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Science Technology

DARPA Creates Machine Which Extinguishes Fires With Sound 121

SchrodingerZ writes "The Defense Advanced Research Projects Agency (DARPA) is known for making odd scientific advances ranging from hypersonic unnamed rockets to bionic prosthetic limbs to insect-sized reconnaissance drones. But recently DARPA has made a interesting advancement in the field of fire suppression. Using two speakers arranged on either side of an open liquid fuel flame, an acoustic field was emitted and engulfed the fire. 'The sound increases air velocity, which then thins the area of the flame where combustion occurs, known as the flame boundary.' This make the flame weak and much easier to douse. Another wonderful thing about this: it's not even that loud! DARPA began its testing in 2008, stating that despite extensive research in this area, there have been no new methods for extinguishing and/or manipulating fire in almost 50 years. The agency plans to expand on this experiment and try to make it successful on a practical scale."
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DARPA Creates Machine Which Extinguishes Fires With Sound

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  • by Anonymous Coward

    ...would be so difficult?

  • by Shandon ( 53512 ) on Sunday July 15, 2012 @11:10PM (#40660079)

    The Mythbusters did that already, in Episode 76 ( So we know that works already...

  • Rockets? (Score:4, Funny)

    by GodGell ( 897123 ) on Sunday July 15, 2012 @11:10PM (#40660081) Homepage

    Hypersonic unnamed rockets? Wait until Anonymous hears about that...

  • CO2? (Score:4, Interesting)

    by sonamchauhan ( 587356 ) <<moc.liamg> <ta> <cmanos>> on Sunday July 15, 2012 @11:17PM (#40660105) Journal

    "The team arranged two speakers either side of a liquid fuel flame to demonstrate how fire can be controlled by amping up an acoustic field. The sound increases air velocity, which then thins the area of the flame where combustion occurs, known as the flame boundary. Once the boundary area is thinned, the flame is easier to extinguish. "

    Pardon my scepticism, but if you can position speakers at the base of a flame, you can also position CO2 nozzles there too.

    BUT - this could be significant - a robot carrying speakers does not need to carry a CO2 gas supply.

    Or they could the two techniques in combination -- using an accoustic field to shape a CO2 extinguishant stream that manipulates the "flow of cold plasma" feeding the flame.

    • Re:CO2? (Score:5, Insightful)

      by Anonymous Coward on Sunday July 15, 2012 @11:35PM (#40660169)

      Quenching a fire in a submarine would probably be far less problematic if you could use sound instead of gases.

      • Re:CO2? (Score:4, Interesting)

        by sumdumass ( 711423 ) on Monday July 16, 2012 @12:44AM (#40660415) Journal

        Also, think about utility corridors in large building where an electrical fire or something of the sorts are a danger. Using gasses or toxic chemicals might present a danger to humans still inside the building. Mount a few rails with speakers connected and send them to the hot spot as needed.

        Or use something like this [] and line evacuation routes people would take in case of fire helping ensure an open escape path for longer periods of time.

      • by treeves ( 963993 )

        Gases are not used to put out fires on submarines. Water is used.

    • Re:CO2? (Score:5, Informative)

      by Unkyjar ( 1148699 ) on Sunday July 15, 2012 @11:56PM (#40660271)

      "The Instant Fire Suppression project was specifically launched to devise new ways of tackling fires in enclosed spaces, such as aircraft cockpits and ship holds, where fires are obviously devastating and incredibly difficult to control." - TFA

      • Re:CO2? (Score:4, Insightful)

        by Anonymous Coward on Monday July 16, 2012 @12:46AM (#40660425)

        AKA: Submarines. Navy just had a very expensive submarine fire. If they could simply install speakers, they could avoid a very expensive fire suppression retrofit. Risk of crew suffocation and equipment damage are always present with chemical or gas based systems.

        • by Anonymous Coward

          ...Navy just had a very expensive submarine fire...

          I knew that. Now I feel bad. I suspect everyone that is here to read this has already at least heard about it seeing as it was here:

          It is a sad day when an AC three quarters of the way down the page got it before anyone else. He should be modded insightful so everyone can smack themselves on the forehead for not noticing and feel bad as me about it.

        • And that fire was problematical because the ship was in the shipyard and normal services and access was disrupted. I.E. it's very unlikely the speakers (which only weaken the flame) would have been very useful. Not that there's room for the speakers anyhow.

          And the dangers of chemical or gas based systems is why the main firefighting system is water.

          (Disclaimer: Former submarine crewman.)

          • How about bending and confining flames using electromagnetic waves and then weakening them? Would that help?


            "The electric field it emits achieved this by creating an ionic wind that displaces the combustion zone from the fuel source.

            Being able to bend flames might seem like a very cool but ultimately useless method of firefighting, however the system will come in handy when fires rage out of control in enclosed spaces "the flames can be redirected to provide safe passage, if they cannot be extinguished

            • How about bending and confining flames using electromagnetic waves and then weakening them? Would that help?

              Not really. If you can get access to setup an electronic gadget, you can get access to get water on the flames or the seat of the fire. (Ultimately, onboard a submarine, access is the key issue in firefighting. ) If we need to redirect flames to allow safe passage (an unusual and unlikely event), we use a fog nozzle - which is not only very effective, but can with the twist of a valve switch to a s

      • by magsk ( 1316183 )
        Difference between gases and sound waves is that gas can get around obstacles and into small crevices, sound waves cannot. Unless the fire is direct line of site and close to the fame in the video demonstration then it will not work. Put a simple piece of plywood or sheet metal in front of the speaker and fire and watch nothing happen.
    • Re:CO2? (Score:4, Insightful)

      by drinkypoo ( 153816 ) <> on Monday July 16, 2012 @12:41AM (#40660401) Homepage Journal

      BUT - this could be significant - a robot carrying speakers does not need to carry a CO2 gas supply.

      Robot carrying speakers has to run back and forth dropping speakers. Speakers which are robots, much better.

      • or speakers carrying robots...that get out of the speaker and try to trample on a fire when it breaks out.

    • Or next time a wildfire approaches my house, I'll just stick speakers out the window and start playing loud music.

    • Re:CO2? (Score:5, Insightful)

      by DarwinSurvivor ( 1752106 ) on Monday July 16, 2012 @04:09AM (#40661027)
      Acoustic fire suppression also leaves a LOT less mess behind. Think server rooms, restaurants and print shops where the fire suppression system typically causes about as much damage (in that area) as the fire itself.
      • This system may put out open flames, but it's not going to do anything about heated gases or smoldering combustion, and I don't think it'll do much to prevent reignition, flashover, backdraft, etc.

      • That brings up an interesting question, I wonder the effects on sensitive equipment such as in a server room from such high energy harmonic devices?

  • by Anonymous Coward

    Seriously DARPA, get on to something we REALLY need.

  • Just around the corner.

  • high altitude (Score:2, Interesting)

    by fonitrus ( 1763632 )

    thin air on demand could be nice for high altitude training without going to the mountains and just make these simulated high altitude training centres in local urban areas. lowering the training costs for athletes both in travel and being away from family.

  • I freakin love unnamed rockets!

    • by azalin ( 67640 )
      But how do you distinguish them if there are several versions?
      • unnamed, not unnumbered

        • by azalin ( 67640 )
          But if you number it, isn't the number effectively the name? I mean "459134" doesn't have the same ring as "Hellfire" but it still is a unique alphanumeric identifier. Only harder to remember and more error prone. ("Fire two 445s is said! The training missiles! And you fired a 2445 TacNuke! We are all doomed...")
          • by azalin ( 67640 )
            On a more amusing note, strapping four ICBMs under an Apache (or is it strapping an Apache on the ICBM?) might require the use of more than a few rolls of duct tape. That's a mental image to cherish.
  • I guess that's why they never called me back. I just set fire to the speakers. OK, the sound extinguishes the *fire*, got it.
  • by Anonymous Coward


    Filter error: Don't use so many caps.Lameness filter encountered. Post aborted! Filter error: Don't use so many caps. Filter error: Don't use so many caps.

  • by Black Parrot ( 19622 ) on Monday July 16, 2012 @01:27AM (#40660535)

    It also kills everyone within 100 meters of the fire.

    • by jamesh ( 87723 )

      It also kills everyone within 100 meters of the fire.

      But the fire does get extinguished, right? Don't bother us with the minor details.

      • Dr. Zoidberg: I'll simply put you into a high-velocity centrifuge and centrifugal force will separate the denser king of Trisol out of your body.
        Fry: Won't that crush my bones!?
        Dr. Zoidberg: Ahhh, yes the bones... I always forget about the bones!

        What was going to be a pleasant afternoon of drugs and surgery has not gone as planned. Well we still have three or four healthy co-workers with PLENTY of spare parts.

    • You joke, but I can't help but think of the military applications of being able to redirect or extinguish flames at will. []

  • by Anonymous Coward

    Pfffft! Prior art exists! Sound extinguishes fire..i know it already.. dear wife yells and all my fire gets extinguished.

  • by Gravis Zero ( 934156 ) on Monday July 16, 2012 @02:30AM (#40660747)

    there's an app for that.

  • It's actually with air! Or, better, with pressure waves in the air.

  • ...says TFS while linking to a video of two speakers, each about four times the size of the flame. Given the low frequencies that such large speakers can produce, it's more about wind than sound. So DARPA figured out that you can put out a fire by blowing on it. That's tax money well spent.

  • MC: Somebody call the medics, the crowd is on fire!
    Hendrix: Hang on, I got this . . .
    Cue Purple Haze

  • Is a ST:TNG tech manual, carefully annotated and checkmarked.

  • Where they put them out by detonating sticks of dynamite above the burning well head. But on a much smaller and more manageable (albeit less fun) level.

  • None of them have a power supply capable of running more than a few seconds if they even have a battery in them at all. the one in that photo is just an artist fapping his mind on a concept.

    They cant break physics, and current batteries, even the high end NASA ones cant store enough power and be light and small enough to even make the wings on that thing move slightly.

    • I think it won't be long until we have nanotech that will enable aerogel style chambers to contain lighter then air gas. Such a neutral boyant structure of a semi-conductor latice could also perform as a capacitor and maybe even have a photovoltaic exterrior and intigrated circuit inside. It's wings could also be used as a as a directional microphone diaphram

  • The Internet. We should probably mention this, as well as a refresher:

    • its - an irregular possessive. "The serial killer wants its victim now."
    • it's - a contraction of it is. "It's time for the victim to step forward."
  • I wonder if something like this could be used inside an engine's combustion chamber to prevent preignition. That could allow for more compression/boost.

  • Muaaaaaaaaaaaaad'Dib!

    "Some thoughts have a certain sound, that being equivalent to a form. Through sound and motion, you will be able to paralyze nerves, shatter bones, set fires, suffocate an enemy or burst his organs."

    It seems logical if one word can set fires, another could put them out.

  • Looks like there will be a new iPhone application in app store soon...

  • to insect-sized reconnaissance drones.

    'The sound increases air velocity

    Use four insect drones to 3D triangulate the position of mosquitoes, which have a unique visual signature in flight. Use a synchronized sound burst from three to push a mosquito directly into the path of a synchronized infrared laser pulse from the fourth, which heats and kills it. Repeat. Good-bye malaria.

Remember to say hello to your bank teller.