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Transportation Technology

Futuristic Biplane Design Eliminates Sonic Boom 140

Posted by Soulskill
from the suborning-supersonic-silence dept.
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."
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Futuristic Biplane Design Eliminates Sonic Boom

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  • No sonic boom? (Score:5, Insightful)

    by 93 Escort Wagon (326346) on Monday March 19, 2012 @02:27PM (#39406387)

    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.

    • They're really not supposed to do it according to the rules, but yeah, I had the same thing growing up. Every so often the whole house would shake, and we didn't even live all that close to an airforce base (just in the middle of nowhere so I imagine they liked to do training there). I imagine some people got dressed down pretty thoroughly whenever it happened. But the only thing cooler was the mock dogfights (only ever saw those twice the whole time I was growing up though).

      • i grew up on air force bases. i could be wrong, but as frequently as the sonic booms occurred, i'd bet nobody got dressed down for that. if they gave a shit about sound pollution, they wouldn't put housing next to tarmacs where they keep their C-5s. i can't count how many times i feel asleep (or woke up) to their engines.
        • by sjames (1099)

          They don't care about the noise pollution, they care about the broken windows and things rattled off of shelves.

          • i don't think they care about that either. the planes would have to fly pretty low to the ground while breaking the sound barrier to break glass or shake things off shelves. it does happen, but not that frequently if you're one who lives around these planes. living around air force bases, you'd be used to the sounds of sonic booms, but most of them occur too high up to do any physical damage. it just sounds like thunderclaps all day without the storm.

            but we do agree, they don't care about noise pollution
      • by Anonymous Coward

        As a general rune, Air Force and Navy regs prohibit supersonic flight over land outside designated airspace. Of course if you are living near an Air Force or Navy fighter base, it is likely that there is a nearby chunk of Special Use Airspace that is approved for supersonic flight. If you lived "in the middle of nowhere" it is likely that you were living under SUA and supersonic flight was approved, usually above 10,000'.

    • by X0563511 (793323)

      From my limited understanding of things, that shock front on the leading edges causes a rather large amount of heat to be dealt with. I'd imagine getting rid of that lets you save cost/weight/designer-hairpulling when working with the principle.

      Eg, I seem to recall the SR-71's leading edges were actually designed to handle deforming at said high-temperatures. You have to admit that getting rid of that complexity would be a good thing.

      • by Baloroth (2370816)

        And of course the shock-wave itself causes some major control issues as you pass through the barrier itself, at least as I understand it, as well as creating a huge amount of drag. That is a large reason they had so much trouble breaking the barrier in the first place: the planes would lose control as they passed through it and crash. How much eliminating the "boom" itself will help with these problems, I don't know.

        • Re:No sonic boom? (Score:5, Interesting)

          by element-o.p. (939033) on Monday March 19, 2012 @03:41PM (#39407125) Homepage

          And of course the shock-wave itself causes some major control issues as you pass through the barrier itself, at least as I understand it, as well as creating a huge amount of drag. That is a large reason they had so much trouble breaking the barrier in the first place: the planes would lose control as they passed through it and crash.

          Yep. There were two big problems with control. The first was that as you move from subsonic to supersonic, the center of lift would move. The aircraft was balanced for controllability at subsonic flows, but when you passed from subsonic to supersonic, the aircraft became unstable and would either crash or break up. The second problem was that the control systems were easily manipulated by the pilot at subsonic speeds, but the shock wave created at the control surface hinge was too great for a human to overcome -- pilots literally weren't strong enough to push the control surfaces against the shock wave until engineers developed all-flying tail surfaces (stabilators rather than elevators). Overcoming drag was basically just a problem of developing a powerful enough engine.

      • by Arrepiadd (688829)

        I seem to recall the SR-71's leading edges were actually designed to handle deforming at said high-temperatures.

        It was not only the leading edges that were designed that way, the entire plane was designed taking into account that it would expand. Here's an interesting citation from the Wikipedia page for the SR-71 [wikipedia.org]:
        "To allow for thermal expansion at the high operational temperatures, the fuselage panels were manufactured to fit only loosely on the ground. Proper alignment was only achieved when the airframe heated due to air resistance at high speeds, causing the airframe to expand several inches. Because of this, an

    • by Anonymous Coward

      Only the air force is allowed to make those sonic booms over land. A no sonic boom aircraft would make it possible for a commercial airliner to fly supersonically overland. The Concord was only allowed to fly supersonically over the ocean, limiting it's usefulness. A silent supersonic airplane with a high enough fuel efficiency would mean intercontinental flights in much shorter time. NY to LA would take 0h (after time zones) and LA to NY would take 6h instead of 9.

    • Re:No sonic boom? (Score:5, Informative)

      by jamstar7 (694492) on Monday March 19, 2012 @03:03PM (#39406773)
      One of the problems with the Concorde was, they weren't allowed to fly at supersonic speeds across the US because of the booms. So, supersonic London to LA was flat out of the question. From what I understand, a lot of other countries followed suit, outlawing supersonic flights in their airspaces. Without the speed advantage, the Concorde was a low passenger fuel hog that turned into a hanger queen and eventually got grounded and decommissioned. Fix the sonic boom problem, get fuel economy as a bonus, and we just might see the Concorde II in our lifetimes. LA to Melbourne in under 14 hours? COOL!!!
      • Re:No sonic boom? (Score:5, Informative)

        by AmiMoJo (196126) <[ten.3dlrow] [ta] [ojom]> on Monday March 19, 2012 @03:48PM (#39407187) Homepage

        Actually the banning of sonic booms was more political than based on reality. Boeing had pretty much given up on their supersonic passenger aircraft and the French/British design looked set to rule the long distance market.

        Concord was still an impressive aircraft, cutting flight times to the US down to five hours. Unfortunately it cost a lot to design, build and run, but had it not been effectively banned from many parts of the world those costs would certainly have come down with volume and improvements to the technology. Instead the supersonic passenger jet market was killed before it really started.

        We have been promised radically new aircraft designs for decades but they never seem to come. In many ways Concord was the last big step forwards, everything after that was just a refinement of existing technology.

      • Well, first off, nothing stopped LA->melbourne. In fact, other than a few routes overland (i.e. LA->NYC), there are very few routes passing over land that required supersonic speeds for major savings.
        • by isorox (205688)

          Well, first off, nothing stopped LA->melbourne. In fact, other than a few routes overland (i.e. LA->NYC), there are very few routes passing over land that required supersonic speeds for major savings.

          Europe to anywhere in the east. If it was really about flying over populated areas, and not just a political move, then London/Paris to Japan would have worked (Siberia being fairly empty).

          Concorde's range was limited too, about 4,500 miles. LAX-MEL is 8,000 miles, that's longer than most flights.

          LHR-DXB would have worked distance wise, but is entirely land based. LHR-JFK obviously worked technically, just not commercially. DXB to SIN/HKG/PVG would work, without the ban over land, but is the market there?

      • by rtb61 (674572)

        Wohoo, you'll spend more time being stripped, radiate and sexually probed by the TSA then you will on international flights, hmm, perhaps not so cool after all. So cheap fast flights to the US at a time when it is no longer desirable to do so.

      • by riverat1 (1048260)

        LA to Melbourne if under 14 hours would be cool but you could do it even faster with a sub-orbital ballistic flight, probably under 3 hours. Normal low Earth orbits are about 90 minutes for a full orbit.

        • by jamstar7 (694492)
          At those speeds, you'd spend more time getting through security & customs than you would in flying out.
      • by chrismcb (983081)

        LA to Melbourne in under 14 hours? COOL!!!

        You talk about not being able to fly supersonicly over land... And then you give one of the few routes that doesn't require flying over land?

        • by jamstar7 (694492)

          LA to Melbourne in under 14 hours? COOL!!!

          You talk about not being able to fly supersonicly over land... And then you give one of the few routes that doesn't require flying over land?

          As has been pointed out, Concorde had a 4800 mile range. LA to Melbourne is quite a bit further than 4800 miles. However, the 'Concorde II' might have been designed with longer range, perhaps enough to make the flight nonstop.

    • I grew up right outside (literally the last house to the south gate) of Edwards AFB in the late 80s-early 90s. I miss all the cool aircraft that flew right past our house.

      I watched everything from the B-1, when it was still in flight test, to the maiden voyage of the B-2 from my front yard. Also watched the Space Shuttle a couple of times, when it had to come in on a non-standard approach.

      Living in the middle of the desert, sonic booms were about the last thing we complained about

  • Romulans? (Score:5, Funny)

    by gstoddart (321705) on Monday March 19, 2012 @02:27PM (#39406397) Homepage

    Is it me, or does that look like a Romulan War Bird? :-P

  • http://www.youtube.com/watch?v=70_nQpOQczM [youtube.com]

    Sonic Boom is a charge attack so maybe they are forgetting to charge.

  • by JoeMerchant (803320) on Monday March 19, 2012 @02:31PM (#39406421)

    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.

  • Pshaw. Tom Swift, Jr. solved this years ago: http://en.wikipedia.org/wiki/Tom_Swift_and_His_Sonic_Boom_Trap [wikipedia.org]
  • by TrumpetPower! (190615) <ben@trumpetpower.com> on Monday March 19, 2012 @02:39PM (#39406521) Homepage

    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&

    • by Anonymous Coward

      with a hour of "secure" groping before takeoff and another hour each to get to and from the airport

      Not at the pass classification they would be flying. You pay enough for your tickets or you fly enough and they cut down the lines.

    • by T Murphy (1054674)

      The problem is that supersonic flight requires too damned much fuel for too little gain

      Of course, at altitude the speed of sound is slower, further aggravating the problem of trying not to inch too close to the sound barrier. Although faster subsonic flight could be achieved simply by flying in lower, denser air, obviously the best solution is to take advantage of the speed of sound being many times faster through water and make submersible airplanes. By flying planes through the water, we could save time even going only half the speed of sound, which clearly means we would save fuel too. It

      • by peragrin (659227)

        if your going to fly through the ground you might as well,
        Dig a tunnel,
        setup a maglev train with self contained atmosphere,
        Seal the tunnel and vacuum all the air out of it,
        travel at ridiculously high speeds without air friction slowing you down

    • Sure, shaving 2 hours of a six hour flight time isn't that big of a deal, but there are places outside the US, and sometimes people like to fly there. Cutting 6 hours off the flight from LA to Sydney would make my life significantly more enjoyable when my mother tells me that I have to come visit her lest I be disowned.

    • by Chuckstar (799005) on Monday March 19, 2012 @03:27PM (#39406985)

      Concorde flight time from JFK to Heathrow was closer to 3 hours. And among a very wealthy (or expense accounted) class it was very popular (just not quite popular enough).

      But remember that the biggest impediment to the success of Concorde might have really been that it only made sense to fly JFK Heathrow and JFK de Gaulle. Because of this, few planes were built, eliminating any economies of scale of building or even maintaining them. Also eliminating the possibility of follow-on models -- as it is often the subsequent models where the manufacturer finally gets it "right".

      The reason this is announcement is a big deal, therefore, is that it potentially fixes Concorde's achilles heel -- that it was only allowed to go full speed over water, and didn't have the range to go over water any further than NY to Europe. This plane could fly over land, and have a longer range -- opening the possibility of many more city-pairs, many more sales, therefore economies of scale.

      Having said that, barring a magic bullet like "engineers figure out sure-fire way to make a Mach-2 passenger jet at only 50% higher cost per passenger mile with limited up-front development risk", you are correct that no one is going to spec billions to see if they can make the thing work. Concorde was cool, but a financial boondoggle for Britain and France. Boeing thought about making a (relatively) efficient Mach-0.95 jet, but at the cost of a dramatic departure from traditional airliner design. They decided the risk was too great and went with the more traditionally-shaped 787.

      We're stuck at Mach-0.85 until another government decides to underwrite the development costs. There's just too much risk for a private corporation to take on. They could spend billions and have it just not work.

      The one possibility for this tech, however, is for a really high-end private jet. A guy like Burt Rutan might be able to put together a skunk-works-style prototype of the thing, and then sell copies at a few hundred million a piece. At that price, could probably sell a half-dozen around the world.

      (Note: current passenger jets can reach top speeds above Mach-0.9, but typical cruising speed is right around Mach-0.85.)

      • We're stuck at Mach-0.85 until another government decides to underwrite the development costs

        Go tell DARPA it would make a super-stealthy spy plane. Come back in 2030 for your NY to New Delhi 6-hour flight.

      • by damburger (981828)

        It wasn't that it only "made sense" to to flights to JFK - it is that the US attempt at a supersonic passenger jet was an utter failure, and when UK/France got theirs built first you guys basically through a hissy fit, banned some of the most profitable routes (across the US and back in 1 working day) on the shallow pretext of sonic booms

        (hint: The US isn't exactly densely populated. The problem was manageable even over land)

    • by Anonymous Coward

      It depends at what speed you are flying at. Drag generally decreases once you go past mach 1. Once you get out to mach 3.3 or so, your drag is about the same as flying at high subsonic. This means that your fuel use would be about the same for modern airliners, but you could go from NY to London in about 3 hours.

      There are studies for straight wing high AR transports. These would be slower than a modern airliner but could be more efficient, requriing small engines and not using as much fuel per passenger mil

    • by Sez Zero (586611)

      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.

      That's the whole point of the research, to find out how to fly faster, with less fuel. From the fine article (the MIT release):

      They found that smoothing out the inner surface of each wing slightly created a wider channel through which air could flow. The researchers also found that by bumping out the top edge of the higher wing, and the bottom edge of the lower wing, the conceptual plane was able to fly at supersonic speeds, with half the drag of conventional supersonic jets such as the Concorde. Wang says this kind of performance could potentially cut the amount of fuel required to fly the plane by more than half.

      Cutting fuel requirements by half and cutting drag by half, that's pretty good. Really, the headline is wrong-- they weren't out to remove sonic booms, but how to use and modify an old biplane design that reduces sonic booms to make a more fuel efficient supersonic design.

    • by AmiMoJo (196126)

      That's why high speed rail is a better option for most short and medium haul flights. No security, just get on at a station right in the middle of town and relax in comfort, space and quiet. Luxuries like in-seat power and in-flight wifi are standard, plus you can use your phone and other electronics as much as you like. No luggage limits either.

      Current 320kph speeds are not bad, but mag-lev will hit 550kph easily. I just wish the Japanese would hurry up and build their long distance mag-lev track because,

    • by isorox (205688)

      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.

      Heathrow to Singapore is currently 14 hours. Increase the range, double the speed, and you're saving a lot of money.

      Concorde was never for you and me. It's for people that don't blink about prices. A walk on return fare from LHR-JFK is about $15k. People pay that without blinking.

      Concorde might work if
      1) Range + boom meant you could fly longer, like NYC-SIN/DXB, LHR-DXB, maybe even IAH-DXB. 6 hours New york to dubai rather than 13? Currently Emirates share $20k for that trip. Would people pay $50k to save 7

  • 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....

    • Fuel efficieny is another problem. The Concorde could use as much fuel as a 747 but the 747 could carry 3 times as many passengers. Air France and British Airways simply charged more for Concorde tickets but not all airlines can do this.
      • by peragrin (659227)

        part of that though was afterburners. newer jet engines are supersonic capable without afterburners.

        See F-22 raptor.

        The concord used afterburners to get up to speed and then could use it's regular engines to maintain it.

        The F-22 dones't need afterburners to get to mach 2.

        • The fuel efficiency of the F119s on the F-22 isn't all that better than the Olympus's on Concorde, and Concorde could push all the way to Mach 2 without reheat but it's more fuel efficient to use reheat than not (using reheat means Concorde spends less time in the transsonic region of high drag). What the F-22 has in its favour is its thrust to weight ratio, which is a lot better than Concordes...

          Remember, civil operators have an entirely different set of criteria to military operators, and military operat

        • The size of the plane is another factor. The Concorde could only hold 100 passengers which is pretty small. While engines have advanced, structural engineering has as well. I don't know if it has advanced enough to where they make a much larger plane that could go supersonic without costing too much for it to be competitive. Boeing's 787 is using advanced materials to lower fuel costs but project overruns has started to become evident. And the 787 does not have to factor in supersonic considerations.
        • by rdebath (884132)

          I've worked under the flight path of Concord taking off from Heathrow.

          You are not wrong, the engines are very very very loud.
          The office was specially soundproofed. From the right rooms you could see the planes landing; they are heading straight for you looking like they're rather likely to land in the car park.
          The Smokers (who weren't allowed to smoke in the office) made real sure that they were never outside when the Concord went over.

          It sets of car alarms.

          On a good day shakes your eyeballs, the

  • by dezent (952982)
    Not very much to discuss here is it? Old blade with some text on it.
    • by dezent (952982)

      Not very much to discuss here is it? Old blade with some text on it.

      I was commenting on the wow server, why is my comment here?

  • by damburger (981828) on Monday March 19, 2012 @02:57PM (#39406721)

    At sub-supersonic speeds, a Busemann Biplane doesn't produce sufficient lift under acceleration, undergoing considerable drag.

    Well, that is all well and good - but what happens at super-subsupersonic speeds?

  • 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.

    • by grumbel (592662)

      Given that it will take quite a few years or decades before such planes go into production, it will probably all be done by autopilot by then.

  • 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.
  • by Hsien-Ko (1090623)
    they didn't eliminate flash kick
  • I wonder if there's any way to make a projectile with similar characteristics?

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