lift it creates. Moving the kite through the power zone results in the kite having pull from drag and lift. Moveing
the kite around above you results is mostly lift and very little drag. Stalling the kite in the power zone results in mostly drag and very little
lift.John Holgate - 6-10-2012 at 04:47 AM
I think moving a wing through the air creates lift. That's what wings do. There is no 'pull'. It's all lift. But that has nothing to do with being
'lifted' So when people call a kite 'lifty' - I think it means that it creates plenty of lift high in the window - so it can physically 'lift' you.
A nasa wing creates plenty of lift - but it does it low down in the window and I think that's what people call 'pull'. But it's still 'lift'. ! As
far as I know, when inflated, a foil takes on an aerofoil shape and behaves like a wing - wings create lift, not pull. Anywho, that's my
understanding of it!!
