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Power Science

Future Ships Could Float On Bubbles 314

Posted by kdawson from the always-knew-champagne-eases-friction dept.
MattSparkes writes, "Creating a layer of bubbles underneath a ship's hull could improve fuel efficiency by 20%. When you consider that 90% of the world's goods are transported by sea, the importance of this discovery is obvious. 'Conjured up from thin air at the flick of a switch, this slippery blanket will help transport a fully laden tanker or container ship across the ocean at higher speed, and using far less fuel, than ever before... There is currently no other technique in naval architecture that can promise such savings.'" The article looks in some detail at the engineering problems that will need to be overcome before this technique is practical.
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Future Ships Could Float On Bubbles More

Future Ships Could Float On Bubbles

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  • other options (Score:5, Funny)

    by User 956 ( 568564 ) on Monday November 27, 2006 @04:31PM (#17007364) Homepage
    Creating a layer of bubbles underneath a ship's hull could improve fuel efficiency by 20%

    But have they tried rainbows and/or fairie dust?

    • Re: (Score:3, Funny)

      by Marxist Hacker 42 ( 638312 ) *
      I was thinking Air Hockey tables. I mean, the tech to do this isn't exactly rocket science, it's more like Disco Science. I think these Japanese Ship Builders probably have an unhealthy obsession with Olivia Newton John...

      • Re: (Score:3, Funny)

        by Andrew Kismet ( 955764 )
        I really hope you've coined a term to be picked up by the world there with "Disco Science".

        • Re:other options (Score:5, Funny)

          by Jah-Wren Ryel ( 80510 ) on Tuesday November 28, 2006 @01:58AM (#17012800)
          Whether you're a sailer or whether you're a freighter,
          You're stayin afloat, stayin afloat.
          Feel the bubbles breakin and everybody shakin,
          And were stayin' afloat, stayin' afloat.
          Ah, ha, ha, ha, stayin' afloat, stayin' afloat.
          Ah, ha, ha, ha, stayin' afloat.

          Well now, I get low and I get high,
          And if I can't get either, I'm still dry .
          Got the winds of heaven on my shoes.
          I'm a bubblin' man and I just can't lose.
          You know it's all right. It's ok.
          I'll sail to see another day.
          We can try to understand
          The disco science effect on man.

          Boat's goin nowhere. somebody help me.
          Somebody help me, yeah.
          Boat's goin nowhere. somebody help me.
          Somebody help me, yeah. stayin afloat.

          Well, you can tell by the way I use my walk,
          I'm a sailin' man: no time to talk.
          Bubbles loud and waves are warm,
          I've been tossed around since I was born.
          And now it's all right. It's ok.
          And you may look the other way.
          We can try to understand
          The disco science effect on man.

    • Re: (Score:3, Funny)

      by pilgrim23 ( 716938 )
      Lawrence Welk where are you now that we need you?
    • This sounds like a lot of Hot Air! Pshh...
    • IBM tried Fairy Dust and it resulted in them selling off their hard drive business and their hard drive being nicknamed the DeathStar.

    • Re: (Score:2)

      by tehshen ( 794722 )
      But have they tried rainbows and/or fairie dust?

      No, but they tried Blossom and Buttercup.
    • But have they tried rainbows and/or fairie dust?

      I think that would be fair game for their proposed penis boat.

  • But how will it affect buoyancy? (Score:4, Interesting)

    by with_him ( 815684 ) on Monday November 27, 2006 @04:32PM (#17007386)
    Since methane hydrates releases are still suspected in the sinking of ships, how do the researchers account for the loss of buoyancy? Since this research calls for redesign of current ship building know-how, how are they planning on addressing the buoyancy part of the equation? To read more check out this http://www.newscientist.com/article.ns?id=dn1350 [newscientist.com] and http://jbj.wordherders.net/archives/000992.html [wordherders.net] someone trying to weaponize the buoyancy concept. http://www.nexusresearchgroup.com/fun_science/buoy ant1.htm [nexusresearchgroup.com] A fun science experiment for the kiddies, or others that want to understand it better.

    • Re: (Score:3, Interesting)

      by DilbertLand ( 863654 )
      With methan hydrate releases the theory is that the entire volume of water surrounding the ship is "full of bubbles" and has an effectively lower density. What they are talking about here us just surrounding the hull with a thin layer of bubbles.....maybe the ship sits a couple inches (to pull a guess out of my rear) lower in the water....but there's not going to be any danger of sinking a ship...

      • Actually it floats HIGHER (Score:5, Informative)

        by Ungrounded Lightning ( 62228 ) on Monday November 27, 2006 @06:02PM (#17008824) Journal
        What they are talking about here us just surrounding the hull with a thin layer of bubbles.....maybe the ship sits a couple inches (to pull a guess out of my rear) lower in the water....but there's not going to be any danger of sinking a ship...

        Actually it floats HIGHER - by about the thickness of the air film. (It would float higher by EXACTLY the thickness of the air film except that the film is compressed slightly by the higher water pressure at the bottom of the boat.)

        To understand it:
          - The film displaces water, just like the hull.
          - If the hull sinks marginally, the film stays about the same thickness and it's the water below that is displaced.
          - So the film of air acts like part of the hull.
          - The total amount of water displaced is the amount displaced by the hull PLUS the amount displaced by the air.
          - But the air under the boat is about the same density as the air above the boat. So only the craft's weight (plus any surplus weight of air from its compression by the higher pressure below the hull) is supported by the displaced water.
          - Thus, to displace its own weight the hull plus air system must have the hull higher than the hull-only system by about the thickness of the air barrier.
    • those are releases on a vast scale, so much so that the ship no longer has sufficient mass of water around it to stay on the surface, and it lowers to its new level, which is far too low under the surface for survival. I don't think it's the same thing at all.

      The same concentration reaches up into the sky and causes planes to go boom impressively it is beleived. The hypothesis being that the reduced density of the water causes the fragments to also sink below the surface instantly, which is why there is no

    • Re: (Score:3, Funny)

      by Da Fokka ( 94074 )
      No, shipping companies are expected to invest heavily in ships that sink.
    • The Shkval torpedo is the one weapon that I remember hearing about a couple years ago that used bubbles to reduce friction. Crazy stuff... who would have imagined that bubbles would help build a better weapon?

      http://en.wikipedia.org/wiki/VA-111_Shkval_torpedo [wikipedia.org]
  • Layer of Bubbles? How can Michael Jackson decrease fuel consumption.
  • The theory being that the air bubbles help reduce the noise hence they're more silent to passive sonar systems on submarines, useful for anti-submarine warfare.
    Or did I read it in a Tom Clancy book? Probably a little from column a and a little from column b.
  • With this knowledge, no one will be able to touch my son's boat at the next Boy Scout's boat race!!!

  • The technology already exists! (Score:3, Funny)

    by GoRK ( 10018 ) on Monday November 27, 2006 @04:42PM (#17007554) Homepage Journal
    Why bother reinventing the wheel when they could just glue a bunch of air hockey tables to the outside of a boat?

  • no other technique??? (Score:5, Funny)

    by DerekTomes ( 1024783 ) on Monday November 27, 2006 @04:43PM (#17007564)
    "...There is currently no other technique in naval architecture that can promise such savings..."
    Except sails.
    • Damn, where are my mod points when I need 'em.

      Well, I give this a +1 funny and a +1 insightful!

      Hmm, then it might be too high, might have to give it a -1 overrated too.

    • Re: (Score:2, Insightful)

      by dfenstrate ( 202098 ) *
      Sails and tight schedules don't go well together.

      • Re:no other technique??? (Score:5, Informative)

        by AK Marc ( 707885 ) on Monday November 27, 2006 @05:02PM (#17007932)
        They go great together. When you have the wind, you raise the sails and turn the engines down. When you don't have the wind, you take the sails down. You have the same speed either way and are never off schedule. The difference is that you get there using less fuel when you use the sails in addition to the engines.

    • Re: (Score:2)

      by qwijibo ( 101731 )
      Sails don't sell oil you hippy. =)

      I'd like to see blimps used for non-time-sensitive over land shipping. I saw an article in popular science many years ago talking about the feasability of blimps for moving things as large as tanks. For non-wartime/non-hostile equipment movement, it seems like that would have to be cheaper than ditching everything and replacing it later.

      • Re: (Score:2)

        by jandrese ( 485 )
        Blimps are real gas guzzlers if you're going against the wind though. Even if you're going with the wind I doubt there are any savings at all compared to freight trains, and they're slower than trains to boot. Using blimps for shipping just doesn't seem like a good idea to me, unless you're shipping to some area that doesn't already have infrastructure (out in the middle of nowhere), in which case it would probably be more fuel efficient than the helicopters/light aircraft you would otherwise have to use.

      • Re: (Score:2)

        by Bertie ( 87778 )
        Yeah. Check these guys out.

        Airships with a twist. Part of the lift comes from aerodynamic lift, which means you can land 'em. And I don't know whether they've actually built it yet or not, but they were talking about making a military-spec job with a 1,000-ton payload. Or, if you want to think about that another way, sixteen Challenger 2 tanks. That's some big liftin'. Much faster than road freight, much more fuel-efficient than air freight, much more flexible than rail freight. Slightly vulnerable t

    • Re: (Score:2, Insightful)

      by ductonius ( 705942 )
      Except sails.

      That wouldn't be saving energy, that would be collecting it from an ubiquitous source. A sailing ship equipped with systems this research develops would outperform one without them.

      Somehow using wind to suppliment conventional fuels is a good idea though. Why pay for what you can get for free?
      clicky --> http://www.skysails.info/ [skysails.info]

    • Re: (Score:2, Informative)

      by beyobe ( 679015 )
      Or kites [kiteship.com]?

    • Re: (Score:2, Interesting)

      by merreborn ( 853723 )
      How large of a sail would it take to provide worthwhile trust to a 100,000 ton container ship, I wonder?

      A 170 ton Schooner uses 700 square feet of sail...

      Assuming a linear sail:weight relation, that'd mean 400,000 sq feet of sail. Over 600 feet square. I wonder how your average sail material would hold up when scaled that large; additionally, what sort of mast and rigging would be required? How would you adjust the sails, anyway, when the deck is covered in thousands of 40 foot containers? Would all of

  • Bzzzt (Score:5, Informative)

    by Dan East ( 318230 ) on Monday November 27, 2006 @04:48PM (#17007672) Journal
    When you consider that 90% of the world's goods are transported by sea

    Bzzzt. The submitter misstated the article, so this statement is flat out wrong.

    From the article (emphasis mine):
    in 2003 more than 90 per cent of all goods that were sent around the globe went by ship

    So in the context of global shipping, 90% of goods are transported by sea. Obviously far, far less than 90% of the world's goods are transported globally in the first place.

    Dan East
    • Obviously far, far less than 90% of the world's goods are transported globally in the first place.

      Yeah, but they're working on that, too...

      • Just looking at oil (not dry goods like most metals, grains, and coal), there are about 600 big tanker ships that essentially sail about 330-350 days a year (depending on how long their voyage is and how long it takes to fill and empty them). Each ship burns about a ton of oil per sailing day, so if this reduced usage by the 30%-40% it would greatly reduce pollution in the Oceans (and about 100 gallons per day per ship). Not bad for something as simple as blowing a few bubbles outside the ship's hull.
  • I could have sworn I heard about this idea years ago. I think it could have been 6 years ago. I remember something about this.
    • The first I ran across a similar concept (and one mentioned in TFA) was, in fact, on slashdot. It might have been this article [slashdot.org], though that references earlier stories I couldn't find in a quick googling. Of course, the Scientific American article the /. writeup links to is MIA, so I can't be sure that's the blurb I'm thinking of.

      But yeah, if you've been reading /. for long enough, you've seen something like this before.
      • Unfortunately, archive.org doesn't even have it due to the robots.txt exclusion.

        I sure wish someone would invent a way to surf the Internet in the past.

  • In case anyone is interested (Score:5, Interesting)

    by noewun ( 591275 ) on Monday November 27, 2006 @04:50PM (#17007714) Journal
    In what

    The idea of air cavities has much in common with supercavitation, in which a submerged object such as a torpedo creates a single large bubble around itself. This slashes skin friction, bringing remarkable speeds within reach (New Scientist, 22 July 2000, p 26). Perhaps not surprisingly, Russian engineers who first developed supercavitating torpedoes have not only done plenty of research on air-cavity lubrication for ships, but have also put their ideas to work.

    refers to: Shkval [fas.org]. Scared the bejesus out of the U.S. Navy.

    • The supercavitational bubble is vacuum, not air. This is also the reason why the torpedo cannot be manoeuvred with traditional means once fired (since there is no water anywhere around it).

      • Re:Not really the same. (Score:4, Interesting)

        by PWNT ( 985141 ) on Monday November 27, 2006 @05:35PM (#17008440)
        The supercavitation bubble negates the need for torpedoes that can steer.

        Ships move slower than traditional torpedoes, however the relative difference is not huge, so a ship can attempt to evade the torpedo.

        These new torpedoes travel so fast, that any amount of evasion is useless! IIRC the new torps are travelling at 200 knots, like 400 km/hr or something. This is a huge difference compared to older slow torpedoes travelling at 50 knots.

        These very fast torpedoes would be used to sink the larger fleet carriers from submarines. Get under or anywhere near the carrier, shoot 3 at the carrier and go on a silent run to creep away.

        • Re:Not really the same. (Score:4, Interesting)

          by Anonymous Coward on Monday November 27, 2006 @06:11PM (#17008950)
          These new torpedoes travel so fast, that any amount of evasion is useless!

          They are so fast you can't "see" them coming on sonar. LIDAR doesn't have very good range under water and RADAR doesn't work at all. If it was fired from enough below the surface that the shock wave doesn't hit the surface before you're hit, you'll never know it was coming.

      • FTFA linked by grandparent: [fas.org]

        The solid-rocket propelled "torpedo" achieves high speeds by producing a high-pressure stream of bubbles from its nose and skin, which coats the torpedo in a thin layer of gas and forms a local "envelope" of supercavitating bubbles

        Gas. Not vacuum. The first thing I thought when I heard about the Shkval [fas.org] is "I wonder if the technology could be useful at ship-sized scales?", the first thing I thought when I saw the article here on slashdot was "Woo, supercavitating!"

    • Re:In case anyone is interested (Score:5, Informative)

      by phayes ( 202222 ) on Monday November 27, 2006 @05:34PM (#17008432) Homepage
      <blockquote><i>refers to: Shkval [fas.org]. Scared the bejesus out of the U.S. Navy</i></blockquote>

      Uh, no. To see underwater you use sonar, but the shkval's propulsion is so noisy that it is essentially blind once launched. It's major utility was as a nuclear tipped revenge weapon. Don't forget that when the shkval was being developped, russian subs were relatively deaf & noisy compared to the US & the UK. In that scenario, when a Russian sub discovered that it was being targeted by an unavoidable torpedo, launched from a sub they hadn't detected, they would launch a few shkvals back up the vector that the torp was detected on. Hopefully one of them would take out the opposing sub or at least cut the wires that are used to direct the torp from the sub. An autonomous torp is easier to shake than one that has a subs sonar directing it so cutting the wires gives the russian sub a better chance. Once Nato was aware of the shkval, attack doctrine was changed to include a quiet swim out & dogleg so that the shkval would be targeting the empty sea & not the Nato sub.

      Using a shkval also means nuclear first use, which both sides wanted to avoid.
      • I don't think the Russians really deployed the Shkval on a large scale because it was not a paragon of reliability, mostly due to the liquid-fuelled rocket motor. Some have said the sinking of the Kursk some years ago was caused by a the rocket on a Shkval exploding inside the torpedo room.

  • This works best at slow speeds (Score:5, Interesting)

    by nels_tomlinson ( 106413 ) on Monday November 27, 2006 @04:51PM (#17007720) Homepage
    I haven't yet read the fine article. I do know just a bit about naval architecture. This should help with skin friction, which is the big deal at low speeds. For higher speeds, the resistance which comes from making the wake is the big deal, since the wave-making resistance increases roughly as the square of the speed.

    So, what's ``low speed?'' That's probably going to be any speed much below sqrt(waterline length in feet), with units of knots. So, for a 400-foot long ship, anything less than 20 knots is in the speed range where this is likely to matter. For a 900 footer, anything less than 30 knots. Most ships travel in that low speed range, so this could be practical.

  • Kodama is director of the Advanced Maritime Transport Technology Department at Japan's National Maritime Research Institute (NMRI) in Tokyo. His work is just one of several major programmes under way in the US, Russia, Japan and Europe that focus on how to make ships more slippery.

    Based on my experience in the bathtub, an easy way to make a more slippery craft is to cover it with soap. I think this would scale up nicely, but I'm not sure how they would make a freighter in the shape of a rubber duck.

    • Funny you should say that.

      Have you ever tried to use soap in salt water? It just doesn't work. It's not slippery, it's more like trying to wash with a pumice stone.

      I had the opportunity to try this while sailing to Bermuda when the wind died completely. Hoped to get a nice bath after three days of no showering, but it didn't work.

      • I had the opportunity to try this while sailing to Bermuda when the wind died completely. Hoped to get a nice bath after three days of no showering, but it didn't work.
        you used the wrong soap... there are soaps designed for use with sea water... just google for it... yeah, I know you were caught out, but next time... take some along and you can then save your precious fresh water for drinking.
  • Phah! Bubbles? That's lame. Tenacious D seemed to have an even better idea when they toppled City Hall [azlyrics.com]

    The second decree: no more pollution, no more car exhaust, or ocean dumpage. From now on, we will travel in tubes! Get the scientists working on the tube technology, immediately!

  • Barking up the wrong tree (Score:5, Funny)

    by Control Group ( 105494 ) * on Monday November 27, 2006 @05:04PM (#17007956) Homepage
    What they ought to do is replace the oceans with frictionless liquid helium. That would be way more effective.
  • Or does one big bubble not count?
  • and using far less fuel, than ever before...


    20% increase in efficiency will result in the consumption of "far less" fuel? Far out!

  • when he bubbles up out of the ocean then?
  • Seems to me the most bubbles I see when I'm on a big boat are off the stern, created by the engines and hull displacement themselves. If there was a way to channel those bubbles to the bow of the ship, you may not need extra engines/bubble makers on the front. Perhaps something like an in-hull channel that forces the bubbly soup from the stern up and under the ship, and ejects in under the bow. Either that or find a way to make the ships "Front-wheel drive" so to speak, and have the engines under the bow of

  • Bathtub bubbles (Score:5, Funny)

    by kitzilla ( 266382 ) <paperfrog&gmail,com> on Monday November 27, 2006 @05:17PM (#17008184) Homepage Journal

    "Junior! What are those bubbles in the bathtub?"

    "Just reducing drag, Ma."

  • Vikings already did it (Score:3, Interesting)

    by TeknoHog ( 164938 ) on Monday November 27, 2006 @05:39PM (#17008492) Homepage Journal

    TFA says the most promising method of getting the air cushion is to build cavities on the underside of the ship. It takes some energy to maintain the cavities full of air, but it's a lot less than the energy required for the other methods.

    However, the Vikings used the same principle centuries ago. Their way of building ships [wikipedia.org] creates longitudinal grooves along the bottom of the hull, which form cushions of air at higher speeds. The overall shape of the hull also contributes to low resistance. I don't have any proper references, as I only saw this in a documentary once, but for example here [imperialoil.ca] is a brief mention of the idea.

  • There is currently no other technique in naval architecture that can promise such savings.

    But this one does? Promises 20% savings? I wonder if there's a hat ready to be eaten by the author. It's a really bold promise anyway.

  • Not really a new idea. (Score:3)

    by Anachragnome ( 1008495 ) on Monday November 27, 2006 @05:58PM (#17008742)
    The idea, while novel, is not new. The idea of a "100 knot Torpedo" has been around for awhile. The idea was to basically blow compressed air through a nozzle in the nose of the torpedo enveloping the torpedo in a "shroud" of air, as opposed to water, thus drastically reducing drag resulting from moving through the water.

    The idea, when applied to a ship, has nothing to do with bouyancy(although it would certainly effect it) but rather reducing drag by displacing the water around the hull with air. While impossible to entirely remove the contact with water, even small decreases will reduce drag enough to make the whole idea worthwhile in terms of fuel consumption.

    The problem with BOTH ideas is the interference with propulsion. A propeller does not work as efficiently in the same mass of air bubbles. Unless some means of keeping the prop out of the bubble cloud is devised, the resulting loss of propulsion will offset the gains made by the reduction of drag. This is the main reason the "100 knot Torpedo" is not used.

    As far as noise reduction in submarine warfare, it is NOT quieter. Its simply different. It is akin to a propeller "cavitating", and in submarine warfare, that is like sending up a signal flare.

  • How does the ship floats if it's surrounded by air? If it can "float" on thin air, why can't it "float" on "thick air", i.e. "fly"?

    I have heard of such a technique several years ago for torpedoes. But those torpedoes go fast and have wings still in contact with the water to provide the lift.

  • The Prairie/Masker [fas.org] has been used for a while to reduce the acoustical signature of ships conducting anti-submarine warfare.

  • "The article looks in some detail at the engineering problems that will need to be overcome before this technique is practical."

    For get the engineering problems, what about the financial problems. Mr. Bubble ain't cheap ya know...
  • How about reducing craps flying out of China? Surely that oughta reduce great deal on shipping fuel and save the "free market" from 3rd world countries' ridiculous low manufacturing and living cost.
  • More idiots adding more sh!t to the environment. We've already seen how the ocean provides the particulates and the water vapor for the clouds that keep the planet from going supernova...

    I dislike greenies as much as the next guy, but adding polymer ejaculates to ships - battleships, ships of war, or just ships that have to go fast, to make them go faster or use less fuel.... ffs wtf are the thinking!?

    From TFA: "The polymers probably won't damage the environment"

    Let's start a famous quotes page, he

  • Flapping Tails (Score:5, Interesting)

    by Garrett Fox ( 970174 ) on Monday November 27, 2006 @07:24PM (#17009840) Homepage
    It's also worth looking at MIT's RoboTuna and RoboPike [mit.edu], robotic fish, and the penguin boat Proteus [mit.edu]. These projects demonstrate that fish-like fins or flippers substantially improve propulsion efficiency vs. propellers, because they generate vortices of water that actually push a vehicle forward. MIT sees these vortices as the answer to Gray's paradox [arstechnica.com], which said that a dolphin would have to be stronger than it is to swim as fast as it does. (That article disagrees.)

    A flapping drive would also have the advantage of looking cool.

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