Almost ready to build test boat - Methodology for design

Discussion in 'Hydrodynamics and Aerodynamics' started by dustman, May 10, 2022.

  1. dustman
    Joined: Jun 2019
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    Location: Tucson, AZ

    dustman Senior Member

    I am close to being ready to start building a very small catamaran for testing on lakes.

    What is the methodology for figuring out the most efficient hull configuration for best efficiency at a given design speed and displacement?

    How do you scale from a small prototype to a larger vessel? What needs to be taken into consideration when scaling?
     
  2. Will Gilmore
    Joined: Aug 2017
    Posts: 706
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    Location: Littleton, nh

    Will Gilmore Senior Member

    This is a very intelligent question, because scale can be very interesting and complicated for sailing.

    Winds, waves, viscosity of both water and air don't scale with the model. A light, five knot breeze to a full size boat can be like twenty knots over the water to a scaled model. This effects ballast and sail area.

    I only have a minimum experience with experimentation of these concepts, so I would suggest keep asking these questions and do a lot of your own thinking about what is different for a model than for the vessel that is four to a hundred times bigger.

    Common sense and experimentation will likely give you the best answers. Those need not necessarily be your own.
     
    Last edited: May 11, 2022
  3. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    What size is "very small"? Most "model" testing requires very accurate (not necessarily precise except as precision relates to the value) measurements; which for most people rules out quantitative analysis for qualitative ones.
     
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  4. AlanX
    Joined: Mar 2022
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    Location: Perth, Western Australia

    AlanX Senior Member

    If you just want to design a sailing catamaran, assuming that is the type of catamaran you require.
    Google for "HOW TO DIMENSION A SAILING CATAMARAN?".
    It will get you started.

    Regards AlanX
     
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