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Supersonic Flight Without The Sonic Boom
fname writes "Here's a story from Spaceflight Now about a new test aircraft that can travel at supersonic speeds without triggering a sonic boom. The technology works by modifying the shape of the plane. Although it's been believed to be possible for a long time, this is the first actual flight test, barring black box projects I suppose."
What does Guile think about these developments?
Never lived near an airbase, eh?
Besides, would you want your military aircraft alerting everyone for miles of your presence?
It makes it more practical to have supersonic travel in and around cities, which are notoriously noise sensitive. In the past, the routes for such planes were quite limited. Now, if the cost drops, perhaps we'll see them more in the mainstream.
Oh, and there are likely military applications, as well. Anything to reduce chances of someone hearing you coming can help (although, most times, these planes take off far from their mission).
There's supposed to an Earth shattering kaboom?!?!
evidently, you can't read...
"They foresaw a way to solve the sonic boom problem, and to enable a generation of supersonic aircraft that do not disturb people on the ground."
It seems it merely muffles the sonic boom. The technology doesn't completely silence it.
First paragraph:
My Karma: ran over your Dogma
StrawberryFrog
It is felt that the SST movement (i.e. concorde) was derailed by the american plane maker (i.e. Boeing) which got enough lawmakers to say that the concorde could not fly over the USA (i.e NY to LA) because of the sonic boom.
if a SST can go supersonic without the boom, then development of new craft could take place, because new markets could open up...
The article states that the boom is reduced because the merging of the pressure waves does not combine into a shock wave(s) as readily.
There is still a sonic boom.
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This is important because the main reason super sonic airplanes are not used more often for civils is because of the sonic boom. The sonic booms can be very loud and disturbs urban areas. The Concord, for example, had to wait to be very far away from populated areas before getting into super sonic speeds. This rwas costly, since the Concord was design to have optimal fuel efficiency at super sonic speeds.
"There is no teacher but the enemy."-Mazer Rackham
Wh00t! Now I can run outside and not have to worry about being blown through my house by a sonic boom! Now if we can just do something about those G5s...
The nature of sonic booms is that the plane comes first and then the sound. To be "supersonic", the plane has to be faster than the sound it makes, remember?
Most countires (including the U.S.) have banned overland supersondic flight due to noise problems.
Not having a sonic boom will open the door for over-land civilian supersonic flight.
Just think. Los Angeles to New York in 3 hours.
The noise problem is one of the major reasons supersonic passenger aircraft never took off. The Concorde, for example, is simply not allowed to fly to most potential destinations, due to the noise levels.
And, well, yes, not using up energy to produce an impressive bang certainly improves energy use somewhat; that is not the reason for this developmen, though.
Trust the Computer. The Computer is your friend.
It just modifies it so it isn't as annoying. (Spreading the force over a larger area.)
Very useful, yes, but you would still hear it going overhead. (Though I suppose the 'boom' fades as you move away from the plane, and this could speed that up...)
'Sensible' is a curse word.
When supersonic tests were going on, people in the midwest got real tired of all the booms that spooked their herds and rattled their homes
Ever wonder why the Concord only flew at supersonic speeds over water, and not land? Because they couldn't - it's too disruptive. A supersonic craft without a sonic boom would enable flight over land.
1.) Military people can have fast jest (read "attack planes") that don't alert the person on the ground (read "those who aren't killed by the bomb that will be dropped on them") as to whether there is a jet above them.
2.) One of the biggest problems with commercial super-sonic airlines is that people didn't want them flying over their house (the major reason such flights were primarily only over the Atlantic Ocean). If the sonic boom didn't exist, presumably people wouldn't be as adverse to such a situation.
That being said, the article doesn't indicate that the sonic boom is gone, it indicates the sonic boom is not as loud. In fact, the article states that they had to compare a "traditional" sonic boom to the "new" sonic boom to verify that there was a change... It seems a big step, but not to the finish line.
Right, but it still alerts everyone in the area once you pass, so they can be more trigger-happy when the plane is returning home...
This is early 1990s technology.
Aurora has had this incorporated since the beginning.
But then again, I'm drunk and saying too much. So ignore all this.
I live near the airbase, and I'm talking on the telephone to you (miles away). You'll hear the boom before you see the plane!
The reason to do this is to allow supersonic transports to fly over inhabited areas. The sonic boom from the Concorde, for example, is shockingly loud, it would never be tolerated.
What the article doesn't say, but was reported in Aviation Week a few weeks ago, is that this technique (and certainly this airplane) only reduces sonic booms -- it doesn't eliminate them. This demonstration is to show people that the math is right; that the sonic booms can be reduced through shaping. It is still unclear whether it is possible to build a practical airplane with a tolerable (negligible) sonic boom. Perhaps this could be combined with other techniques (the Russians have been working with exciting a plasma in front of the airplane, for instance) and together you could get a minimal boom.
Probably the parent article was questioning the need for supersonic travel at all -- whether it's worth the cost. It will almost certainly be less fuel efficient than subsonic travel. Travel in general is less fuel efficient than staying home. Living is less fuel efficient than dying.
thad
I love Mondays. On a Monday, anything is possible.
I happened to notice a show (On The Edge) on the Discovery Wings channel covering a lot of this. Not as in depth, of course, but interesting nonetheless.
Now all i need is a way to reshape the bullet in-flight for my high powered rifle and presto, the perfect assasination ;)
This comment does not represent the views or opinions of the user.
Because quite a few larger cities have sound restrictions that will not allow sonic flight within a certain distance of the city. It was this restriction that limited the airports that the concorde could fly into and out of.
... that the vision of supersonic flying cars didn't float through your mind when you read the article :)
So, when can we throw out the Concord and whatnot and get transcontinental supersonic flight to boot?
> Just think. Los Angeles to New York in 3 hours.
What!? I've been getting about 120ms average.
The unofficial
In related news, real estate prices for residential property located near military airbases just jumped by 10%.
It then plummeted by 20% as investors realized that this technology was just in the prototype phase and unlikely to be implemented on a large scale for decades.
Unfortunately, the article never reveals how much they have reduced the sonic boom.
But, this could be great for supersonic transports if the design technolgy is used in future designs. It would mean that we could have supersonic flights from NY to LA lasting only a couple hours! If the noise was reduced enough, the FAA would let them fly over populated areas (like the continental US)
har har _____
I would really like more infomation on this, that article was incredibly short and left me with many questions. Mostly, how are the shock waves being broken up, and how would it affect the drag (ie, would it be a better design for watercraft also?)
But then again, it is a government project, can't expect much in the way of information.
___________
"Build a man a fire warm him for a day, set a man on fire and warm him for the rest of his life."
surely you meant "black ops", no?
Uhh...no. Your story is refuted by the fact that the Russian program (which would have suffered none of the enivronmental concerns of the Boeing and Concorde efforts) failed as well, despite being hugely helped by data stolen from the Concorde's testing. The Russian SST died when their test plane crashed horribly at the Paris Air Show. Despite the Russian air fleet's total lack of interest in passenger safety, the Air Ministry decided to kill the project.
The big barrier to SST success has always been economics. It's incredibly expensive to fly faster than sound. Boeing had a quite successful SST program, but cancelled it when it became clear that SSTs would not be economical. Concorde never made money for either of its parent airlines, despite the incredibly expensive tickets for the flights for which it made any sense at all.
Because we all know how annoying those sonic booms are that keep us up all night.
Hmmmm. That must be how the UFO's do it.
Submited on september 6, 2003:
Northrop, working with the Pentagon and NASA sucessfully tested a "quiet" supersonic flight wednesday at California's Edwards Air Force Base. In the tests, an F-5E aircraft with a modified nose section flew supersonically through the test range, shortly thereafter, an unmodified F-5E flew supersonically through the same airspace, with the sensors showing a clear reduction in the intensity of the sonic boom produced by the F-5E modified fuselage.
You can't take the sky from me...
oh brave new world, that has such people in it!
The Concorde was also removed from service because of its limited availability, due to ticket costs, its aging fleet, and its travelling through the Ozone layer. The first two would have to be fixed before SSTs became mainstream aircraft.
More than enough BS
Not every technical advancement needs to be in better energy conversation. This will greatly help with noise pollution and lead to faster commercial plains in the future. Running a subsonic airplane will on the average will use less fuel then an supersonic one and supersonic plains will increase air pollution. But at least it is not making every bison in the midwest going deaf after a bunch of booms that break their eardrums. Sometimes the need for speed is more important then fuel consumption. (Think about an ability to quickly transport a Heart of Liver from a downer in CA to NY much quicker. Heck if I was that Guy In NY I would love to have it flying to me at supersonic speeds compared to subsonic.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
Sonic booms can be a helluva lot more than just "loud" or "annoying." They can implode outbuildings, knock shit off shelves, break windows... and toss around house trailers like a blast from a hurricane.
In fact, the article states that they had to compare a "traditional" sonic boom to the "new" sonic boom to verify that there was a change.
Yes, it's called "having a control". They measured them both to see the difference. It's common sense.
Not to troll you or anything, but when you move faster than the speed of sound you arent worried about them hearing you couse youll be long gone. (you pass them before they hear you)
Anything to reduce chances of someone hearing you coming can help
Hmmm, I think the likelyhood of someone hearing you coming is already pretty small IF YOU'RE TRAVELLING FASTER THAN THE SPEED OF SOUND.
No boom today, boom tomorrow, there is always a boom tomorrow. What?! Look somebody got to have some damn perspective around here. Boom! Sooner or later...BOOM!"
I don't think Boeing worried at all about the Russian programme. The Russians were not about the buy Boeing planes, nor were about to sell SST to American carriers for the NY-LA route. Boeing's only worry was the English/French Concorde concertium (sp?).
would it be a better design for watercraft also?
Judging from the picture, the design borrows heavily from that of watercraft. The bottom of the aircraft has been modified to the point that it resembles the hull of a boat of personal watercraft.
I suspect that it works very similarly to the way that planing hulls(no pun intended) work. Just as a boat's hull spreads its wake outwards from the sides of the hull, this aircraft design likely spreads the aircraft's wake out to the sides more than straight down. This would reduce the pressure wave below the aircraft. I am confident that if the sonic boom was measured from the side on the same plane with the aircrafts altitude the sonic boom would be the same as normal and possibly more intense.
Thats OK, SEGA went the way of the dodo a long time ago.
looks like new use for the old flying boats...
SCO claims to have the copyright on SCOnic...oh wait.
Note to self: get smarter troll to guard door.
I love the headline posted here at /.:
;-)
"Supersonic Flight Without The Sonic Boom"
Which is a complete lie when you read the first paragraph of the article stating that they simply reduced the boom created, not eliminated. Fox News' web site does this too.
There is NO way to eliminate a sonic boom as long as the aircraft has either mass or creates friction. It is very doubtful that they are close to creating a massless, frictionless airplane
Getting 1/4 of the MPG per passenger compared to a subsonic plane also had something to do with it. The extra cost for fuel alone is going to double the price of most airline tickets.
That means you're in a niche market, which reduces the number of customers and impacts economy of scale. This increases maintenence costs and R&D and manufacturing overhead to very high levels. That's how you get $10,000 one-way fares across the Atlantic on the Concorde.
To compound the problem, most domestic flights just aren't that long. If you take a 1500-mile trip that needs a connection (as many do with the hub-and-spoke system), it can easily take you 9 hours to get from your home to your destination address, and only about 3 of those hours is in the air. An SST would cut that trip down to 7-1/2 or 8 hours at the cost of 4X the fuel usage. It just doesn't make any sense on the vast majority of flights.
Now if they could just make some computer fans that were quiet. I really hate the sonic booms that come out of them when I power up my machine.
Invalid Checksum. Retrying.
The future of ultra fast transit isn't in airplanes gliding along, masking their sonic wake. It's with things like multi stage trans-orbital aircraft. A plane could take off using standard jets until it got to the maximum height the jets could support. Then switch over to SCRAM jets and break for the outer atmosphere. Even the prototype SCRAM jets today are capable of flying at many multiples of mach. It just takes the energy to get a plane beyond mach 2 (or so) to begin with. If you stay at the edge of the atmosphere, the very low pressures create little drag compared to today's cruising altitudes. Also, the higher you are, the faster you must go in order to create that critical pressure point. You don't need to totally leave the atmosphere; in fact it's easier that you don't. You won't have nearly as much heat to deal with as reentry, and you won't have to add rockets or thrusters to maneuver in low orbit. Imagine flying form New York to Tokyo so fast that food service isn't needed.
I hate how petty and arbitrary the editors can seem to be... Your summary is better than the one they accepted...
The article didn't say exactly how great the reduction was. If they didn't explicitly mention the magnitude of the reduction then it couldn't have been that spectacular. Looks like they want publicity that they've had some (small) initial success so they can get more funding.
Anyways, jet engines with the thrust to get these craft supersonic have supersonic exhaust and are extremely loud anyways. A jet engine is a standard measurement when discussing/teaching what sound decibels are. A jet engine is way louder than the loudest rock concert. It's usually the loudest thing on such comparitive decibel scales. Even if the aircraft could be made silent, the engine couldn't.
What do you mean by saying that the soviet program would have suffered none of the enivronmental concerns of the Boeing and Concorde efforts?
The soviet plane was just as noisy as the others wasn't it? Also the soviet program died the same death as the more recent boing program when they realized that it was too much of a fuel hog, even more than the concord, to be usefull. There was even a proposal between the soviets and the british to export the more efficent european fuel control system to the soviets but that was blocked. It didn't die because of an airshow accident, that was just the last straw.
You don't need to throw it out, it just needs a nose job. Witness:
Honk, honk!
You only want to throw the thing out when maintaining it costs more than developing and buying a new one. While it might be hard to modify the concord's swiveling nose this way, it's worth looking into.
The next modification needed is to the law, so that flights that don't make too much noise can fly over the contenetal US. If you can get from New York to California supersonically, people will want to do it and will pay for the above mentioned development and building.
Friends don't help friends install M$ junk.
Please please enlighten me on how reducing loudness = no sonic boom?
Gay. Gay. Gay.
Was it entirely necessary to bring your rebuttal down to a middle-school level, by including that last line?
Win dain a lotica, en vai tu ri silota
That can serve as my wallpaper for a bit.
...how are people supposed to admire the speed of a plane when there is no sonic boom? All the sensation is lost :(
You know, for some reason or another, the plane reminds me of Richard Nixon.
how loud is a sonic boom? And how much less with this new tech?
Now they'll have to use old planes in the movies, or fake the sonic boom through sound fx.
home
now under special conditions the sound waves all pile up making one giant pressure sheer, the shock front.
to the extent that you can disperse the shock front then the boom is indeed disperesed. You have not however eliminated the energy dumped into the air. But the "boom" is gone.
that's what this article is saying I beleive.
The really cool part of this is that its like to old adage about genius taking many steps. first everyone believes that something cannot be done. then some fool shows it might be not be impossible. then a scientist shows it is theoretically possible, and finally some engineer shows how to do it. Then it seems obvious
now that we have crossed the threshold of knowing that its possible to break the sound barrier without a sonic boom we can now get on with wondering if maybe the remaining waves could be modified in other ways, like directing all the sonic energy up and not down, minimizing it or maximally dispersing it. its now on the table.
It reminds me of discovery of negaitve index of refraction or of "optical bullets". At a certain optical power density the plasma of electrons stripped from air creates a non-linear lens that focuses a light beam in both time and space down to a stable optical pulse that neither diffracts nor diverges for macroscopic distances (hundred of meters till it runs out of energy). Now that is pretty weird since if you ask anyone who knows anything about light they will tell you that the two most fundamental proerties of waves propagation in media are dispersion and diffraction. Thus optical bullets are a form of electormagnetic farfield propagation that is not like a light wave. Negative index of refraction destroys another myth that light cant be focused smaller than a wavelength without non-linear methods.
so now we have yet another wave propagation myth falling, that when the speed of an aobject passes the wave speed in the media that a shock front is created.
just to go off on wacky extrapolation for a moment, I will point out that there is a close connection between the idea of a shock front and the idea that faster than light travel is impossible. Perhaps we can disperse that "light cone" and bend time some day.
Some drink at the fountain of knowledge. Others just gargle.
"When you can measure what you are speaking about and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of the meager and unsatisfactory kind."--Lord Kelvin
The article doesn't give one single blessed number that would enable anyone to judge how effective the experiment was.
I'm not sure what the right measurement would be... decibels? sones? psi? pascal-seconds? Or average blood pressure increase in human subjects in Hgmm? But the article doesn't say.
Not even the usual marketing claim, like "42% less boom than traditional aircraft, yet still has that same great NASA 'look'"
Something about "We were all blown away by the clarity of what we measured" just doesn't do it for me.
"How to Do Nothing," kids activities, back in print!
In fact, the article states that they had to compare a "traditional" sonic boom to the "new" sonic boom to verify that there was a change...
..you expect them to test this thing and not measure the decibels??
Umm
I just travelled back in time to make the parent of your post! Ha.
G5 too fast? just run Bochs and emulate windows.
That's why pelicans are so fast!!!!
You are not the customer.
On the contrary, my guess is these low-noise jets will be even bigger gas guzzlers than normal supersonic jets, for three reasons.
1 - Fuel efficiency wasn't mentioned in the article. If it were better, I figure they'd be bragging about it.
2 - Apparantly the main advancement that they did was to have the air heat up near the nose of the aircraft, to make a smooth pressure gradient. Now that heating must come from friction, which takes energy (quite a bit when the air is rushing by at Mach 2).
3 - Current aircraft are designed with loads of computer aerodynamics modelling, with the main design goal being low drag (ie., high fuel efficiency), so if reducing the sonic boom reduced drag, it already would have been discovered and implemented long ago. In subsonic aircraft, design improvements of 0.01% are fairly typical and worth going after, as this is a very mature field of engineering.
I guess we can forget about those 4 hour NYC to Tokyo flights for the time being.
... my CPU fan? Now that's a silencing challenge that will make money.
"Consensus" in science is _always_ a political construct.
Your story is refuted by the fact that the Russian program (which would have suffered none of the enivronmental concerns of the Boeing and Concorde efforts) failed as wel
Your logic is refuted by the fact that Concorde was in service for almost 30 years -- it carried its first passengers in 1976. The technical failures of the Russian project have no bearing on Concorde.
in fact the original poster has a good point. Concorde failed to flourish economically largely because the US authorities refused it permission to fly supersonically over the continental USA. That meant it was automatically excluded from the longer routes, such as London-LA, where the timne difference from supersonic speeds would have made a revolution in business travel possible.
Even on regular jets it's possible to make it to NY and back on business in 24hr (leave London 9am, arrive NY around 11am, afternoon meeting, leave NY 10pm, arrive London 9am...) Concorde's extra speed on that route is basically just adding convenience and glamour. But London-LA in 3 hours instead of 10 would revolutionise business travel between Europe and the west coast. That's what BA and Air France were counting on to make the numbers work. Another result of the FAA ban on supersonic travel was that US airlines, naturally, would never buy the airline.
So basically, the FAA ban on supersonic travel in the US meant that Concorde was barred from its most profitable routes, and so was unattractive to most airlines. That's why it never made any money, either for its makers or for BA and Air France. And there's little doubt that the FAA ban -- while partly based on genuine concerns about noise -- was also in part a response to protect the US aircraft industry.
It's just ironic that the long-term effects of this strategy were to kill of Boeing's Sonic Cruiser, which it had pinned its hopes on as the airplane to beat Airbus (the descendant of the consortium that built Concorde). As a result, Boeing is reduced to relying on the 747 -- first flown in 1969 -- to compete with Airbus's new superjumbo.
The author of this post asserts his moral rights.
A sonic boom isn't a one time deal when you crack the sound barrier. after you break it, the boom is continous as you fly over the ground. Thus if you travel supersonically over the entire width of texas, then the entire width of texas for that corridor your plane passes over will hear/feel the shockwave.
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Wow, you sure put a lot of effort into that reply. It must burn you to know that Karl S. Kruszelnicki Pty Ltd had the gall to blatantly plagiarise it and copyright it, no less.
It all goes downhill from first post
Dude, parsing your paragraph was a lot of work. You are letting the grammar and spelling slide too much - they do kinda matter, and i'm not a pedant.
A month ago a F4 went supersonic in 11000m height in the area i live. Actually, it traveled 200km west to east through north bavaria.
I can tell you "boom" is a light understatement...
I grew up near an infantry test area and im quite used to RPG explosions in the distance ect.
I was standing near an open window and could feel the pressure. It was like back in the army if someone detonated a practice handgranate and your earplugs filter out the high frequency noise.
I read in the paper the next day that hundereds of people called the police believing there was some kind of bombing...
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
On planes such as the 747, this is offset by the large load of passengers you can carry. In a supersonic jet however, you are limited by the shape of the plane. The concorde carries very few passengers as its fuselage is VERY narrow. At this point in time, its simply much too expensive to fly a fleet of supersonic passenger jets.
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"Here's a story from Spaceflight Now about a new test aircraft that can travel at supersonic speeds [with a lessened sonic boom]. The technology works by modifying the shape of the [sonic boom]. Although it's been believed to be possible for a long time, this is the first actual flight test, barring black projects I suppose."
Or they could use any of the current or still in development aircraft that still produce significant sonic booms.
http://science.slashdot.org/comments.pl?sid=77565& cid=6895042
It is LOUD. Its not like the long fading sound a subsonic jet creates, but a short "hit" of sound, like a gunshot, but with lower frequences.
Thing of a bomb detonating 200 meters away or a single bass beat from love-parade class speakers inserted into silence.
A story i cannot verify is that in the early 80s a pair of tornados practives ultra low altitude "vallay crawling" and something went wrong.
One pilot needed to gain altitude fast because he left the cloud layer facing a hill slope.
He used the afterburner and broke the sonic wall only a few hunderd meters above a village.
They hadn't got much unbroken windows after that and the church had suffered cracks a few centimeter wide in its ceiling.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
After reading just the first paragraph I could tell it was taken from somewhere else, no one writes like that in a damn slashdot post. It's always gratifying when someone knows where it came from and links to it though... makes the original poster look like that much more of a fucker. :)
Joseph?
A reduced sonic boom has obvious civil purposes, but the aim of this program is to improve the designs of military aircraft. A reduced sonic boom would make supersonic aircraft in enemy airspace less noticeable.
Of course aircraft cannot be tracked using aural emissions, but it only takes sound to wake up an airbase full of sleeping pilots or snoozing radar operators...
Article says " the loudness of the sonic boom is greatly reduced" (my emphasis), "We were all blown away by the clarity of what we measured", "Comparison of the data confirmed the modified shape of the test aircraft altered the sonic boom as expected" ... and, in case you are thick: "Repeated tests verified these results".
But it never says what the results were! Did it reduce the "loudness" by 10%? 50%? 90%? Using what kind of weighting?
Balderdash. The great circle route from Seattle to London passes over the North Pole, and need never cross land. Why didn't Concorde ever fly that route?
I suggest that it was because the Concorde was a fuel-guzzling white elephant.
So? Many people would pay more than double to fly NY to LA in halve the time. Or Europe to LA with a stop in New York in 7 hours (instead of >11 hours non-stop).
Lars T.
To the guy who modded me down from perfect to terrible Karma - Apple haters still suck
Don't moderate it, if you don't think it's funny, but in any case don't moderate it the wrong way!
This is simply the most amazing thing I have ever seen. A bunch of civi's were on a naval ship when a hotshot pilot buzzed the ship at supersonic speed. One of them happened to get some amazing video of the pressure wave.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
People who would pay this price are already saving more time end-to-end than an SST airliner would save. They do it by flying private business jets on their own schedule between small airports which are uncongested and near their destinations.
Yeah, what's a "Heart of Liver"?
Simple. You install a larger diameter fan at lower RPM to move the same CFM with less noise. The big problem inside a computer is how to mount it.
Your description of smoothing out the N is just another way of saying the pressure sheer of the boom is dispersed. which is what I said in other terms.
I wasn't talking about people who wanted to go from New Brunswick to Sacramento, I was talking about people going from NY to LA. And they would pay much more than double the price.
Lars T.
To the guy who modded me down from perfect to terrible Karma - Apple haters still suck
Here, I fixed his post for you:
Not every technical advancement needs to be in better energy conservation. This will greatly help with noise pollution and lead to faster commercial planes in the future. Running a subsonic airplane will, on average, use less fuel than a supersonic one - and supersonic planes will increase air pollution. But at least it is not going to make every bison in the midwest go deaf after a bunch of booms break their eardrums.
Sometimes the need for speed is more important then fuel consumption. For example, consider having the ability to quickly transport a heart or liver from a donor in CA to NY in a fraction of the time. Heck, if I was the donor recipient waiting in NY, I would love to have the replacement organs flying to me at supersonic speeds instead of merely subsonic.
Kids these days just don't seem to realize that my internet is just as powerful as theirs ;)
If they find something to plagiarize from Google, searching for nearly any unique phrase will find it just as quickly.
It all goes downhill from first post
I just noticed something with the nose.. it looks a LOT like the front of a boat. that's probably how it disperses sound waves.. I'm probably wrong, but it looks that way.
I believe it's possible to eliminate the major side effect of a sonic boom, to the point that in lay parlance we will have aircraft that do not generate a sonic boom.
If you can manipulate the shockwaves and bowfronts trailing a plane in such a way that they interfere, essentially producing low energy zones at the appropriate distance, and then redirect the rest of the sonic energy to disperse and spread out along a larger surface area and upwards into empty space, you can create supersonic craft with subsonic noise signatures.
IE, the noise the craft generates is self canceled at exactly ground level: Fly higher, and you hear a supersonic rumble, fly lower, and you hear the supersonic rumble; bank, turn, or make any maneuvers, and you hear the supersonic rumble. The rest of the shockwave will necessarily get quieter as it travels farther from the plane such that by the time they reach ground level they are essentially 'quiet'.
GPL Deconstructed
Supersonic vehicles actually generate two booms- one for the nose and one from the tail- that's why this has the nose glove and the modified tail.
Incidentally, the size of the boom is related to the size of the aircraft, military planes are much smaller and hence give much less problems.
Interestingly, Concorde's nose is sharp- this is aerodynamically efficient, but generates bad sonic booms- it would be much better to use a rounded nose from that respect. Detailed changes to the tail section (other than the ones shown here) can also greatly reduce the shockwave. If you've seen Thunderbirds, some of the airliners shown there are strongly reminiscent of the kinds of shapes that probably help out, (strangely enough, that's probably because they got fairly good advice when designing their models.)
I think that the vehicle shown in the photo has a compromise nose shape- it's sharp on top to give better aerodynamics, but rounded underneath to project a weaker sonic boom downwards. Atleast that's my take on what they've done- IANAA. (I Am Not An Aerodynamicist).
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"It doesn't matter, a geek forum or a fortune-500. People are the same. They love their friends. No matter that it may sacrafice the quality of their business.
Less is more !
The real question here is, how can we turn this into some sort of weapon! Boo-yah!
Proverbs 21:19
Do bombs hit the ground faster than the speed of sound?
Funny you should mention that. When I was a kid I saw the movie Firefox. Briefly, an American agent steals a Soviet Mach 5 plane. While escaping said agent flies low over the ocean, producing such an effect. This article reminded me of this film. I recall, when I saw the spray, thinking "Jeeze Louise, that's friggin' awesome." That's the only part I remember about the movie all these years later. It wasn't so good otherwise. If you don't mind B acting and vintage 1982 special effects though, it may be worth a look.
For those who have asked how much of a reduction in sonic boom was achieved:
The following URL says the peak pressure was reduced by one third, but there was very little difference in the sound of the boom on the ground. This was a better result than expected, since they did not expect to hear _any_ difference.
After all, this was _not_ an attempt to fly supersonically without generating a sonic boom, despite the misleading title of this thread. Instead, it was a (very successful) attempt to valid the CFD models used to design the aircraft nose modifications and predict the reduction of the pressure wave on the ground.
Now that they have proved that their method works, they can work on more noticeable reductions.
http://209.157.64.200/focus/f-news/973267/posts
Had sex whenever I wanted it.
Suck it, babydoll...
It seems to me that this is the way that ultrasonic planes should have been built in the first place. The concept is so simple that I knew what the whole article would be about after I read the title of the summary.
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The "N" wave is caused by a high-pressure spike at the nose and a low-pressure spike at the tail. A shorter aircraft would have the two extremes of pressure happening much closer together, increasing the effects of the sonic boom. A longer aircraft such as Concorde results in a small but important delay between the two pressure extremes, to the point that they are usually distinguishable as two separate and somewhat reduced booms instead of one large one.
You actually CAN remove the supersonic boom, by using what is called "Magnetohydrodynamic". By surrounding an object with a fluid conductor (like a plasma), you can induce movement to an object without making him break the sound barrier, even if it fly way over it. This would be a good explanation of some "UFO" sight (American testing this theory), since plasma gives an multi-colored shape around the object. This could also be used in salted water, to move submarine to unprecedented speed, even more than in the air! You can find some of the experiment and the actual theory if you search for "Jean-Pierre Petit" and magnetohydrodynamic (MHD), and probably many others sites.
Here is the link where you can find information about what I just say before : http://www.jp-petit.com/science/mhd/m_mhd_e/m_mhd_ e.htm
Well, the 767/777 routinely fly as high as 41,000'. Lear and Gulfstream both reach into the mid-50's.
Concorde didn't actually spend much time at 60,000. A typical trans-Atlantic flight would start at 45,000 and then slowly climb as fuel weight was reduced, with only the last hour of supersonic flight above 55,000'. In the first half of any transcontinental flight it would be in the way of quite a few aircraft.
FWIW, the U2 is really the least of Concorde's problems as they generally fly between 65,000 and 70,000', well out of reach of Concorde.
I think we also need to think in terms of scale/distances. Just because you're faster than sound doesn't make you faster than light or electricity/communications. When you're a country as big as the Soviet Union/Russia for example, presumably if your border posts start reporting hearnig sonic booms, all the major airbases smack in the middle of the country will have some warning they wouldn't have had otherwise and would be in a heightened state of alert just as your plane approaches?
The Concords noise problems had more to do with takeoff and not supersonic flight.
The engines that the Concord used where turbojets not the turbofans that airliners use now. To make matters worse the Concord used afterburners for take off. The amount of noise that that an afterburning tubojet makes compaired to tubofan of the same thurst is huge.
To not make a sonic boom over land is easy. Just do not fly supersonic. THe trick is to make an engine that is efficent at supersonic and subsonic speeds and that does not make too much moise or pollute too much.
Good luck.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
This design will likely have higher drag than traditional supersonic aircraft. The designers cannot get around the fact that the air cannot move out of the way as quickly as the oucoming aircraft passes through it. Its just that instead of all the air piling up into a massive shockwave, it is distributed into a more gradual shock front that will be less perceptible.
The supersonic area rule tells designers how to minimize drag by shaping the profile of cross-sections (creating the right curve to the cross-sectional area). By inference, this invention does not minimize drag because it uses a different-from-optimal profile of cross-sectional areas. High drag = high fuel consumption and that will limit it's application to non-military aircraft.
Two wrongs don't make a right, but three lefts do.
The B-70 prototype was supposed to benefit from "compression lift" and get high lift-to-drag ratios to give it intercontinental range. The B-70 had all (six) engines clustered in a single pod underneath a delta wing, and the outer segments of the delta wing drooped down. The whole thing was supposed to get lift from the resulting shock wave bubble under the aircraft, generated by the engine pod and herded together by the down-drooped wing tips.
The word is that it didn't get the same low drag as the wind tunnel models, and the SST design that followed it didn't seem to go for clustered engines and drooped wing tips to get compression lift. On the other hand, in the high-altitude hypersonic regime you are proposing, various types of "wave riders" have been proposed.
Another concept along the lines you are suggesting came out of Lawrence-Livermore Labs (I guess they are looking for stuff to do with the end of the Cold War) where they went back to Eugen Sanger's idea of atmospheric "skip" -- you would boost something into space with a rocket and then let it skip across the upper atmosphere like a stone sent skimming across a pond. The claim for that was improved energy efficiency (over subsonic travel?), although I wonder if the reentry heating problem is worse when you have these multiple partial reentries, and I wonder how popular these skip trajectories would be with passengers apart from those passengers who want a roller coaster type ride (Vomit Comet anyone?).
Is that how they deliver all the books, then?
The great circle route from Seattle to London passes over the North Pole, and need never cross land. Why didn't Concorde ever fly that route?
I'll give you a hint. What else travels supersonically and flies over the pole?
Give up?
No commercial flights went over the pole until 2000.
A legparnasom tele van angolnaval.
No one's dropping bombs at supersonic speeds.
Damn, what a cunt. Oh well, at least it was still informative.
CAn'T CompreHend SARcaSm?
I've /used/ magnetohydrodynamics, have you? (Cambridge University Engineering Labs, 1980)
At some point, whatever magical properties the plasma has (not much) it has to move air out of the way of the vehicle+plasma field. At some point, typically directly in front of the plasma bubble the air has to move faster than it can react, so (crudely) it creates a sonic boom.
Even if there were no friction between the air and the bubble it would stll have to move out of the way.
Well, if they are 180 degrees out of phase they could be said to be in antiphase. Personally I think dictionary.com is wrong really.
For instance, if one signal is exactly 90 degrees behind another it is out of phase, but could still be perfectly synchronized, or correlated, or (technically) coherent with the first signal.
Perhaps it depends on the field of use.
IANAABIAANAVE
A=aerodynamicist,B=But, NAVE = noise and vibration engineer
I am a banana.
Can't wait. . .
Hmm, I wonder if you'd still get Peanuts and Coke budget carriers?
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The F-22 is designed to cruise supersonically without using afterburners (about Mach 1.4). There's been some talk about making an FB-22 with supercruise capability.
Mach 1.4 would be a good speed to shoot for with a new SST design - stagnation temperature at cruising altitude should be about +100F - it is possible to get nearly 100% recovery of ram air energy with multiple oblique shock waves - which suggests there may be a way of achieving an L/D not much worse than a subsonic design (wild ass guess on my part). With a, say, 5,000 nm range you could shave quite a few hours off of the longer flights - 7,000 nm would allow for non-stop Sydney to L.A. flights.
A Shadeless room is a brighter room.
You can't silence a super-sonic bullet, but you can change the sound coming from the muzzle.
... your out of luck! Bullets spin ... try archery.
As for bullet shape
That isn't what killed the TU-146. It was their inability to get modern digital fuel controls that doomed that plane. The engines were also used on a major Russian bomber and no way in hell did the West plan to help that program.
And, btw, what caused the SST crash at the Paris airshow was the TU-146 pilot having to suddenly dodge a French fighter plane that was playing hide-and-seek in the clouds trying to get some spy photos of the SST. (Why they just didn't go back and use Concorde photos escapes me.) The Russian pilot had been assured that he had clear airspace for 10 miles. Dodging the French plane broke the spine of the TU-146. The French and Russians together covered this up for a long time -- each for their own reasons.
And yes, the French copped to this finally a few years ago.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
Felt by you maybe... Boeing was also working on an SST at the time which would have meant the end of Concorde had it flown.
The laws which prevented SSTs from flying supersonic over the CONUS killed that bird costing Boeing a lot of money.
No, not even close. Try 1954. I know I've seen on TV why they stopped but I cannot find the reason now. Fear of ballistic missiles or bombers doesn't fly (pardon the pun) since telling missiles bombers and civilian airplanes apart was the main reason there even is a NORAD. It was their main operational task. Even built huge analog machines, complete with PPI:s and light pens in the fifties to cope with the burden.
Stefan Axelsson
Im surprised they let this information out, it seems exactly like the kind of top secret thing the government would want to keep secret.
While I fully appreciate the necessity of a control for an experiment, the way the article reads does not give me much faith that there was a significant difference. Maybe it is just poor wording. A shmo like me would have prefered to read "a 3 dB reduction in amplitude" or "half as loud" or something other than "Comparison of the data confirmed the modified shape of the test aircraft altered the sonic boom as expected."
One of the other non-political problems with polar flight is the fact that cosmic radiation is much stronger at the poles due to the earth's magnetic field. The FAA was worried that this might interfere with navigation and flight control systems.
retrorocket.o not found, launch anyway?
" Your logic is refuted by the fact that Concorde was in service for almost 30 years -- it carried its first passengers in 1976. The technical failures of the Russian project have no bearing on Concorde. "
No it's not. You're forgetting a major factor:
Pride. Concorde was put on government-subsidized life support because admitting that it was a failure was unacceptable to the British and French governments. Keeping Concorde alive was a matter of nationalistic pride, not of economics.
retrorocket.o not found, launch anyway?
From the article:
In flights conducted Aug. 27 on the same test range where Chuck Yeager first broke the sound barrier nearly 56 years ago...
Of course it works here. They admit themselves that the sound barrier is already broken at this location. Did anyone ever bother to FIX it in 56 years? Nooooooo. Maybe if it works at another location I will be impressed.
Dewey, you fool! Your decimal system has played right into my hands!
The people who ONLY want to go from NY to LA is a SMALL subset of the people who normally travel between those airports.
And let's not forget the hassles of check-in and such. Thanks to current security measures, even if you "just" want to go from NY to LA, you will probably get their faster if you go to Teterboro from NY and then take a private jet to Sacremento and then take a train/cab to L.A.
retrorocket.o not found, launch anyway?
get there faster, not get "their" faster.
Exactly! Stealth= life for the Air Force. Moreover, the military does not care about fuel consumption -- its only an issue of ensuring a reasonable operating range with a reasonable payload of big cans of whoopass.
Civilian applications are much more fuel economy sensitive - if the airplane is not economical, no airline will buy it. Plus, the more fuel it consumes, the more pollution it dumps into the upper atmosphere, the less likely it will ever be permitted to get off the ground. Noise is not the only reason the SST never made it into production.
Two wrongs don't make a right, but three lefts do.
The SST failure at the Paris Air show was the result of a near collision with a French fighter plane. The French were trying to covertly shadow the SST. During a tight maneuver, the Russian pilot was surprised to find himself flying into a jet he didn't know was there. He pulled up sharply, generating incredible G-forces the SST (or practically any other aircraft on earth) could not support structurally.
Quote from the article:
Comparison of the data confirmed the modified shape of the test aircraft altered the sonic boom as expected.
They're modifying the shape of the aircraft, comparing it to the old design and seeing how the data changes between runs. Saying "Wow that means it sucks" is reading too much into it, IMHO. Any experiment has a control to eliminate unexpected varaibles, in this case that could be atmospheric differences between runs (temperature and pressure, for example).
They're measuring the shape and magnitude, like the article says, with equipment so that they can demonstrate their hypothesis. They're not just listening to it and saying "Yup sounds different."
boeing and airbus have diverging opinions on the evolution of the airline industry. airbus thinks bigger is better and has spent billions to develop the A380 super-jumbo jet. boeing responded to what was then the A3XX announcement by drawing up plans for a 747X stretch derivative that would make it almost equal in terms of capacity to the A380.
building the 747X stretch would have involved adding two new fuselage sections to the existing 747-400ER. i'm not sure if this would also mean having to modify the wing design or not, which of course would have been costly (but not nearly as costly as developing the A380 from scratch). after tossing this idea to the airlines, they decided that the super-jumbo just didn't have the interest to merit two competing airliners. superjumbos would require costly modifications to airports, and outside of certain southeast asian routes, won't have enough traffic to make an investment in a 747X worthwhile. boeing brass apparently decided that the future of aircraft development would be smaller, faster aircraft that would be able to service more direct routes (rather than megahubs that the A380 would service, requiring most passengers to transfer to other aircraft to reach their destination).
this philosophy brought about the sonic cruiser. the sonic cruiser was never meant to be supersonic, so any suggestion that the FAA ban on supersonic flight over US territories killed the sonic cruiser is false. boeing tossed the idea to the airlines and decided that such a revolutionary aircraft would be too expensive to develop at this time. right now the boeing company is looking at the 7e7 program, which is a more traditional, but more efficient, aircraft, using more efficient engines, airframe, and wing design, combined with technology to reduce maintenance time and costs.
who will win? who knows... anyways, this was a long digression, but your point that the FAA ban had anythign to do with killing the sonic cruiser is wrong
If you're travelling faster than the speed of sound, no matter how loud your sonic boom is, your enemy will not hear you coming.
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Loose the type A personality. Become an under-clocker.
Sure... Turn off your CPU fan and you'll get two birds with one stone - nice silent computer, and it'll be waaaay underclocked. ;)
-T
You might get a 747 or 777 up to the mid 30K range, but not much higher than that considering fuel, passengers, and cargo. It's just not going that high. Ask any pilot of an Airbus A330. They'll jump to 39K and stay there to be out of traffic since the Boeings can't make it up there.
Plant a tree in a developing country.