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Lifters ?

  1. Jan 26, 2008 #1
    I am interested in this Hobby.
    I have seen several experiments and it looks pretty easy to do.
    I am wondering what exactly lifts this?
    Is it Ions or ??
    They had done a test in a vacume chamber and it was still working, are ions present in a vacume?
    If it's not ions, then what makes the model rise? And I wonder how high it would rise if it did not need the power line connected?
    They say it's high voltage, low wattage 30k
    Anybody taking this seriously?
    I heard they are using this technology in the leading edges of the B1 Bomber to create more lift.
    Anybody?
     
  2. jcsd
  3. Jan 26, 2008 #2

    Hurkyl

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  4. Jan 28, 2008 #3

    Mech_Engineer

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    Ions created in the air from the high-voltage areas of the lifter provide a repulsive effect on one end and an attractive effect at the other that propels the model.

    http://en.wikipedia.org/wiki/Ionocraft

    EHD Lifters do NOT work in a vacuum, no matter what you think you have seen or heard on the internet. It is a myth propogated by anti-gravity nut jobs. No fluid surrounding the model means no thrust.

    Well that's a wierd thing to think. Where exactly did you hear that?
     
  5. Jan 28, 2008 #4

    Hurkyl

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    Clarification -- they do not work in a 'hard' vacuum. If the quality of the vacuum is sufficiently poor, enough fluid remains to allow them to work.
     
  6. Jan 28, 2008 #5

    Mech_Engineer

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    The point is they are NOT an anti-gravity device, they require a medium like air to create ions for thrust. Saying they work in some vacuums might be technically correct for a very poor vacuum (if you like measuring thrust in micro-newtons), but propogates the wrong idea. As it is, a relatively poor vacuum is really just a very low-pressure gas. Unfortunately in the real world, the distinction between gas and lack of it (vacuum) is an infinite gradient of gray.

    I think the really important thing to take away from "lifters do not work in a vacuum" is "lifters do not work in space."
     
    Last edited: Jan 28, 2008
  7. Jan 28, 2008 #6

    Hurkyl

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    I believe several demonstrations have been performed in (poor) vacuums, in which the lifter does work. I was being pedantic on this point because the layperson could easily get the wrong impression from the claim "lifters do not work in a vacuum", and then reject what the scientists say when they see one of these demonstrations.
     
  8. Jan 28, 2008 #7

    russ_watters

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    Great link - I'd been wondering if anyone did any real tests of one of these in a vacuum (there is a crackpot claiming he did). I wish they had more there, though.
     
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