SWATH speed and stability opinions

Discussion in 'Boat Design' started by jon haig, Jul 25, 2019.

  1. BlueBell
    Joined: May 2017
    Posts: 2,750
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    Location: Victoria BC Canada

    BlueBell . . . _ _ _ . . . _ _ _

    John,
    I believe the correct term for what you are attempting to describe is transfer.
    If you're going to be a know-it-all, it's important to be correct, otherwise...
    well, it just looks bad.
     
  2. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    ??? We were not talking about the actual geometry of the turn (i.e. the advance, transfer, and tactical diameter) but rather the orientation of the ship to its course over ground. Yellowjacket used the aerodynamic term "slip" Slip (aerodynamics) - Wikipedia https://en.wikipedia.org/wiki/Slip_(aerodynamics) for the orientation of the hull to the track while in a turn. A ship does not "slip", it "skids" Skid (aerodynamics) - Wikipedia https://en.wikipedia.org/wiki/Skid_(aerodynamics) because the rudder is always outside the CG during the turn for SWATHs and all other vessels except fully flying hydrofoils.
     
  3. darionauticaitalia
    Joined: Nov 2022
    Posts: 1
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    Location: italia

    darionauticaitalia New Member

    good evening
    I have tried to build various scale models to be able to produce pleasure swaths in the future, but despite the efforts in designing and building, and testing in the tank, the stability of this boat is precarious, I have not succeeded
     
  4. BlueBell
    Joined: May 2017
    Posts: 2,750
    Likes: 997, Points: 113
    Location: Victoria BC Canada

    BlueBell . . . _ _ _ . . . _ _ _

    Good evening darionautica,

    I strongly suggest you start a new thread with some pictures and a SOR, what it is you want out of these "pleasure swaths" you speak of.

    Welcome to the Forum

    (Sadly, you may have to wait a day or two before you can load pictures or even start a new thread...)
     

  5. Ad Hoc
    Joined: Oct 2008
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    Location: Japan

    Ad Hoc Naval Architect

    Welcome to the forum D.

    Are you just testing a model and seeing what works,
    or
    Are you testing a model based upon a design you have?

    It sounds like you have a simple KG issue...and hence the restoring force is insufficient for the hull form, hence the stability issues.
    That's why i ask the question above.
     
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