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What Scorpions Have To Teach Aircraft Designers

Posted by samzenpus on from the taking-the-sting-out dept.

First time accepted submitter elloGov writes "The north African desert scorpion, Androctonus australis, is a hardy creature. Most animals that live in deserts dig burrows to protect themselves from the sand-laden wind. Not Androctonus; it usually toughs things out at the surface. Yet when the sand whips by at speeds that would strip paint away from steel, the scorpion is able to scurry off without apparent damage thanks to the unique structure of its carapace. Dr Han Zhiwu of Jilin University and colleagues have found that surface irregularities based on the scorpion's exoskeleton could substantially minimize atmospheric dust damage to aircraft."

9 of 127 comments (clear)

  1. What about drag by Anonymous Coward · · Score: 1, Interesting

    A lot of work has been done lately on getting very smooth aerodynamic surfaces, because when you promote laminar flow, you can get very significant decreases in drag. Wouldn't this additional surface roughness mess that up?

    1. Re:What about drag by Narcocide · · Score: 4, Interesting

      I'm not sure but I think, not necessarily. They add dimples to golf balls to increase their flight distance and straighten their flight trajectories specifically to disrupt laminar flow, because over a sphere, turbulent flow actually can work better, if the dimples are just the right size and have just the right irregularity. I don't know for sure if it can be applied to aircraft though; maybe it only works on golf balls. Reference here.

    2. Re:What about drag by berashith · · Score: 5, Interesting

      Mythbusters did it to a car, and increased gas mileage. This was just using clay. If someone used decent materials, there is likely a huge gain to be had in performance. Of course, the surfaces on a plane NEED to interact with the air, so too much disturbance may not be a good thing.

    3. Re:What about drag by Tastecicles · · Score: 4, Interesting

      Doesn't seem to affect the flight characteristics of the F117A Nighthawk any... they use reinforced carbon-carbon laminate (which has a rough profile when the resin substrate sets) on its flight surfaces, not just for its physical properties (lightweight, immensely strong and very flexible), but also because that rough surface disperses RADAR and gives a fifty thousand pound strike aircraft the RADAR signature of a sparrow.

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    4. Re:What about drag by Anonymous Coward · · Score: 5, Interesting

      When I was young a friend of mine, an aviation mechanic once told me the properties of how a plane flies. He then proceeded to say the armed forces ignore that and use the philosophy "put enough power behind it, anything can fly"

    5. Re:What about drag by wvmarle · · Score: 3, Interesting

      In this scorpion-skin situation I wouldn't be surprised if the surface drag is reduced.

      Two reasons. The first is that the skin reduces erosion by the sand, which implies to me that the sand is kept away from the skin, again suggesting a thicker boundary layer, and that may decrease drag forces.

      The second reason: the shark skin effect. A while ago there were these shark skin swimsuits, purportedly increasing the performance of swimmers by reducing surface drag. The shape of a shark (and most fish) are similar to aircraft in that they are highly streamlined and have little wake, making surface drag again dominant. If that works in water, it could also work in air.

      Anyway it sounds like a straightforward experiment to test this: create two identical shapes (ball, wing, whatever), one with a polished surface and one with a dimpled/scratched surface, and put both in a wind tunnel. With or without sand.

  2. Shark Skin by drainbramage · · Score: 3, Interesting

    Shark Skin is not smooth, but it has low friction in a fluid, in one direction.
    I recall seeing a promo video from a company that applied such a surface to an Americas Cup boat hull.
    Possibly what you are thinking of.

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  3. Re:That's one plane looking brick... by butalearner · · Score: 3, Interesting

    Note that instability is actually desirable on planes like the F-117, and has been designed in since at least the F-16. The more stable a fighter jet is, the less maneuverable it will be. But also note that instability (especially spiral mode) can be mitigated by the pilot, depending on the severity and which control surfaces are available.

  4. Re:That would be cool... by iamhassi · · Score: 5, Interesting

    ...if scorpions could fly.

    G.

    Exactly. How exactly does the scorpion using bumps on their skin to be less aerodynamic apply to airplanes? Planes already exist with "shark skin" texture to reduce drag, there was even a Mythbusters episode about it.

    And why does the wikipedia article read exactly like this news story? "Androctonus australis is a hardy North African desert scorpion. Unlike Most other animals that live in deserts, Androctonus does not dig burrows to protect itself from a sandstorm. Instead, it can withstand sandstorms powerful enough to strip paint off steel, without any apparent damage."

    Really? That's the best first three sentences for a encyclopedia entry of this creature? Other animals include a detailed description and locations they are found. Strange that the Wikipedia entry was created just 6 days ago.

    Methinks slashdot and the economist has been duped by this "first time accepted submitter" elloGov

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