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Towards Silent Supersonic Planes
Roland Piquepaille writes "There is no longer a single commercial supersonic airplane since the retirement of the Concorde last year. And even during its years of glory, the Concorde was not a commercial success, mainly because it was not allowed to cruise at supersonic speed over land. Why? Because of the sonic 'boom' which arises when you break the sound barrier. Now, a joint program between NASA, the military and the aerospace industry wants to remove, or at least reduce, this sonic boom, by changing the shape of supersonic planes. It seems to work. After a 'nose job' on a Northrop Grumman F-5E, about a third of the pressure released when breaking the sound barrier has already been suppressed. This overview contains more details. It also includes a photograph of the modified Northrop Grumman F-5Ea aircraft flying off the wing of the F-15B research testbed aircraft. [Note: Previous results were reported here by Slashdot in last September.]"
If we could only do something about my neighbour's pounding stereo.
The dangers of knowledge trigger emotional distress in human beings.
The concorde was EXTREMELY expensive to operate, so even if it was allowed to travel supersonic anywhere it wanted, it still would have failed. airlines are cutting every cost possible in an effort to undercut each other, so the concorde's death was just waiting to happen.
Common, you can't tell me the first thing you didn't think of when reading this story was Street Fighter 2.
Would it be possible to direct the sound of the "boom" upward so that nobody on the surface hears it?
How am I supposed to fit a pithy, relevant quote into 120 characters?
They've only been promising a solution to the Sonic Boom problem for, what, 30 years now?
Not only did the Concorde jump the gun by a few decades, I think it's hindered any development into the field of Commercial Supersonic Transport by being an noisy fuel-hog... Though it was one of the most beautiful planes ever built, right up there with the SR-71...
"If we let things terrify us, life will not be worth living."
- Seneca
Oh, com'on, the Sonic Boom was one of Guile's best moves.
But seriously, while this could be very cool for frequent travelers, I still think that even regular airplanes are too loud. Especially if you live relatively near an airport. Are any airplane manufacturers working on quieter sub-sonic planes?
[SIG] It's like putting a moose in the blender -- a recipe for disaster!
There was a smaller article like this in Popular Science a while back, and since I am very interested in planes and aerospace, it now is on my wall. I'll type it down for you guys, I'ts actually very interesting...
All Zoom, No Boom
Teaching an F-5E Tiger how to tiptoes.
There's nothing more dramatic than a supersonic jet streaking overhead; and nothing more annoying than the bone-rattling sonic boom it leaves behind. The boom really consists of two bangs caused by the N-wave in the planes wake, with rapid pressure rises corresponding to the nose and tail. Northrop-Grumman hopes that by tailoring a F-5E Tiger with a longer nose an modified tail, and tinkering wiht its body and wngs, the boom can be transformed into a smooth, inaudible hump. Engineers got the idea from research that goes back to the 1970's. Today's computers, which make it possible to model airflows up to 200 yards from a plane, were required to put the theories into practice. Tests being next august. --Written by Bill Sweetman.
I don't know exactly when it was published, but it shows that this is really no new idea. On an interesting side-note, my uncle worked for McDonald Douglas before they were bought out by Boeing, and actually was a systems engineer for the Coherent Readar systems for the F-5F. When I told him about this he thought it was one of the coolest things he'd ever heard.
~I was playing poker with tarot cards the other night. I got a full house and that same night five people died. True story.
People care more about the cost and security of air travel. It was never about the sound (although that didn't help), it's just down to the cost of fuel and limited range of the craft.
Where anyone on the ground would wear networked noise cancelling headphones.
Sure, the sonic boom wasn't too good, but that never stopped the US Air Force from flying their supersonic planes day in and day out over populated areas. I still remember periodic sonic booms over Tucson (from a nearby base) as well as over Seattle whenever Boeing was testing their latest SS jet fighter.
Let's face it, the main reason the Concorde wasn't allowed to fly over the US is because it wasn't US made.
Most supersonic aircraft require afterburners in order to go faster then sound, and afterburners are incredibly voracious consumers of fuel. I think that one of the other very important innovations is the "Supercruise" ability, seen on aircraft like the F-22 Raptor. This allows the aircraft to maintain supersonic speed for extended periods of time in a low power setting, and this in turn is just as vital for cheap, commercially viable flights. I hope that advances in sonic boom suppression will also work well with the necessary designs for supercruising, and that we may all be able to take advantage of such flights within the next 2-3 decades. If both aren't taken into account, and designers come up with plans that make for an either-or choice, it could mean supersonic planes will still be relegated to the relatively wealthy.
Geeks like us, and researchers looking to get more grant money, have been babbling about fusion, flying cars, a return to the moon, a trip to Mars, terraforming Mars, anti-gravity devices, transporters, replicators, eternal life, brain transplantation and human cloning for-fucking-ever. YOU KNOW WHAT? I AM FUCKING SICK OF READING ABOUT SPECULATIVE FLIMFLAM. I want to read, for once, a story like:
Flying cars being sold from reputable Web site for $20,000 RIGHT NOW
Holy shit: Man lands on Mars!
Fusion reactor perfected; lauded as "great success". Test reactor already tethered to power grid generating $BIGNUM megawatts; construction on fullscale reactor underway. AND...
Silent supersonic airliner makes first of new daily Transatlantic flights wearing $MAJOR_AIRLINE colours. Book tickets at $URL.
Stop wasting my fucking time until something is actually AVAILABLE NOW. God, I'm fucking sick of reading this kind of pie-in-the-sky bullshit! It's all over SlashDot and, to a lesser extent, all over the "mainstream" news media. Fuck this shit, I don't want to hear about how "at some point in the "near" future" we "may" have such-and-such. I want a fucking link to buy one on walmart.com.
Fucking Christ, are all research organisations just like us geeks-- starting projects but never finishing them?
Oh, and you over there at moller.com: STOP BABBLING ABOUT YOUR GOD-DAMNED FLYING CARS AND START SELLING THE FUCKING THINGS ALREADY!!! YOU'RE ALREADY 10 YEARS LATE, YOU FUCKWITS! And if the FAA won't let you sell them in the US, SELL THEM ELSEWHERE. RIGHT FUCKING NOW!
Honey, I shrunk the Cygwin
This is an interesting project that could improve the future of supersonic travel, but what is really needed (as with almost any technology just coming to the general market) is to bring the price down. There is certainly a market to speed up oversease flights (such as California to Japan) and a cheaper supersonic plane could really do a good business.
_____
Thank you.
To go off on someone for getting an airplane wrong.. and getting the airplane wrong yourself.
The plane in the top right is definitely an F-15 as is stated in the caption. The side-mounted air intakes are a little hard to see, but are obviously different from the bottom-mounted air intake of the F-16, however the giveaway is the tail. F-16s have a very differently shaped tail than the F-15, and it's an F-15 tail in the picture.
Takes 2 hours to get through the bloody airport and into the plane anyway.
Besides, whats the best we can do commercially? Mach 2 or 3 in the 'near' term (15-30 years). Big deal. Given the cost/benifit ratio I'm going to wager that we will be doing sub-orbital before we have air-breathing mach-3 flight.
Why? The amount of development required to develop 'quiet' and 'fuel efficient' supersonic craft vs. the level of technology already in existance for boosted flight. Leave the atmosphere and sound isn't an issue, and saves a lot of fuel as well; although spending an hour weightless is bound to upset a few tummies.
Either way, I am desperate to see some faster travel. 8 hours to Chicago from London 57 years after breaking the sound barrier and 35 years after landing on the moon is a sad commentary on the human condition at present.
That plane is used for training purposes to be the agressor, it looks like one of the Navy OpFor planes from Palomar. The us military uses mocked up soviet equipment, or sometimes even real soviet equipment to train against.
I used to have a cool sig, back when I cared
The bottom left photo is not a F-20. There were just 1 or 2 made, and they are owned by Northrop, not the Navy.
The F-5 in the lower left is owned by the Navy. The reason that it has the Red Star painted on it is that it's an agressor plane used by the Top Gun dogfighting school.
If tits were wings it'd be flying around.
...and a matter of peronal taste, but I think the XB-70A Valkyrie was sweeter than either Concorde or the SR-71.
Most people find that the pressure is a lot less after they get a nosejob....
The reason the Concorde was an economic failure was not the sonic boom - it was a failure because of the enormous fuel consumption per passenger, as well as the enormous maintenance costs per passenger. This was true even though the airlines purchased the Concordes for $1 apiece, and there was no purchase cost to amortize.
... they were trying to drum up support from some newsies for a news short on TV, sort of free advertising. Playing the odds figuring so many reporters/broadcasters whatever were there, some one might have took an interest in it. My guess anyway, or someone back at SST headquarters sent them to the wrong show! Might have happened....
Of course, ya never know. I worked tradeshows for 15 years, I have seen some thoroughly weird stuff, and some incredible stuff that just disappeared, never heard of it again. One I remember though, it had to be that dean whassis his name with the segway, his earlier invention, the super wheelchair thing that could climb stairs, and was either voice activated or breath pulses activate, along with a normal joystick. Slickest thing ever, had a tiny cheap 10 foot backwall booth, just pipe and drape and a table, on a medical show, about the cheapest booth there and definetly the best tech on the show that I saw. Another time on a car show, lamborghini had a booth, this was before the explosion in giant SUVs, they had this incredible 4 wheel drive vehicle, with the v-12 engine in it that was in the countache, etc. Dang car was NICE, I mean, r-e-a-l nice, most plush and most rugged thing I ever saw for a passenger vehicle. Cheap old 20 foot of carpet, no booth, just the best vehicle in the show and a little sign on an easel said lamborghinni, that's it, they didn't need no blinken lights booth.
and don't get me going on booth babes.....
Except that the whole drawback to PDEs is... wait for it... THEY'RE TOO BLOODY NOISY!
The concorde was a major money maker for BA, less so for Air France. The fuel costs were expensive but not unprofitably so. A standard 747 holds 300 people, most in cattle class. All seats on Concorde are first class.
The reason the plane failed economically was part due to the oil price shock hitting when Concorde entered service. A much bigger factor was Boeing lobbying to have Concorde banned from the main US airports, a piece of protectionism the US govt. went along with.
The Concorde consoirtium had the last laugh, these days it is known as Airbus and the Economist thinks it likely that Boeing will be out of the civil aviation business entirely in ten years time. In response to the US protectionism the EU underwrote development of Airbus. Boeing tried to respond with the idiotic 'fly by wire is dangerous FUD' and the rest is la historie. Boeing's current survival strategy is renting some very overpriced fuel tankers to the pentagon that meet far fewer of the original criteria set than the Airbus bid and cost about twice as much. But don't call that protectionism, its free enterprise.
Looking for an Information Security student project suggestion?
Try http://dotcrimeManifesto.com/
It's created constantly by supersonic flight. It's a byproduct of the air pressure in front of the plane being extremely high, steadily decreasing as you head back to the tail, and a sharp rise behind the tail when the pressure snaps back to normal.
This is why there are two booms from each aircraft. The first one from the pressure wave preceding the plane, and the second from the posterior wave.
"If we let things terrify us, life will not be worth living."
- Seneca
"the Economist thinks it likely that Boeing will be out of the civil aviation business entirely in ten years time" Well, certinally they will, because we all know that they aren't selling any planes right now, and it'd be impossible for them to develop any new planes out of composite materials with quieter engines. Oh yeah, there's no way things coule possibly turn around for them.
Riiiight...
Top right - F-15
Center - Modified F-5
Bottom left - Standard F-5, painted in TigerShark livery.
The F-20 is just slightly different frm the F-5, as evidenced by the extra bulk around the tail root.
This particular F-15B from NASA has a different nose. More pointed than a line model. That is why you were confused.
Would you like fries with that?
During the SR-71 development, Lockheed agreed to reimburse the cost of repairing windows broken due to the aircraft's sonic booms. To help people prepare for the sonic booms, they'd announce supersonic test flights ahead of time in the local paper. Once, they announced a flight but never actually made it. The complaints still streamed in though, from people wanting free windows replacements.
...Are cruise planes.
:)
/. reader with more physics knowledge tell me if this can/ cannot work?
There are lots of people that want to do New York- Paris in 1 hour, but most people I know aren't in that situation.
Maybe a blimp-like plane, that could transport transatlantic freight faster than a sea ship but at similar cost, or passengers on a leisurely voyage.
Fuel savings could make up for some of the extra costs. Better efficiency might appeal to the green crowd too.
Other advantages would include less jet-lag, and hopefully a more relaxing adventure.
And another one: terrorists aren't likely to send a blimp into a building at a stealthy 100kmh
Ok, can some
Information: "I want to be anthropomorphized"
Air Force uses an F5 variant called the T-38. You see the Shuttle pilots flying these around, and they are used as the chase planes on landing.
Good aircraft. They are supersonic, nimble, stable, and are good for teaching multi-engine techniques.
I have something in common with Stephen Hawking...
Some of us don't care whether reported technology is immediately practical. We visit .\ for entertainment; for us "nerds," that often means science news that's cool or interesting, regardless of the technology's maturity. We don't visit .\ to learn about how to improve our lives, though sometimes we do learn such things. We visit it for fun.
A lot of intriguing stories are for our own mental enrichment; an external reward is not necessary. They're not time wasters (in the fundamental sense) for us when they grant to us what we desire.
If you only want to read about the big events that affect standards of living, I suggest CNN.
The Concorde operation was profitable once they were purchased for a pound, or whatever it was. The fuel capacity of concorde was 96 tonnes and it carried around 100 passenger, each of whom paid about $10000 for return trip.
Fuel costs about $400 per tonne plus taxes.
You do the maths.
The sonic boom is constant. It is because the sound source is travelling than the sound itself, thus the wave doesn't have a chance to decay before it is regenerated by the travelling object. The individual waves add up to form the sonic boom.
When a jet flies by, you would hear two booms: one at the front when the nose pierces the air, and another at the rear when the air fills the void behind the aircraft (in theory its polarity would be opposite that of the first).
Read about it here: Doppler Shift
-Billco, Fnarg.com
And in the larger sense, what is the fuel efficiency delta between the quietest plane verses the most fuel efficient design possible.
Unless that delta is quite small, I'd say it ain't going to happen.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
[Note: If someone can identify the third plane on the lower left corner of the picture, please tell me what it is.]
I could tell you, but then I'd have to kill you.
The reason it *failed* was because one leveled an apartment building when it crashed, and the other's seemed to have the same problems it had, maintenance/design-wise.
You may not realize this, but there are people, lots of people, who are both willing and able to pay $10,000 for a plane ticket, if only to get from London to New York in half the time. For some people (bankers, investors, musicians, models, movie stars, people of that nature), it actually makes damn good financial sense to pay that much extra for a ticket. When you make $10,000 for a 2 hour appearance, you can fit in 2 extra appearnces with that much time earning yourself an extra $10k.
Just because most people in the world can't buy a house that sells for $41 million dollars doesn't make it a failure in the real estate business. Someone out there can and will. It becomes a failure when one or two of the rooms cave in on the new owners, and no one wants to buy it from them.
No trespassing. Violators will be shot. Survivors will be shot again.
The 'boom' is a continuous shockwave that occurs as long as the vehicle is at supersonic velocities. This is why these planes have generally not been allowed to fly at supersonic speeds over occupied land.
Basically there would be a violent rumble on the ground over the entire length of the plane's flight corridor. The idea is to reduce or remove entirely the shockwave coming off the vehicle surfaces.
-
That third plane is also an F-5 Tiger. Look at the fairing between the tail fin and the fuselage as well as the cockpit design, both are exactly the same. You'll notice that the sonic boom is only changed below the plane, the top is not changed at all sinec nobody really cares about the boom above the plane.
While I agree that Boeing did some bad things during the 1990s I can't help but notice that they did build the 777 wide body during that time and that airliner has sold very well and has had a good amount of backlog at their factory. It completed very well against Airbus' widebody twinjet the A330 and to some extent to A340. If Boeing hadn't built the 777 then Airbus would have gotten alot more widebody twinjet orders than they did.
The main boom is the one I was describing, and as far as I can tell, it was accurate. At least the Wikipedia seems to agree with me:
"If we let things terrify us, life will not be worth living."
- Seneca
The really interesting news along these lines is that Lockheed's Skunkworks is working on supersonic business jet. Its rumored that Warren Buffet is behind it.
For those that don't know, Bershire Hathaway owns Netjets, the largest purchaser of business jets.
If Boeing's 7E7 project turns out to be substantially less successful that Airbus's 380 project, Boeing might not have the capital or the time to design a new cvil aviation platform--preferring instead to suck on the Pentagon's teat.
Airbus thinks that the airlines will continue to consolidate their hubs. If so, they'll ditch the aging 747 platform for A380.
Boeing thinks that airlines will add more nonstop routes between secondary cities-- e.g Detroit to Shanghai. If so, they'll probably buy more 7E7's, as unlike the older Boeing planes, the Dreamliner is substantially more fuel efficient that the Airbus offerings.
1. The plane's Olympus 593 engines were serious fuel guzzlers and made a tremendous amount of noise on takeoff, especially with the afterburner (known as reheat in Europe) running. Also, they definitely don't meet today's standards for jet engine exhaust emissions, either.
2. The plane's range limited itself to flying between New York City and London/Paris--and even then the plane require priority handling by air traffic control during its flight.
3. The plane's carrying capacity was too low for its size.
4. The plane--because it had to fly at Mach 2-plus--needed very careful design for heat-dissipation reasons.
I think for tomorrow's SST's, the technologies now available will do the following:
1. By carefully shaping the entire plane, this drastically reduces the pressure wave buildup that causes the sonic boom in the first place. By limiting the top speed to around Mach 1.7 when the plane flies at altitude the sonic boom may be barely audiable or not audiable at all.
2. The use of modern aerospace materials means the plane can be quite a bit lighter, which means you can consider larger passenger and/or cargo loads. Also, because the plane is limited to Mach 1.7 top speed there is less pressing need for heat-resistant external surfaces.
3. Jet engine technology improvements since the 1960's will allow for SST jet engines that are very quiet on takeoff and landing (meeting even the upcoming ICAO Stage IV noise standards), yet operate efficiently at supersonic cruise. Also, improved combustor designs will drastically reduce the exhaust emissions that plagued the Olympus 593 engine. Because the top speed is only Mach 1.7, it may be possible to apply the supercruise jet engine technology used on the F-22 Raptor's jet engines, which means less need for afterburner (reheat) operation and lower fuel burn.
In short, we are very close to developing a Mach 1.7 SST seating 200-250 passengers that could fly over 6,300 nautical miles, be very quiet on takeoff and landing, not be an environmental hazard from jet exhaust and have sonic boom that is almost non-existent. Imagine being able to fly from San Francisco to London at Mach 1.7--we may be talking about cutting nearly 40% the flight time compared to a Boeing 747! =)
The speed of sound at 30,000 ft above sea level is about 678 MPH
So at top speed thats: 89% the speed of sound (damn near 90%)
And At cruising speed it's: 83%
Pretty Close.
The article refers to Concorde as the only supersonic passenger aircraft. That is not the case; the russian Tupolev TU-144 ran a short lived passenger service in the late '70s.
:)
Of course it was even less efficient than the Concorde, but it did exist
http://www.themeparks.ie
The joke among BA folks was that the only way they would ever get the FAA to approve supersonic flights over US territory was to paint "Boeing" on the side of the Concorde.
The aircraft looks to be a non-modified F-5E.
Paint scheme make it look like a Soviet Aircraft, making the aircraft most likely to come from the Nellis Airforce Base where the Red Flag exercises are done.
A standard 747 holds 300 people...
Not so. A standard 747-400 (most recent model) holds 416 people in a three-class configuration. Charter 747s with all-economy seating can hold 500 or more.
All seats on Concorde are first class.
No, they were Concorde class; a step above first class.
Aviation fuel is not taxed, much to the disadvantage of the environment. If it was taxed at the same rate as automotive fuel is in most of the world, flying would be priced where it should be, i.e. out of reach of most people, and there would be substantial environmental benefit.
Because there are much less airplanes than there are cars. If plane emissions ever start to get anywhere even NEAR that of cars, you can bet that they start to get taxed more.
Jet aircraft have done far more damage to the ozone layer than anything else.
Links, please. Planes emit mostly CO2 and Nitrogen oxides just like anything else that burns fossil fuels, NO's do destroy ozone, but nowhere as efficiently as chlorine, and only supersonics fly high enough for their emissions to make it into ozone layer. Now that concorde is gone, only supersonics are military aircraft, not much hope trying to prevent those from flying with taxes.
On lower altutides that most jet aircraft fly at, NO's actually stimulate ozone production, of course on the low altitudes it's a pollutant of it's own and a greenhouse gas as well.
I had a chance to visit the British Airways Concorde at the Museum of Flight at Boeing Field in Seattle, WA and I don't know if I'd call those seats first class other than there are only two seats on each side of the plane. To protect the seats they've covered each side of the interior over with curved pieces of plexi-glass and the remaing isle is very narrow. In looking at the seat size it looks smaller than a first class or even business class seat on a widebody jet but since I could only look at the seats and not try them out I can't do a real comparison. I guess it would be tolerable though given the much short travel time in flying on the Concorde.
The other thing that struck me about the Concorde was how small the interior is and the door is quite low going into the plane. I had to duck as I entered the plane to keep from hitting my head on the doorway.
I don't have much knowledge of aircraft certification, but I do have some knowlege of certification processes in other industries.
The difference is in where the burden lies. Apparently (taking the parent post at face value), in the past manufacturers had to prove to the FAA's satisfaction that a design was safe. Now, they just have to give the design to the FAA, and the assumption is that it will be certified unless the FAA proves that it is unsafe (therefore the burden of proof is on the government).
Obviously this is a lower standard - since those most able to find flaws in the design are the designers, who work for the manufacturer who wants their design approved.
Honestly, I cannot vouch for how the FAA certification process really works, but in most industries that are regulated the burden of proof is on the industry - to prove that they are operating within the regs. The regulatory agency merely audits their processes and looks for signs of things being out of order. Industry is supposed to police itself, while the govt polices the police. This has the benefit of shifting the safety costs to the industry - where they are ultimately reflected in the prices of goods (which makes sense - if planes cost a fortune to make safe it should be reflected in the cost of plane tickets, so that consumers can take a train if it makes more sense).
I'm always open to alternative systems if they actually work...