JS wrote:Birds are pretty good at grabbing any opportunity that they can get, but I don't think you could ever isolate miles of horizontal windshear without any vertical displacement or mixing.
And in real life, the windshear will never be a perfectly even gradient across great horizontal and vertical expanses, even in the middle of an ocean. If a bird flies headlong into increased headwind (or reduced tailwind - same thing, relatively) he can use the newfound kinetic energy to soar higher, and he'll probably be pretty intuitive about changing course to take advantage of the next horizontal gust or gradient.
In a gusty environment (usually near geographical obstructions), any windshear near the surface is better characterized as turbulence, and in wide open, steady surface winds, evenly distributed windshear isn't significant enough to turn a kiteboarder into a soarer.
I agree mostly, but 22 seconds of hangtime wasn't just caused by horizontal gusts.
And there is almost no such thing as a purely horizontal gust with no vertical displacement involved. You can't have a horizontal gust blasting along the surface without coming from somewhere, going somewhere, and displacing the slow moving air in its way.
Many sailors and kiters would do well to perceive wind and gusts as three-dimensional phenomenon, instead of the conventional two.
spork wrote:I believe you could dynamically soar indefinitely in a strong enough steady wind gradient with proper kite control.
Not when you are doing about 20 kts at a 6:1 glide ratio, sinking at 500 fpm.
spork wrote:I'm not sure I'm ready to buy your 500 fpm sink rate. In my 14.0 sq-meter glider I sink at about 185 fpm. I'm sure I sink faster on my kite but I would guess it's more in the 300 fpm range.
JS wrote: I do believe that 6:1 or maybe 7:1 is the best L/D we can expect from any current LEI kites, lines and/or bridles.
What is the L/D ratio of your 14.0 sq m glider at 185 fpm?
spork wrote:Interestingly enough I just this moment took a guess at the angle I think I see when I try and eye-ball it. I figured about 80 degrees - which comes out to a bit under 6:1 (of course 85 degrees comes out to over 11:1 and I'm sure I don't guess that well).
JS wrote:Don't forget to account for the weight of the kite....
stacey wrote:Here are my 17 seconds. Sorry I missed the beginning ... I'd been concentrating on the Ramp of Carnage, waiting to see who would hit it first ...
Users browsing this forum: Exabot [Bot], Google Feedfetcher, jannik and 23 guests