Everything Old is new again - Flettner Rotor Ship is launched

Discussion in 'Boat Design' started by rwatson, Sep 1, 2008.

  1. Dolfiman
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    Dolfiman Senior Member

  2. Clarkey
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    Clarkey Senior Member

  3. rwatson
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    rwatson Senior Member

    Good point Clarkey. I think a big reason Rotors get ignored is that they can be ugly. The designers are doing their best to overcome that. Mind you, the Cinema Pathe historical videos of the old Buckau , silently cruising along under rotor power with apparent effortlessness are quite inspiring.
     
  4. Clarkey
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    Clarkey Senior Member

    One thing that strikes me when I see film of Buckau and video of E-Ship 1 is that they really move like sailing vessels - a slight heel and and a motion that shows they are truly interacting with two elements rather than just one. There was an interesting comment in the E-Ship presentation about the motion being affected (in a positive way) by wind and gyroscopic forces on the rotors.
     
  5. Dolfiman
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    Dolfiman Senior Member

  6. 1J1
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    1J1 Senior Member

    Not a good ship arrangement. They achieved a slim streamlined hull, but the vessel doesn't look efficient enough in terms of cargo capacity & those rotors will be restricting cargo handling operations.
     
  7. rwatson
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    rwatson Senior Member

    Nah - they have no trouble overhead lifting containers from next to other vertical containers, and other regular ship superstructure. I can't think of many commercial unloading ports that use swing cranes anymore.
     
  8. 1J1
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    1J1 Senior Member

    You're talking about handling containers by big gantry container cranes - you're right then, but these cranes are mostly in ports that can accept big container ships. The proposed vessel is a short-sea multipurpose vessel which will carry various stuff from containers to windturbines' parts & is likely to sail all around Europe & there are a lot of ports that have just swing cranes or harbour mobile cranes (like by Liebherr or Gotwald) or just truck cranes which do all the cargo handling. Here's how containers are handled in my hometown - http://www.shipspotting.com/photos/middle/1/2/1/1432121.jpg
    At least E-SHIP 1 has it's own 2x80t cranes.


    You missed this one then!

     
  9. rwatson
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    rwatson Senior Member

    Then I rest my case. That ship has superstructure as tall as a rotor, AND all those cranes are designed to lift the container straight back to the wharf. There is NO swinging involved, as you can see from the two cranes at opposite ends of the unload/load cycle.

    Container.jpg
     
  10. Dolfiman
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    Dolfiman Senior Member

  11. rwatson
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    rwatson Senior Member

    I came across an old Flettner project, so I will put the link here for future reference
    Spray vessel in dock.jpg


    MarplesFlettner
     

    Attached Files:

  12. rwatson
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    rwatson Senior Member

    Hi chaps. Its fun to consider adjustments of the Flettner concept.

    I remember discussing the "hybrid" variations of Flettner rotors earlies in the Thread.

    Just after I read both you posts, I had a flash of crazy inspiration.

    For the times that wind angle is not optimum, or that the ship is at dock, as Dolfiman said, could we have an expanding "split" Flettner Rotor to generate power ?

    FletnerExpand.png
     
  13. Dolfiman
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    Dolfiman Senior Member

    Dear Rawtson,

    Yes, it is the idea.

    You can see on the net that kind of savonius rotor made of 4 to 8 flaps which can be closed in case of too strong wind, and more sophisticated, of such flaps mounted with restoring springs so that their opening are automatically adjusted with wind force for an optimum efficiency in all conditions.
     
  14. thiseasm
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    thiseasm Junior Member

    Dear Dolfiman,
    could you provide us relative links?
     

  15. Dolfiman
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    Dolfiman Senior Member

    This link, in french but with a lot of sketches, inc. the Fig. 9 which clearly shows the principle from light to strong winds.
    http://www.onpeutlefaire.com/construire-une-eolienne-a-axe-vertical

    You should get that easily from the net. From Wiki for example :
    Vertical axis wind turbine - Wikipedia https://en.wikipedia.org/wiki/Vertical_axis_wind_turbine

    The Savonius type of VAWT (Vertical Axis Wind Turbine) is not the most efficient as the "scoop like" blades don't generate lift and so can go only as fast as the wind (unlike advanced VAWTs like Darrius rotor with their twisted blades that generate lift). So the relation here is simple : tangential speed = wind speed at the max
    Note that here in your non conventionnal case, this low efficiency is not a complete disadvantage : in rear winds conditions, the drag of the wind turbine resulting from this low efficiency can be used directly as thrust for the boat propulsion. So , it is a question of trade off between these 2 uses of the wind (boat propulsion, electricty production), only numerical simulations and experiences can orient you towards the best use.
     
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