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Aerospace Maglev for Re-entry

  1. Dec 4, 2008 #1

    LURCH

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    I was just wondering;

    What would happen if a Halbach array of magnets were placed just beneath the heat shield on a reentry vehicle? The plasma produced by reentry is, essentially, charged particles moving at high speed. Would a Halbach array magnetically levitate the reentry vehicle away the from the plasma (IOW, recall the plasma away from the heat shield) the way it does with an inductrack maglev?

    If so, would the increase in distance result in less heat being transferred to the vehicle, or with the work being done on the magnets caused them to heat up?
     
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  3. Dec 5, 2008 #2

    Danger

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    I can't believe that no-one has responded to this. It's a very interesting question. While I've never heard of a 'Halbach array', I'm going on the assumption that it's the layout used for a typical maglev system. I'll look that up later.
    I would suspect to start with that such an array would have to be above the heat shield rather than below it, to prevent it from melting. (Or did you mean 'beneath' as being in a deeper layer?)
    If they're electromagnets rather than the permanent variety, they'd definitely heat up due to electrical resistance, but not to the temperature of the plasma sheath. The components would melt before that happened.
    This is way beyond me, though, so I hope that someone else chirps up. I'm most interested to see what the consensus is.
     
  4. Dec 5, 2008 #3

    LURCH

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    The Halbach array is indeed a configuration of permanent magnets that generate lift as a result of a charged mass moving past (for use in a particular type of maglev called an inductrak).

    (I should have put those links in the OP.)

    I've also tried discussing the potential for this type of maglev for roller coasters (although I guess we'd have to just call it a "coaster," without the "roller"). But it's very difficult to introduce such a new idea to anyone who might be able to do something about it.
     
  5. Dec 6, 2008 #4

    Danger

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    While I muchly appreciate the link that you provided, I must readily admit that it is far beyond my understanding.
    That having been said, I've never shied away from offering an uninformed opinion. :biggrin:
    Skipping off of the plasma sheath sounds good to me in principle, as long as that sheath doesn't just shred the artificial magnetic field. It sort of seems like trying to surf a tsunami.
     
  6. Feb 10, 2011 #5
    Wouldn't your array attract the charged particles as often as repel them, with no net effect?
     
  7. Feb 14, 2011 #6

    LURCH

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    I don't think that it would. A Halbach Array repels ordinary rails in an inductrack maglev. Of course, in that case, the rails are neutral whereas plasma is charged.

    Perhaps just a set of permanent magnets with the positive pol facing outward?
     
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