Fn > 1: Displacement effects on performance and maneuvering?

Discussion in 'Powerboats' started by oldbitd, May 13, 2010.

  1. oldbitd
    Joined: May 2010
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    oldbitd New Member

    Assuming:

    1. Planing speeds
    2. Infinite power

    I am researching high speed vessels and maneuvering capabilities and I am looking for advice/previous research on how increasing displacement effects a planing hull. I am particularly interested in Beam/Disp^(1/3) effects on planing vessels, ie

    At constant Fn number, how does the same vessel with a high Beam Disp ratio perform relative to a vessel with a low Beam Disp Ratio?

    I assume higher trim, deeper draft, but any more specifics especially regarding steady turning. All help is greatly appreciated.
     
  2. Alik
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    Alik Senior Member

    These diagrams show effect of chine beam Bc on resistance R, for two displacements, for 10m powerboat.
     

    Attached Files:

  3. jehardiman
    Joined: Aug 2004
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    jehardiman Senior Member

    Get a copy of the Series 62 and Series 65 planing data (Most of it is condensed in Principles of Naval Architecture). FWIW, I really don't see how normalizing data on Beam/Disp^(1/3) will be of any use. With a constant displacement, varying the beam also requres a change in deadrise, length, or both; and those two factors will be of more influence than beam. Especially on maneuvering.
     
  4. oldbitd
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    oldbitd New Member

    Alik, can you tell me the source of this graph, it is useful. Cheers
     

  5. Alik
    Joined: Jul 2003
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    Alik Senior Member

    This is pre-design study for one of our designs. Calculation done by Savitsky method.
     
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