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Futuristic Biplane Design Eliminates Sonic Boom
Zothecula writes "A throwback to early 20th century aviation may hold the key to eliminating the sonic boom — at least according to researchers at MIT and Stanford University. Strongly reminiscent of biplanes still in use today, the researcher's concept supersonic aircraft introduces a second wing which, it is claimed, cancels the shockwaves generated by objects near or beyond the sound barrier."
I read the article, so I know that they fixed that by taking the old design which had no lift, ran it through a ton of simulations and found a design which has the lift necessary to fix this. It's not like people never discover new things.
After reading TFA, I stand corrected. The Busemann biplane has lift, but only under supersonic flow, so they're using an adaptive wing.
Thrust is all you really need.
After reading TFA, I stand corrected. The Busemann biplane has lift, but only under supersonic flow, so they're using an adaptive wing.
Try to read again. It says the japaneese are using adaptive technology. They are just using a configuration that works both with sub-sonic and super-sonic speeds.
Actually its even older than that, according to the article:
"Wang credits German engineer Adolf Busemann for the original concept. In the 1950s, Busemann came up with a biplane design that essentially eliminates shock waves at supersonic speeds."
The real breakthrough is in minor modifications to the wing design that cut down drastically in drag, reducing necessary fuel burn. While it may not be a field-able concept yet, they are gradually breaking down the barriers to a more efficient supersonic transport design.
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The article discusses that. The news here is that the researchers think they have a modification of the design that does generate significant lift at subsonic speeds.
Even a flat piece of plywood will get lift if you angle up (from horizontal) and move it forward with the higher edge being the leading edge.
Lift is generated by air being redirected.
You can have contoured wings, flat angled wings, or wings that change attack angle or have adjustable flaps on the back that redirect the spilling air.
False. For example, when I was building a supersonic rocket, I thought of using a Busemann biplane to decrease drag drastically in the supersonic regime. However, the stabilizing function of fins on a rocket is a result of the lift they produce at nonzero angles of attack. As a result, the rocket would have no stability, and would consequently fail to launch (alternatively, I could have used gyroscopic stabilization, but putting anything in the path of the exhaust tends to be highly dangerous, so I went with a super-light rocket).
Where's the fun in that? Seriously, when I was a kid living near an air force base, I thought the sonic booms were the coolest thing ever.
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Is it me, or does that look like a Romulan War Bird? :-P
Lost at C:>. Found at C.
No shit, but the fundamental problem with the old Busemann biplane is the the lift from each wing would cancel out.
http://www.youtube.com/watch?v=70_nQpOQczM
Sonic Boom is a charge attack so maybe they are forgetting to charge.
They didn't mention the fatal crash on takeoff as one of the contributing factors grounding the Concorde, but they did say:
and there may be a boom in the field in the coming years.
Read them again. There are two planes: the MIT one has a static wing configuration. The Japanese design has a wing configuration that changes in mid flight.
Except it wouldn't.
. . . to fly in a plane that breaks the sound barrier without a sonic boom? That would be like taking the orgasm out of sex.
Pshaw. Tom Swift, Jr. solved this years ago: http://en.wikipedia.org/wiki/Tom_Swift_and_His_Sonic_Boom_Trap
Sure, sonic booms are (more than just) annoying, but that's not why we're highly unlikely to ever see supersonic commercial flight again.
The problem is that supersonic flight requires too damned much fuel for too little gain. Airlines are struggling to make a profit with today's already-fast airliners as fuel costs skyrocket. Cutting a six-hour flight (with a hour of "secure" groping before takeoff and another hour each to get to and from the airport) to a four-hour flight (with the same groping and pre- and post-travel times) just isn't that big of a deal. And it's especially not worth more than double the expense.
Figure out a way to move just as many people at a time with existing infrastructure with half the fuel, even if it means adding 50% to the travel time, and then the airline industry might get excited.
But this thing just ain't gonna take off.
Sorry.
b&
All but God can prove this sentence true.
The major thing holding back the Concord from operating domestically was the noise factor. If they could eliminate or reduce that noise level, then we could see super sonic flight from coast to coast... Probably won't happen, but one could dream....
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Why don't you guys figure this out, OOB, and get back to us.
Not very much to discuss here is it? Old blade with some text on it.
Nothing like some non-scientific anecdotal evidence to back up a flip statement.
With a zero degree angle of attack your aircraft with any amount of thrust will fall, you can achieve greater lift with a lower AoA if you apply higher thrust. It IS a balancing act between thrust, AoA and drag to avoid stalling or loss of desired speed, but thrust is the key to powered flight.
The MIT team is not using an adaptive wing. As described by Icyfire0573 above "...they fixed that by taking the old design which had no lift, ran it through a ton of simulations and found a design which has the lift necessary to fix this."
There is a team in Japan that is using an adaptive wing. Depending on exactly how the Japanese team's wing adapts, that could be an impediment to use in a commercial airliner. Thinking about current airliner designs, the wing surface shape is modified by flaps and slats, but the core load bearing structures of the wings (spars and the connection points to the airframe) remain fixed. I would be wary of a swing-wing design for commercial air, for instance, but something similar to flaps/slats would theoretically be no more of a safety risk than today's (incredibly safe) designs.
In addition to safety, there is also the simple fact that fewer moving parts would be cheaper to build and maintain.
Well, that is all well and good - but what happens at super-subsupersonic speeds?
If we can put a man on the moon, why can't we shoot people for Apollo-related non-sequiturs?
WW1 biplanes didn't have a sonic boom.
Yes they do, if you get anywhere near the speed of sound, there is a distinctive 'boom' of it hitting the ground.
E and F engine rocket kits are supersonic. Not much more then an Estes.
I'm pretty sure some of the 3 stage Estes rockets can go supersonic on 2 Ds and a C. They lose their fins when they do though. I never did find anything but one of the fins.
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The Busemann biplane came up when we did supersonic aero in University back in '98 or '99 and it was always stated to be an impractical wing design because, at the supersonic zero boom/zero wave drag condition, it couldn't produce lift; this doesn't stop it being useful for other things like shells etc. where you don't mind zero supersonic lift if you can get low drag
The diagrams in the article seem to look like that condition in supersonic flow where the "inner" surfaces interfere favourably with each other to cancel wave drag and have the upper and lower surfaces with no incidence to the flow so they produce no shock waves.
Supersonically it should still produce lift quite happily if you angle it so there is incidence to the flow but I think that it should then produce wave drag and booms... For example I can't see from the article how, in a lifting condition, the shock wave from the compression of the supersonic flow on the undersurface (which produces the compression & higher pressure that helps lift the wing) could be cancelled out without having another wing underneath that; then you have the same problem with the undersurface of that wing & then you're in a "it's wings all the way down" problem.
Conventional 'low boom' solutions (like the Gulfstream/NASA "quiet spike") all tend to shape the nose of the aircraft to reduce the suddenness of the pressure increase across the shock wave but they aren't able to eliminate it...
It could be that they've found a case where they can get low wave drag/boom while still producing some lift and also getting decent subsonic lift/drag - that would be really interesting...
How is the pilot supposed to see the runway in that? One of the problems with the Concorde was that the pilot couldn't see the runway, which they addressed by causing the nose-cone to pivot downward during take-off and landing (which caused its own problems). This design looks even worse from that perspective.
I have new socks on.
What's wrong with a swing-wing? The USAF has used them since at least the 1960s and still uses swing-wing aircraft today. The B-1 even is similar in size to an airliner: Rockwell B-1, Boeing 737 (smaller) and Boeing 747 (bigger). It would seem to me that if a similar sized aircraft, travelling faster, at comparable weights, is sufficiently strong for military use, it should be plenty strong for commercial air travel. I imagine that it would be quite a bit more expensive to maintain than a fixed-wing airliner, however.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
It is kinda cool that they found a way to eliminate the sonic boom, however the concept is ugly. Plus, I don't think there is much interest in super sonic aircraft as they tend to be very thirsty and oil is not inexpensive.
With a zero degree angle of attack your aircraft with any amount of thrust will fall...
Are you sure about that? I think you confused "angle of attack" with "coefficient of lift."
There are airfoil designs (basically, any asymmetric airfoil) that will produce lift at an AoA of zero degrees. If lift is non-zero, then the only question is how fast does an aircraft need to be going to generate enough lift to overcome weight at a zero-degree angle of attack?
Also, just to be pedantic, the balancing act is between lift, weight, thrust and drag. Lift is related to AoA so I'll concede that you basically covered that force, but you completely neglected to mention drag above.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
Looks to me like it might be a good profile for a ramjet. If so you could have your whole wingspan produce thrust. Am I wrong?
Only if by "near the speed of sound", you really mean "a little over 100 mph."
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
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you need to finish reading the whole thing. The stanford/MIT version is what is being talked about. The japenese version simply was a reconfirmation of work done earlier that backed the dual wing. Nothing more. The stanford/MIT modification gave it lift via static configuration, while the japanese version would have to change wing shape dynamically ( read expensive).
I prefer the "u" in honour as it seems to be missing these days.
The B-1 is from carter's time. IOW, it is an OLD bomber. Not as old as B-52, but old in design nevertheless.
I prefer the "u" in honour as it seems to be missing these days.
Cost, weight and lost cargo/fuel space. The three demons of commercial flight.
Sure, but it's still in service today, which is all I said above.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
I would be wary of a swing-wing design for commercial air, for instance, but something similar to flaps/slats would theoretically be no more of a safety risk than today's (incredibly safe) designs.[emphasis mine]
My point is that if an F-111 or B-1B can survive combat, they certainly can survive commercial service.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
... and proceeds to defeat Guile, only to fall prey to an electrical storm in Brazil. Blanka continues on to defeat Balrog and a helicopter, but gets taken out by Vega's cheap wall leaps.
This is not a breakthrough, it is just a canard.
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If you magnify the pilots window and apply the CSI software to it, there's a beagle flying that aircraft!
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The engines are of a much older design. They still burn kerosene, or whale oil, whatever it is. We are very 19th Century in terms of propulsion. Though I will grant reliability is way up.
they didn't eliminate flash kick
Of course that's the speed of sound. It's the speed at which the wind resistance makes sound.
I hear it's a big wooshing noise...
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Lock X Foils in attack position...!
I'm pretty sure some of the 3 stage Estes rockets can go supersonic on 2 Ds and a C. They lose their fins when they do though. I never did find anything but one of the fins.
I got bored with model rocketry after my first three rockets were one-shot flights, never to be found again. I wonder if this explains why. How soon do they go supersonic? I was able to at least see that mine went straight up until my eye couldn't resolve them anymore. If they went supersonic, they'd start to tumble, right?
I never saw a parachute, but didn't hear any explosions either.
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It's not a canard at all, completely different principles. A canard is designed so that the forward wing will always stall before the main wing, ensuring that the entire aircraft has significant positive stability. Combined with the benefits of a pusher propolsution, you get a stable yet maneuverable aircraft.
Designing a bi-plane to reduce the sonic boom is resolving a completely different problem, using completely different designs.
Estes rockets were fun, I remember when I lost a fin on one of mine, it hit a boat behind a house, I really thought it was going fly right into the house. I do agree, I never tried it but a friend of mine would use a couple of Ds, and always lose the rocket.
It is kind of... weird that we can't seem to scale up the speed of fighter jets and the like. But we'll solve it soon enough. The Concorde was an interesting experiment, but this might actually be usable.
I just hope the layperson would be able to use it in 20 years and that the airports still won't be a wasteful black hole of time-seeping despair. A 5 hour security checkpoint kinda deflates the fun and novelty of popping over to Britain for dinner with a friend and then back home to sleep.
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Sure. But so is the B-52 as well as KC-135 (military version of B-707). Think that those are good models to follow?
I prefer the "u" in honour as it seems to be missing these days.
I wonder if there's any way to make a projectile with similar characteristics?
by Mike Buddha -- Someday the mountain might get him, but the law never will.
Yes, and we even use Newton's Laws of action and reaction from the 17th century! How old is THAT!? We should try to find new physics or something. Idiot.
I wonder what happens if the cancellation effect gets out of sync. Maybe a wing loses a bit of material or hits an air pocket that the other wing doesn't experience.
In my head I see this plane zooming along supersonic, hitting some turbulence, shaking a bit, then BOOM! the whole thing explodes into bits of carbon-fiber and aluminum confetti.
Try some lateral thinking.
Never answer an anonymous letter. - Yogi Berra
Now I might well be wrong here, but doesn't the leading edge of the aysmmetric airfoil have to be higher than the trailing edge to create lift once power is applied? In other words, wing incidence is required? If this design is symmetrical and there is no incidence, I think it can only create lift if they point it up under sufficient power. Any aeronautical engineers in the house?
The military isn't investigating new swing wing designs, even though they have obvious benefits for carrier launch planes and supersonic planes, simply because they cost too much to keep in the air. It's unlikely you'll ever see a commercial one for the same reason. It's too expensive to have moving portions of the wing supporting the weight of the aircraft.
Okay, the first half of your post was funny...but is this reading-comprehension-fail-day on /.? No, there was no whooshing noise over my head. I understood the joke that the "sonic boom" was the sound of the airplane crashing ("Boom!" ha ha). My point was that WWI biplanes don't approach anything even vaguely resembling the speed of sound. WWI biplanes come apart in the air at speeds that I have achieved in the low-end Cessnas* in which I learned to fly -- which is a far, far cry from the speed of sound.
*Granted, not in level flight, and I was approaching red-line speed, but flying short-final at near Vne was a lot better than getting run over by the 747 that was breathing down my neck.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
have the second wing able to come out or slide out as you near the speed of sound and once past you keep it as the article says it works great above supersonic but not before.
Yeah... it was weak. I'm sorry, I was in the middle of battling three deadlines. (Two of them are now winning.) It seemed like a witty thing to throw in there at the time. The true Tao of Slashdot, though, is that you can always make a "Woosh!" comment, and claim there is some inner secret in the previous statement that no one else will ever understand. Sort of like a socially inept version of no soap radio.
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LOL. Good luck with the deadlines!
By the way...sorry to be grouchy earlier
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
pfft this will just make it even easier to beat Guile now!
You are thinking of scramjets. The flow is supersonic here.
Something bad is coming when people are suddenly anxious to tell the truth.
Now Guile will probably lose all his fights :(
Now I might well be wrong here, but doesn't the leading edge of the aysmmetric airfoil have to be higher than the trailing edge to create lift once power is applied?
Nope, camber can be used to generate lift.
Stop! Dremel time!
No, since we still know virtually nothing, we should make a more than feeble attempt to understand the the 'old' physics. Fool.
You missed out. I recall one rocket that I got over 50 flights on. Then we discovered the reloading department at the local gun shop (truth is, Dad clued me in when he caught me getting ready to cook some nitroglycerin.)
I only ever launched one 3 stage D engine rocket. Never saw the top stage light. Only found a fin. Barely found the second stage.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
.I only ever launched one 3 stage D engine rocket. Never saw the top stage light. Only found a fin. Barely found the second stage.
Oh, I forgot to write that this was my problem. They all had multiple D engines in them. If I had stuck with the smaller ones (or perhaps lived on the Great Plains) it would have been much more rewarding!
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Interesting concept, but there is no working model and the sub-supersonic speeds could be a significant issue. I was imagining an electromagnetic run way that thrust the object up to speed and the entire flight is made at super-sonic speed. Landing would be another issue.
Anyhow, it seems kind of like a computer model dream until they get some working models
I agree that all of those are valid reasons for manufacturers not to build a swing-wing airliner. However, and perhaps I was reading to much into the post, it sounded to me like Chuckstar didn't trust a swing-wing design, not that he thought it would be too costly and inefficient to use in commercial air service:
I would be wary of a swing-wing design for commercial air, for instance, but something similar to flaps/slats would theoretically be no more of a safety risk than today's (incredibly safe) designs.[emphasis -- and additional emphasis -- mine]
My point is that if an F-111 or B-1B can survive combat, they certainly can survive commercial service.
I did not say that it was economical, efficient, or even a good idea to build a swing-wing airliner. I said that concerns about structural integrity was not a reason to avoid swing-wing aircraft.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?