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Quadcopter without propeller (with hidden propeller)

  1. Jun 7, 2012 #1
    Hello everyone,
    First, I'm sorry about my bad english, if something you don't understand correctly, please ask me, so I'll try to explain it.

    My idea is a quadcopter without propellers, actually the propellers are hidden. This idea comes from this video. It's a "bladeless fan" or an air multiplier.

    So far I think the quadcopter will need lots of energy. But what if this air multiplier is stronger than normal fan/propeller, I think it's still worth to make one.
    Is it possible that a quadcopter can fly with this technology? What do you think?
  2. jcsd
  3. Jun 28, 2012 #2
    How can this be? Those things use a propeller to pull in the surrounding air and blow it through the structure which has an aerodynamic shape that directs it outward, hence major efficiency losses. So there is no way it could have more thrust than the thrust created from a direct drive system.

    Its like the Siemen's hybrid aircraft which uses a gas engine to drive an electric engine in order to fly. Its like using an extended grip to grab a pencil in order to write your homework. See where this is going?

    I'm guessing in theory there is a possibility it could work, but I'd bet that the efficiency loss would drive the size of the motors required to maintain level flight quite high, much higher than a direct drive quadrotor of equivalent thrust would ever be.
  4. Jul 1, 2012 #3


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    Gold Member

    There are lots of precedents for this idea in aviation.
    Few have actually performed in practice.
    The most extreme was the XV12, a VTOL fighter whose engine exhaust went through a nozzle that was supposed to entrain additional ambient air to increase the thrust in hover.
    Sucking in a massive amount of air to feed 4 cold gas jets is essentially what is proposed here. That will work, but the weight of the ducting needed will ensure that the performance of the vehicle will fall far short of any more conventional design.
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