Power Kite Forum

new wind-powered speed record -- nearly 400 mph!

furbowski - 23-8-2009 at 04:30 PM

apparently folks flying really high-tech gliders have discovered something called dynamic soaring, need to see the video.

this is r/c stuff, these gliders pull 60 gs.

http://www.youtube.com/watch?v=WaQB16ZaNI4&feature=relat...

and yes 400 mph + is happening with these things....

never done anything like this myself, just stumbled across it.

don't worry if you don't see the glider at first, it's moving in a very tight and fast loop.

Kamikuza - 23-8-2009 at 05:19 PM

I would like to point out that it's not wind powered and it's not looping :D The idea is interesting but after a while, it looks kinda like NASCAR, with models ... in the air ... ie. dull :(

furbowski - 23-8-2009 at 05:24 PM

yeah, i wouldn't want to do it...

but it is wind-powered!

and the speeds are incredible...

Kamikuza - 23-8-2009 at 05:32 PM

Gravity powered, yes. Wind, no. All he's doing is trading altitude for airspeed and relying on a bit of ground effect (or ridge soaring, whatever that's called) to keep the thing moving beyond it's aerodynamic inefficiencies, which are probably very low on something that small and light.

Actually looks like fun but if there's that much wind out, I'd rather be kiting :D

furbowski - 23-8-2009 at 06:10 PM

granted, it's a trick of physics, they get soaring fast across the bottom then use that speed to loop up over and back down, and then just keep pushing it.

but without the wind drafting up the ridge, it ain't happening.... 45 mph gusts powered that.

agree to split the diff? "perverse application of gravity to good ole wind power?"

Houston AirHead - 24-8-2009 at 01:54 PM

you know they got money to burn.

Kamikuza - 24-8-2009 at 04:25 PM

I prefer the term 'exploit' :lol: but I'll agree with you on the split ;)
Actually, the more I think about it, the more kick-ass it is :ticking:

furbowski - 24-8-2009 at 04:34 PM

Quote:
Originally posted by Houston AirHead
you know they got money to burn.


ain't that right!!!

"exploit" is a very good word for what those boys are doing!!!

WELDNGOD - 24-8-2009 at 04:44 PM

check wiki. We learned it from Albatrosses . And it is wind related.

acampbell - 24-8-2009 at 04:55 PM

Quote:
Originally posted by Kamikuza
Gravity powered, yes. Wind, no. All he's doing is trading altitude for airspeed and relying on a bit of ground effect (or ridge soaring, whatever that's called) to keep the thing moving beyond it's aerodynamic inefficiencies, which are probably very low on something that small and light.

Actually looks like fun but if there's that much wind out, I'd rather be kiting :D


Wind yes, Gravity only for a moment. Ridge soaring is in fact soaring and is not ground effect (well maybe in a macro scale), and gravity is defied in the name of aerodynamics.

I'm a licensed glider pilot and it's been 25 years, but the physics have not changed, but the RC models sure have (and hand-held electronics). Pretty cool.

Kamikuza - 24-8-2009 at 04:58 PM

They aren't really ridge soaring though are they?

USA_Eli_A - 24-8-2009 at 05:03 PM

it's actually no wind speed record, ACTUALLY NOT AT ALL EVEN CLOSE THE SAME CONCEPT!

the record you are speaking of, is an Airspeed record, or a ground speed record for a glider. The glider isn't tethered, and isn't a kite, it flies off some crazy physical properties and just isn't any old glider, at 400mph it's substantially significant in it's own design.

as Wind Speed is always constant unless gusty, airspeed = how fast the wing moves in air, so air speed is relevant to wind only when you're figuring ground speed, as wind isn't wind powered because the glider will fly regardless of wind. So Wind-powered isn't the case as this is a glider not tethered on a FOIL, as in F.O.I.L......

if the glider have variable trim it's airspeed isn't constant it variable, So Airspeed is 400mph, or it's ground speed is 400mph.

IQ test: How fast is a RC Gliders Airspeed, if it's speed is 400mph, flying into a 40mph wind, then what's it's ground speed if it's flying with a tail winds at 40mph.

thank you good bye!

here it is simply: our speed records are tethered records, a function of kite performance, drag, and wind speed, that is wind powered.

and no, this is not hurting thy brain, just interested in physics more than most


oooo. and soaring, is airspeed + windspeed = somewhere close to -/+ 0. although once airborn and up to air speed it's likely your ground speed will increase as you crab the ridge at +/- O airspeed. hmm...but then your AoA isn't constant and the idea of adding Drag, not trim, could change the ground speed -/+ regarding above.

USA_Eli_A - 24-8-2009 at 05:14 PM

IQ test Answers:

Airspeed = 400mph
Groundspeed = 440mph
Windspeed = 40mph

Tried to get it up before anyone answered, if you want to know why, that'll cost you a spelling lesson or beer!

Kamikuza - 24-8-2009 at 05:19 PM

:lol:

USA_Eli_A - 24-8-2009 at 05:24 PM

what is the Angle of incidence?

if you don't know, it's more important than angle of attack!

furbowski - 24-8-2009 at 05:26 PM

Quote:
Originally posted by USA_Eli_A

it's actually no wind speed record, ACTUALLY NOT AT ALL EVEN CLOSE THE SAME CONCEPT!



:P

1) actually, if I could change the title to "400 mph wind exploit" or something like that, I would... but it's been funny to see the reactions to the strong wording of the topic...

2) it's posted in the most general area on the forum.

I used to sail offshore a lot, and watching albatrosses doing this in 60 knot winds and 30 foot waves was like watching the wind gods at play! It was cool to stumble across folk taking that idea and seeing how far they could go with it!

USA_Eli_A - 24-8-2009 at 05:29 PM

it is actually an amazing Air Speed Record.

did you know birds can soar moving object like waves, and travel up and down the coast from mexico to washington do so...

nice topic tho!

and you need to come to SOBB!!!:wee:

furbowski - 24-8-2009 at 05:33 PM

btw, i think most of the faster gliders have very low angle of incidence.

is angle of incidence a concern for kites? :puzzled:

WELDNGOD - 24-8-2009 at 05:56 PM

http://www.wfu.edu/biology/albatross/atwork/dynamic_soaring....

USA_Eli_A - 24-8-2009 at 06:21 PM

is called DYNAMIC SOARING.

thank you weldngod :)

A o I, yep the kite has to have one, it relates to the rider and it's,

FREE LESSON OVER

Kamikuza - 24-8-2009 at 06:42 PM

Got it thanks :)

nwsurfwakeskate - 24-8-2009 at 07:01 PM

damn! can you imagine getting hit with that thing! that would definitely put a damper on your weekend :o

its flying pretty close to the pilot and bystanders and I would imagine its probably pretty hard to keep from screwing up or loosing track of it when its going that fast!

rdavis - 26-8-2009 at 11:12 AM

Quote:
Originally posted by nwsurfwakeskate
damn! can you imagine getting hit with that thing! that would definitely put a damper on your weekend :o

its flying pretty close to the pilot and bystanders and I would imagine its probably pretty hard to keep from screwing up or loosing track of it when its going that fast!


That's exactly what crossed my mind. Awesome vid though.

rip2tide2 - 2-9-2009 at 10:00 AM

ditto - the next video up was "destroyed in seconds" - I was starting to think that this one somehow related (i.e. someone getting nailed)

bison - 2-9-2009 at 01:20 PM

Yeah, it called Slope Sailing.

I flew one on Cape Blanco many years back. Just like an RC plane but no internal propulsion. Fun, but certainly condition dependent. I flew a GEEK it was a trainer much like the ones you see in hobby shops. About halfway between a glider and powered plane design. Some guy down there makes them.

Also, 392mph is SCALE SPEED. The physics change quite a bit when the mass goes way down.

http://rcvehicles.about.com/od/basics/f/scalespeed.htm

Kamikuza - 2-9-2009 at 06:36 PM

I was going to say 'surely it's only scale mph' but they're measuring it with a radar gun aren't they ...?

furbowski - 2-9-2009 at 09:19 PM

Quote:
Originally posted by bison

Also, 392mph is SCALE SPEED. The physics change quite a bit when the mass goes way down.

http://rcvehicles.about.com/od/basics/f/scalespeed.htm


I'm pretty sure there is no scale speed involved, and there is no mention of scale on the gliders...

I clicked around a bit when I first stumbled across this, and it seems these boys are pushing the envelope of radar gun performance as well... stock radar guns can't handle the speeds involved. Also the gliders at their fastest speeds do not point directly at the gun so the readings are all a bit slow if anything...

it's an exploit, sure, and a somewhat misleading thread title (sorry), but the speeds involved are the real deal!

william_rx7 - 3-9-2009 at 09:15 AM

OK, stepping aside from the 'discussion' on what it's called or how this works.
- Thanks for sharing, never seen anything like it, always cool to see something new.
- I'd love to see this in person
- It does seem a little NASCAR-like. I mean, is it really more fun to hit 400 mph than 300 mph.
- Seems like the burn-out factor comes pretty quick.

furbowski - 3-9-2009 at 09:19 AM

Quote:
Originally posted by william_rx7
- It does seem a little NASCAR-like. I mean, is it really more fun to hit 400 mph than 300 mph.
- Seems like the burn-out factor comes pretty quick.


You nailed it, bro...:thumbup:

but yes cool to see and if I pass by some folks doing this I'd get up close enough to hear what 400 mph w/o an engine sounded like:o