Question about stability(newbie)

Discussion in 'Stability' started by turbo2, Aug 16, 2008.

  1. turbo2
    Joined: Aug 2008
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Los Angeles

    turbo2 New Member

    Bare with me guys, I am new to this. Alright, so I recently began reading about boat stability and have come across several products that help do so, namely gyroscopes. I am slowly understanding how they work; a change in angular momentum of the flywheel creates a torque which is coupled back into the ship to reduce roll moment.

    I have a question though, would it be possible to stabilize a boat with JUST a spinning flywheel and no gimballing? I know that a fast spinning wheel will resist any change in its motion due to inertia. Can this concept be applied to this situation??
     
  2. rwatson
    Joined: Aug 2007
    Posts: 5,866
    Likes: 299, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    Great idea turbo. Theoretically, the gyroscope would keep the boat perfectly level in waves, and in small waves this might work .

    The trouble could come when bigger waves *have* to move the boat. A big wave could overcome the original horizontal axis, and then you would have a boat being kept at a 25 degree angle by the flywheel after the wave had passed.

    Also, Flywheels exert their effort in full 360 degrees around them, so it would also be fighting the pitching motion of the boat, as well as the rolling motion. That would put incredible forces on the flywheel support structure when the boats bow was forced up by a wave, or the bow dived into a trough.

    I think though that the concept could work in calm waters with a little chop, and a specially designed hull. For example, maybe a houseboat could be made stable from those annoying small wakes caused by nearby powerboats

    Other dicussions have mentioned using a flywheel as a source of power storage - maybe the two effects could be utilised.

    I look forward to hearing other discussions on the concept.
     
  3. TeddyDiver
    Joined: Dec 2007
    Posts: 2,579
    Likes: 123, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

  4. rwatson
    Joined: Aug 2007
    Posts: 5,866
    Likes: 299, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    "Unlike hydrodynamic roll stabilising fins, the ship gyroscopic stabiliser can only produce a limited roll stabilising moment that may be exceeded as the wave height increases. Otherwise, it is not unusual for the manufacture to recommend that the unit not be used at sea in large waves."

    That was a good guess then :)
     
  5. turbo2
    Joined: Aug 2008
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Los Angeles

    turbo2 New Member

    so what will govern the stability of such a device? Since there is no gimballing-just a spinning flywheel and shaft fixed on supports, i am guessing there will be no output or "counter" torque.

    Great input though. Keep it coming. Thanks
     
  6. TeddyDiver
    Joined: Dec 2007
    Posts: 2,579
    Likes: 123, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

    Spinning wheel...
     

  7. Ike
    Joined: Apr 2006
    Posts: 2,476
    Likes: 338, Points: 83, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

Loading...
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.