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
    Posts: 148
    Likes: 15, Points: 18
    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?
     
    dustman, May 10, 2022
    #1
  2. Will Gilmore
    Joined: Aug 2017
    Posts: 706
    Likes: 294, Points: 63
    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
    Will Gilmore, May 10, 2022
    #2
  3. jehardiman
    Joined: Aug 2004
    Posts: 3,214
    Likes: 669, Points: 113, Legacy Rep: 2040
    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.
     
    jehardiman, May 10, 2022
    #3
    DogCavalry likes this.

  5. AlanX
    Joined: Mar 2022
    Posts: 88
    Likes: 18, Points: 18
    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
     
    AlanX, May 11, 2022
    #4
    DogCavalry likes this.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.