Human-powered hull design

Discussion in 'Boat Design' started by CBTerry, Jan 6, 2019.

  1. rwatson
    Joined: Aug 2007
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    rwatson Senior Member

    What do you mean by "how to come up with stations"

    Until you have the hull form, dimensions, etc, you don't worry about the stations.

    You will have to get the hull form defined and finalised, then you worry about the stations to start building the hull.

    You have a lot of design decisions that you can't share here. Just Google Youtube for hull designs. Canoe principals appear to be a good start.
    Maybe you should have a look at online tutorials like
     
  2. CBTerry
    Joined: Jun 2017
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    Location: cocoa beach, planet earth

    CBTerry Junior Member

    Thank you for the video. I am familiar with the terms discussed in it. As mentioned previously form stability is not relevant since it will employ an outrigger
    . I guess I was thinking there was an equation, something like a NACA profile equation which would, given maximum beam, displacement and length, generate 1/2 circle stations to give a given Prismatic coefficient. I think I will probably be best served by eyeballing this and making it up as I go. It is going to be very long and skinny anyway so with little need for rocker, since it is a voyaging craft and maneuverability is not very relevant, making a tapered long skinny Hull shouldn't be too difficult. When I get the first one in the water I will be certain to post photos of it and the building process
     
  3. CBTerry
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    CBTerry Junior Member


    I will definitely report back and I am definitely going to have fun! Thank you!
     
  4. DCockey
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    DCockey Senior Member

    No formula as described exists "on the shelf". It could be derived.
    Semi-circular cross-sections below the waterline mean the "keel" profile will be the same as one-half of the waterline shape, rotated 90 degrees. If you want a straighter keel then the cross-section shapes will need to vary along the length.
     
  5. CBTerry
    Joined: Jun 2017
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    CBTerry Junior Member

    Yes, going from a center section that is one half of a circle tapering to something that looks more like the letter U
     
  6. tspeer
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    tspeer Senior Member

    Take a look at this thread. Leo Lazauskas and Ernie Tuck addressed the design of displacement hulls with minimum drag in this paper.
     

  7. Squidly-Diddly
    Joined: Sep 2007
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    Squidly-Diddly Senior Member

    besides semi-circle for least wetted area, I'm guessing you also want vertical sides at waterline, so waves just go up and down without lots of energy draining slashing.

    research "Fish form VS Swede form". IIRC Fish form (for surface) is better for rougher water, and Swede form is fastest most modern displacement hull where seaworthiness not a big factor (although you see most kayaks with Swede hulls, and they are certainly meant to push limits of seaworthiness for a given size).
     
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