Slashdot Mirror
Project OpenSky Takes Off
Jesrad writes "As was reported two years ago on Slashdot, japanese artists, students and engineers under the lead of Kazuhiko Hachiya have taken upon themselves to build a real-size, fully functional Mehve (japanese website), the small jet-powered glider flying wing ridden by anime heroin Nausicaa. They have made a lot of progress, and are now test-flying the full scale, yet unpowered model by tow-launching it along with its thrilled pilot. They're having a lot of fun, too, judging from the movies of the testing sessions."
Is anime heroin better than black tar heroin or china white heroin? I'm going to have to go to Tokyo and ask a heroine.
In think that you may have meant 'heroine' instead of 'heroin'.
Anyone who's seen the opening sequence from "Kaze no Tani no Nausicaa" (Nausicaa of the Valley of the Wind ) can understand the type of flight experience they are trying to produce here.
The freedom with which Nausicaa sails around the skies on a flying machine light enough to carry yet strong enough to carry out some hairy aerobatics has figured in many a daydream. Hayao Miyazaki takes our daydreams and puts them on the big screen.
Of course the reality of FAA regulations and principles of aerodynamics tend to get in the way of truly realizing the dreams but I give kudos to these guys for trying.
If you don't want to repeat the past, stop living in it.
Oh, I thought he meant getting sued by whomever created the anime.
Sure you can keep it up for hours. See here for a quick run down on human powered flight. Now consider the fact that a lawn mower, with it's tiny tank, provides ten to twenty times as much power as you can sustain and does it for hours on end. It's not far from there to the whole ultralight aircraft industry.
Those things are too dangerous for me but are lots of fun for those who fly them. I like something with a little more power to get out of trouble. Ultralights get blown around and where the wind blows is not always good for you.
Friends don't help friends install M$ junk.
Fuel density:
Kerosene (Diesel fuel): 11,000 watt-hours per liter, 13,000 watt-hours per kg
Typical ultralight engine: 30,000 watts
Assuming you are running at full throttle all the time (fairly unlikely):
a 10 liter tank will last you 3-odd hours and weigh right around 12 kg. Most ultralights have a fuel capacity between 8 and 35 liters.
Does the math work out better for you now?
I had seen their previous RC models -- which really didn't look too much like the glider from the movie -- and thought "OK, that's pretty cool".
This is lightyears beyond cool.
They are fighting a lot of aerodynamic issues to make a human-carrying glider that now looks remarkably like the one in the movie. The challenge in flying wings is to fight the tendency of most wings to pitch down. In addition to this natural tendency, this wing has two things going against it.
1) The "jet" causes drag below the CG
2) The person raises the CG so high that there is a tendency to be unstable
Add to this the fact that the design allows very little sweepback (a typical way to get pitch stability in flying wings (see B2 and Northrop)) then you are really in a bind.
They must have a fabulously high positive pitching-moment airfoil. It is possible to make reasonably efficient airfoils with some positive pitch moment, but unless they've invented something truly revolutionary -- the demands on this airfoil for stability might mean that the glide ratio would not be very good.
Still -- unbelivably impressive. Way to go!
Thad Beier
I love Mondays. On a Monday, anything is possible.
Anime heroin is two parts narcotic, one part soul of the forest, and one part nanobot. Somebody told me they were starting to put in ground Pikachu, but who could harm that little thing? Except Mew Two, that is.
Q: What did the comedian say to the crowd?
A: If I knew, this joke would be funny.
The result is that homebuilt aircraft are more likely to have safety features (e.g. modern auto engines,
Gotta stop you right there. Automobile engines and aircraft engines are very different beasts for very good reasons. Automobile engines normally run at 20% of rated power with occasional bursts to 80% rated power and only the rarest burst to 100% rated power. Aircraft engines normally run at 80% rated power and will routinely spend several minutes at 100% power during each flight (takeoff and climbout). That critical "expected normal load" results in a very different engine design.
If you try to put an automobile engine in an airplane without substantial redesign to account for the different expected loads, you're basically guaranteeing premature catastrophic failure.
The result is that homebuilt aircraft have as good a safety record as commercially built designs.
Check your facts. Homebuilts have a much higher accident rate per flight-hour. Still pretty low, though.
Regards,
Ross