transom edge sharp or not

Discussion in 'Hydrodynamics and Aerodynamics' started by fallguy, Jul 9, 2018.

  1. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Does the transom edge need to be sharp on my boat?

    I calculate a Froude number of about 0.9, based on a 9m/s velocity and a 10 meter long hull. If the calculation is bad, forgive me, I can redo it.

    Someone told me the boat would go 2-3 mph faster with a sharp edge.
     
  2. HJS
    Joined: Nov 2008
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    Location: 59 45 51 N 019 02 15 E

    HJS Member

    This is almost full planing speed, so the transom must be as sharp as possible.
    JS
     
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  3. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    "Sharp" needs to be defined, but losing 2-3 mph would require some kind of crazy radius.
     
  4. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    BFBAA246-C28D-4AC5-9842-C98015AAD297.jpeg How's this? Sorry bout the rotation.
     
  5. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Nothing to worry about, I'd say.
     
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  6. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    Mr E. is right.

    That radius will not cost you 2 to 3 MPH. If you make it into a sharp edge the corner will become vulnerable to chipping and breaking which may cost more speed that you might have gained
     
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