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More On Silent Supersonic Planes
Reverberant writes "Popular Science describes the latest attempt at developing a supersonic plane designed to minimize sonic booms. The article describes some of the history behind the research, and recent attempts at validating the theory. Also note that researcher Ken Plotkin is a frequent contributer to alt.sci.physics.acoustics."
Where is that Hedgehog when you need him? Can't we tell him just to be quiet?
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REAL Friends help you move dead bodies... ^_^
Conjugate much?
is it just me being paranoid, or is not having any windows and having cameras send external images to the cockpit a "bad thing." obviously, without computer systems, the planes are almost useless, but if anything happens to the camera, the pilot can't even *see* outside the plane.
BSD is for people who love UNIX. Linux is for those who hate Microsoft.
If it's been published on the prestigious trade journal 'alt.sci.physics.acoustics', it must be true!
Since when has this country used intellectual elite as a pejorative term?
Pilots rely on more than just being able to see outside. They have literally dozens of instruments that they have to monitor in addition to the view outside. During the night and over the ocean, you have nothing but your insturments to rely on, so it's not like this is a new thing for pilots. Still, if it were ME I would want a window :)
"Popular Science." No such thing, man. More like, "nerdular nerdance."
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That's very interesting, but would not it make more sense to make the normal, subsonic planes more silent? They are much more in use, and the noise causes a lot of grief near airports, especially at night. Here in Brussels, this problem is already for years on the political agenda, being a very difficult problem to solve (economics vs. health...), so silent planes are really a must!
I've never heard a sonic boom... so I'm not really sure how loud they are, but a co-worker described it as "pretty much sounds like thunder".
EVERYONE has heard a sonic boom at one point: the crack of a whip. That sound you hear is not the tip of the whip hitting anything. It's the sound of the tip accelerating beyond the speed of sound and creating a mini-sonic boom. That little flick at the end causes the tip to snap out at incredible speed.
Now as far as a big sonic boom, I haven't heard one either. I'm sure there are some pretty strict regulations about not creating sonic booms in civilian areas.
GMD
watch this
I am almost certain that people wont want it flying over their neighborhoods. I can remember watching a show about all of the hubub people made about the Concord landing at their local airport. You would have thought the world was going to end!
Then, once they heard the landing (which wasn't any louder than a regular plane landing), they went back to their caves and silently watched the news for another issue to get their panties in a bunch about. *sigh*
The research airplane in this experiment failed to reduce the sound of the sonic boom as much as hoped.
In fact, this research is primarily intended for the next generation business jets , not the military. The future of such planes is up in the air in the moment, because not only do they have to reduce the wake of sonic booms (they shatter windows and suprise people), the regulations have to change. I for one know that the FAA is slow at that.
Regarding the need for windows in airliners: A Boeing 777 pilot today needs to be able to see a few hundred feet ahead of him on takeoff, but after rotating off the runway, he doesn't need to see anything at all. Modern airliners can land and auto-flare... that is, land themselves in ZERO visibility conditions. The pilots undergo extra training for this, of course.
FAA Certified Flight Instructor
A sonic boom can also be detected at many miles distance by a wired or radio connected listening device, analyzed in a few seconds to get a fairly good idea of what sort of plane emitted it, and that information sent to the potential target, or interceptor forces, at the speed of light or close to it, long before the plane can cross the terrain to get to its target. The Soviet Union was deploying such systems in the early 1960s, and it's a fair bet that even some "third world" countries have their own variants on them today.
Who is John Cabal?
As the very first paragraph of the article mentioned, one use is for supersonic business jets. Just because the researchers are using a heavily modifed F-15 as a test vehicle doesn't mean it's all for killing things. NASA still uses Titans for launching spaceprobes, even though they were originally designed for launching nuclear warheads. The planes that fly through hurricanes to gather wind speed data probably save lives every time a big one approaches land, but they are still modifed military aircraft.
Yes, this has military applications as well. Lots of things do. The medical resarch you mention has been perverted to war before, for just one example. If you would like to see this knowledge focused on peaceful persuits and shared for the benefit of all, more power to you. It is not going to be possible to share it with businesses across the country and still keep it a military secret. All you have to do to help mankind here is pressure the people talking about applying it to silencing commercial aircraft to keep that promise, and it will make things better for lots of people.
Who is John Cabal?
correct, but the Concorde didn't ordinarily use afterburners; it had them only for the greater thrust demands at take-off and during acceleration, not for cruise. it was an expensive plane to run largely because of its low seating capacity and short range, which barred it from many of the lucrative trans-Pacific routes.
(some have also argued that the low-to-nil bypass ratio of the Concorde's Olympus engines made it more expensive to run. that may be true; i don't have any really convincing evidence either way.)
that would have had to depend on what the plane was doing. during landing, i can well believe the difference might have been small; during take-off (under afterburners, natch!) that would very much surprise me; and while supersonic, absolutely not.
Concordes were politically acceptable so long as they stayed subsonic over land, so nobody would complain about the boom. they were also hideously expensive to run, which in a more rational world might have shut them down all by itself, but apparently there were enough eccentric ultra-rich people to keep them flying for decades in spite of that fault. no amount of money, however, would let them reamin at their designed cruise speed above anyplace people lived, and that was as much a political shortcoming as a technical one.
That's not really true, it's just that most of the changes are more subtle than the flamboyant extravaganza that was Concorde. The newer planes are doing much the same job they did back in '99, but much more efficiently and safely. There's little "Gee Whiz" factor, but technology is sure marching on.
There's more than just technology involved too. I remember an article on Beyond 2000 about BMW's Hydrogen powered 7 series. The technology has been around for decades, but we don't have this stuff on the road due to politics and infrastructure. When the need arises (when the cost/benefit ratio is right) it'll happen. Hopefully all the world saving technology will hit the mainstream before it's too late for the planet.
Disclaimer: Saw Micheal Moore's "The Corporation" the other day... ;)
Forget thrust, drag, lift and weight. Airplanes fly because of money.