Collapsible Flettner Rotor Project

Discussion in 'Projects & Proposals' started by Yobarnacle, Jun 4, 2014.

  1. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member holding true course

  2. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Soooo - hows it all going then ???
     
  3. Sailor Alan
    Joined: Mar 2014
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    Location: Gig Harbor WA

    Sailor Alan Senior Member

    Glad to see this still progressing. See above, do you mean 'beam' or 'length'?

    I would go with two rotors, spaced as far apart as practical. Near field interferance will be an issue if they are closer than 2 diameters. Offset might be fine, consider having them on diagioally opposite quarters might be better.

    The 3' or 1m diameter diameter is excellent and practical. I would go with 15' to 20' or so total rotor height as being practical as well. I still seriously favor the theater lighting truss beam, rigged vertically, and with builders foam ribs, covered with Tyvek film. This could be made perminant, or reefing, to choice.

    Forget the catapillar drive. We helped spend millions trying to get this to work and the thrust, though measurable, was insufficient to overcome magnet installation, let alone power generation.

    Some of the other options sound good, though the rotors generating power at anchor, and driving the boat with no wind sound really excellent.
     
    Yobarnacle and Kai Rabenstein like this.
  4. Kai Rabenstein
    Joined: Jan 2019
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    Location: Hastings, UK

    Kai Rabenstein Junior Member

    Came across this thread belatedly after working on a very similar idea for the past 2 months (see image) - would love an update on what became of the proposed installation! Must say I am impressed by YB's enterprising and independent mindset and also by daiquiri's lucid, entertaining and well-read comments as well as SA's and rwatson's persistent encouragement of what might otherwise seem a rather whacky notion.

    Flettner's original pioneering work clearly demonstrated the potential of his concept, but repeated external factors (improving diesel engines and falling fuel prices) have repeatedly doomed efforts to bring about its wider commercial adoption - this seems set to change since about 2014 with the end of the fossil fuel era slowly hoving into view. However the adoption of the Flettner rotor sail by the leisure marine industry has also failed to date - and interestingly here the 'ugliness factor' has been held to have been the main reason for this among sailing enthusiast. Cousteau's partially similar TurboSail concept installed on his 'Alcyone' has for decades now been the only serious attempt to nudge the sub-commercial boating world towards accepting new wind assist propulsive devices, but even that has not found favour beyond his own organisation. With the arrival of multiple new technologies and materials a tipping point in this regard may now be at hand when the use of the Flettner rotor can be extended to incorporate additional functionality useful precisely at times when its propulsive Magnus effect is minimised or negated - i.e. with a head or following wind direction and at anchor.

    My envisaged installation would, in full scale (on a 10m/34ft catamaran), probably be based on a commercial Finnish Windside twisted Savonius turbine of dimensions 1.05 x 4 m (or at least its generator/motor base) if I can persuade the company to sponsor my research. At the same time I am also planning to install a similar but much smaller column on a 9ft dinghy tender, again hopefully Windside's commercial 0.34 x 2.06 m model. My plan is to pivot vertical slats of ⅓ rotor circumference around their midpoint anchorage as shown to convert the Flettner rotor into a Savonius turbine, assuming a single axial driving shaft. Alternatively, covering the Windside's twisted Savonius turbine with a reefable mesh surround may be worth investigating. A further intellectual starting point has been to cover the outer Flettner/Savonius column surface with fully flexible thin-film solar panels which are just now beginning to become commercially available, in order to significantly increase the solar estate on the boat beyond what's available on the cabin roof.

    Like YB I would warmly welcome insightful comments on this variant on the same theme.
     

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  5. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member holding true course

    I've been incommunicado for several years. I'm pleased to see continuing interest in this thread. thank you everyone for your posts
     
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  6. Frank corning
    Joined: May 2020
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    Location: Fergus ON

    Frank corning New Member

    I have a Hudson t7 rowing shell. The footboard or stretcher is aluminum but after 15 years it has come off.
    I want to know how to glue it back to the floor of the boat. It will not get very wet but there is some stress when I drive off the stroke ( not too much drive in these old legs). The boat is supposed to be made of something called plastimet. Once I used some acetone on it ...not a good idea it degraded the shell.
    Any recommendations. I want to row soon and get this covid doldrums gone.
     
  7. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Any idea of what the original adhesive is? There are numerous modern products available. 3M 5200 is so stout once cured, it would outlive the components glued together. If you expect to ever need to remove the stretcher, use something less permanent than 5200.
     
  8. hoytedow
    Joined: Sep 2009
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    hoytedow Wood Butcher

    3M 5200 is a great product, as a sealing bedding compound, with great durability, but for adhesion I prefer epoxy for it is far stronger.
     
  9. Yobarnacle
    Joined: Nov 2011
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    Location: Mexico, Florida

    Yobarnacle Senior Member holding true course

    3M 5200 is an excellent adhesive much more tenacious than liquid nails. Is used for gluing on patches on dacron sails. Won't come loose in a hurricane, if you were imprudent enough to hoist a sail in a hurricane.
    takes two days to set up fully.
     
  10. hoytedow
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    hoytedow Wood Butcher

    For large areas above water line I generally use Loctite concrete patch as a cheaper alternative. It isn't white but it is similar and very tough.
     

  11. Yobarnacle
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    Yobarnacle Senior Member holding true course

    3M 4200 is less tenacious and less expensive. I have used it above the waterline.
     
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