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Magneto-Hydro-Dynamis Propulsion

  1. Nov 25, 2004 #1
    This is my first post on this forum, but i have browsed through this website a bit and found it very interesting so i thought i'd post a new thread... so here goes:

    Can someone please explain how MHD Propulsion works. I saw a little bit of a show about this on the Science channel recently but was unable to grasp it completely.
  2. jcsd
  3. Nov 25, 2004 #2


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    MHD propulsion works by applying an EM force to a conductive working fluid, like sea-water.


    In a square channel two opposite faces employ two conductors with the a potential difference applied. This induces a current (I) flowing through the working fluid. On the other two faces a magnetic field (of strength B) is applied.

    The propulsive force is proportional to IxB, by virtue of the Lorentz force, F = q(v x B) or written another way, F is proprotional to I X B.

    I am not sure if you are asking specifically for this example, but there are other propulsion systems, e.g. magnetoplasmadynamic (MPD), using a similar principle but in the form of coaxial electrodes.

    In this case, the current flows radially, and making use of self-inductance, the I x B forces propels the plasma axially.
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