harry.allerston - 30-12-2005 at 09:58 AM
Just alittle question ive wanted to know.... what is the difference in power and handling characteristics between high and low aspect kites? i need to
know as i'm planning on making my own kite with foilmaker templates.
does anyone have experience with building kites who can giv eme some top tips
coreykite - 30-12-2005 at 12:26 PM
Ahh Harry,
You've bitten into the big one with this question.
Without going into low-speed aerodynamics (too much) this is the nutshell:
(I assume you know most of this, but provacative questions sometime find a wider audience)
The wider aspect increases speed and maneuverability.
Lower-aspect enhances stability.
Note that single-line foils tend to have a narrower span (wingtip to wingtip) and a deeper chord (the distance from the leading edge to the trailing
edge) while steerable foils tend to have a wider span and narrower chord.
Foils generate power by increasing their speed through the air.
The faster the airflow over and under the foil, the more power it has.
Longer , narrower and even thinner foils have the potential to fly faster, particularly out near the edge, and thereby generate more power (be more
efficient - closer to theoretical limits) in the same relative wind.
Faster foils can also over-fly the edge and be prone to collapse.
They require constant awareness and a more subtle hand to realize their potential.
Most all the "power" foils are of wide-aspect.
Some more than others.
Newcomers to power kiting, without any memory of kites like these to draw upon, seem to inclined to want the kite to just hang there in the sky and
"be the boat".
Some designers (Peter Lynn and Ozone - in particular) have developed product well-suited to this.
Most of us fixed-bridle foils folks seem to like a balance between out-and-out performance and some degree of stability.
We like to fly the kite around to build power... It's fun!
Yet on some days it's just perfect to lock the kite into the sky and cruise.
Last year at NABX (or maybe it was the one before...) I watched Peter, leading the race, flying a big Phantom (that just hung there in the sky),
followed closely by a 3m Ozone Samurai, being flown very aggresively.
As the prize money at buggy races is non-existant,
I run for pleasure, not profit.
As with life, kite design is a matter of compromise.
Safen Up! Buggy On!
"Often wrong... Never in doubt"
the coreylama
Scoopy - 1-1-2006 at 10:07 AM
To sum it up in a nut shell-
High aspect-very aggressive, fast, harder to turn, more power per square meter, more unstable.
Lower aspect-slower, turns faster, more stable, not so much power per sq meter, not quite so aggressive, more smooth
Scoop
action jackson - 4-1-2006 at 04:29 PM
uhhh? unstable, i think not and the high ar won the race too!..........aj
Scoopy - 5-1-2006 at 02:24 PM
unstable compared to a lower ar. Generally speaking talking about aerodynamics. there have been some great improvements lately in the high aspect
kites, but they still dont hold a candle to the stability of the slower low ar kites.
Scoop