New Age Trawler/Motorsailer; Kite assisted PowerYacht

Discussion in 'Boat Design' started by brian eiland, Nov 20, 2007.

  1. ingovoegler
    Joined: May 2011
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    Location: goa

    ingovoegler kite sailor

    Doug Lord,

    the nice location is where I have been living for the past five years, one of the few drawbacks is, that sufficient wind for (at least kite-)sailing is very rare here. The foil provides mainly lateral resistance, the downforce is negligible, would have to place it at a different angle, but a certain lift from the kite is well appreciated, as it makes the boat lighter and by sitting more towards the bow I counter it enough, to prevent problems. As you seem to be enthusiastic about foils, as well as kiteboats, you will certainly be very interested in the kiteboat project of Don Montague, who has among other hull configurations with foils, reanimated a bigger version of the hobie trifoiler. In case you didn't know it already here is the linkhttp://project.kiteboat.com/

    Ingo
     
  2. ingovoegler
    Joined: May 2011
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    ingovoegler kite sailor


    Boston,

    thanks for compliments, my (written) English is fine due to the use of a dictionary, spoken it would be a different story. I have further simplified my invention, second (http://www.youtube.com/watch?v=_JmrCF-8YBU) and third (http://www.youtube.com/watch?v=yVwZRZYkzzE) prototype have been quite easy and fast to build, and due to heavily reduced weight are performing much better.
    If anyone, be it Skysails, Don Montague (http://project.kiteboat.com/) or anybody else, solved the launching(not that big of a problem in my opinion) and recovery(!!) problem in a way, that would allow comfortable use in smaller and medium sized yachts at an affordable price, I would bet any money that kiteboats would soon replace conventional sailboats, offering the opportunity to use much bigger sail area on completely heeling free and capsize-safe boats. I am, however, not so sure that it is going to happen soon.

    Ingo
     
  3. sigurd
    Joined: Jun 2004
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    sigurd Pompuous Pangolin

    not stopped, at all, but apparently I am too lazy to get anything done. I've broken all daggerboards I have used, so I need to get me a proper carbon one. The tornado (20ft cat) was too heavy for upwind work with my kites, I am going to experiment with dual kites until I can afford a 21m flysurfer speed. Right this morning I have started patching up a kayak that was sawed in two, it is going to be a proa (goes backwards and forwards instead of on starboard/port tack) with the daggerboard in an outrigger float.

    I have found that a meter or so difference in kiteline length is ok, when they are out they get to the same length. I had the rear lines running through a pair of lightweight pulleys (took me a while to find pulleys that would not seize on the thin kitelines, and q-power-lines help too), which in turn are attached to the control bar on adjustible length (0-0.5m with a prussik knot) ropes. When the lines were out I just bypassed the pulleys by hooking the rear lines directly to the bar.

    I had a great time getting thrown out of the Europe dinghy, holding onto some rope and the control bar, trying to keep the kite flying while crawling back inside what was now a bathtub. One of the funny things with kitesailing is planing from zero knots and up :) .

    I am attaching a sketch of the attachment system that I'll try on the proa kajak, which solves for pitch and yaw to some extent.
    And a sketch of my kite reel - I forgot to draw the ring (padeye) that guides the lines onto the spool but you'll have to imagine it.
     

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  4. sigurd
    Joined: Jun 2004
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    sigurd Pompuous Pangolin

    And on the subject of non-heeling kite systems, Peter Lynn has invented a neat system that aligns the kite pull with the center of lateral resistance of a fixed daggerboard. He used it on a long skinny monohull. IIRC the daggerboard was later replaced with two through hull rudders. It is documented somewhere in his online newsletter I think.

    I have attached a sketch of the principle - hope it can be understood.
     

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  5. sigurd
    Joined: Jun 2004
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    sigurd Pompuous Pangolin

    For safety release, all my kites needs to be held in one line only in order to depower. What I did is to stop one of the lines by attaching a steel ring at its end, which would not be able to pass through the line guide ring (padeye). The drawing only shows the front lines, for clarity.
    The orange rope is 10m longer than the blue one. So if I need full depower I can let out the orange while the blue is held. Always keep a knife handy - once I caught a motor boat with my kite. It was too little wind to keep it flying.

    PS: Launching issues depend a bit on the wind and type of kite. If there is little wind it can be good to launch a dry kite, otherwise I just inflate it somewhat and let it drift to leeward. As my boat was so light I used a sea anchor to let the kite drift faster than me. I could do this without a reel too. For dry launching I used a few different pole systems to hoist the kite, let it inflate and fly while I reeled out. One of them was the stock Europe dinghy mast, worked ok but it was in the wrong place so gybing got more complicated. I made an attachment in the middle of the leading edge of the kite to hoist. Then I used two telescopic fishing poles mounted like a V on the stern, with the kite spanning between them. Worked ok but one of them broke. So lastly I used just one telescoping pole on the stern and it worked ok too. With a motor, light wind launching should be much easier. Otherwise, I imagine hoisting the kite like a spinnaker to gain apparent wind will help.

    Edit: here is a neat launch system too, for different application: http://www.youtube.com/watch?v=jHeSKFW5xuY&NR=1

    edit: very messy pic of the reel: http://www.boatdesign.net/forums/attachments/sailboats/7672d1150779259-kite-dinghy-cimg1866.jpg
     

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  6. brian eiland
    Joined: Jun 2002
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    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    Energy-generating Kite Aces LabVIEW tests

    Control unit for energy-generating kite aces LabVIEW tests

    KITEnergy is a revolutionary technology that converts higher-altitude wind energy (between 200 and 1,000 m above the ground), with respect to the actual wind turbines, into electricity. High-altitude winds are stronger and more constant. Because the generated power grows with the cube of wind speed, it can achieve a significant increase of power production.

    To exploit high-altitude wind, KITEnergy uses wings (or power kites) linked to the ground by two cables. The flight of the wings is tracked using onboard wireless instrumentation driven by an automatic control unit that can differentially pull the lines to influence the wing motion. Electricity is generated at ground level by converting the traction forces acting on the lines into electrical power, using suitable rotating mechanisms and electric generators. Recent studies – including theoretical analyses, numerical simulations, and experimental tests – carried out at the Politecnico di Torino, indicate that KITEnergy technology can produce large amounts of renewable energy that is available practically everywhere in the world at a lower cost than fossil fuels; thus, it does not require public incentives for its diffusion, a difference from the available renewable energy technologies.

    ....more here:
    http://www.designfax.net/enews/20110802/feature1.php
     
  7. Boston

    Boston Previous Member

    Hey Ingo

    what if you only launched and recovered the kite off the mast and had a system that held the moment arm much lower on the boat, reducing heel. Say a track that ran around the deck and the lead line could attack there instead of so far off the deck, you might be able to reduce slip and heel some and get way better performance

    just an idea

    cheers
    B
     
  8. ingovoegler
    Joined: May 2011
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    Location: goa

    ingovoegler kite sailor

    Hey Boston,

    there isn't any heel in my system, as the foils and the moment arms are pivotable around a longitudinal axis, they are balancing out in front of the boat, only the driving and lifting forces, which both are appreciated are transmitted to the boat. frontview-ruder.jpg As the foils are asymmetric, they are highly effective(they seem to be to me at least), and I am absolutely satisfied with the performance, at least of my latest prototypes, the first one was just to heavy.

    In the first prototype I actually had chosen to keep the moment arms quiet long, because I had thought of launching the kite from them; however launching prove to be quiet easy, as long as wind was strong enough(~8knts), by just prefilling the kite on deck (I am using a foil kite, prefilling by holding it in the wind) IMG_1324.jpg and letting it drift away from the boat, then it easily would launch, whenever I want it to do so(by shortening the front lines). Even recovering the (21sqm-) Kite is manageable, however I couldn't launch it again until I took it to shore, untangled the bridle, dried and folded the kite in a predefined way (takes, on my terrace, around 10 to 15minutes for untangling and folding plus 30 to 45min, in Goan sun, for drying).
    This procedure, though it is perfectly acceptable for myself on my small dinghy, wouldn't be practicable on bigger boats/yachts and with bigger kites, and as I feel unable to solve this problem by myself, I can only hope for others to do so.

    Ingo
     
  9. ingovoegler
    Joined: May 2011
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    ingovoegler kite sailor

    Hey Sigurd,

    there shouldn't be any yaw in your proa, it should even steer itself, without a rudder, as the kite attachment point is far enough from the dagger board. Kite pull and resisting force of the dagger board will always aim to keep in the same line and thus keep the boat on track(on a fixed angle towards the kite pull), so you can steer by only depowering(for sailing upwind)/powering/sinussing/figure-eighting(broad reach) the kite.
    By moving the kite attachment point along the hull, the Angle of Attack of hull + dagger board will change. Proa will stop(resp. drift slowly sideways), when attachment point is in the center/vertical on dagger board and will accelerate, when moving attachment point towards bow/stern.
    I am wondering if you where using the same effect on the Europe dinghy or if you where using a rudder on that(with foot steering or helmsman?).

    About my reel: As also mentioned somewhere by Peter Lynn, line drag is heavily reducing upwind performance, so it is beneficial, to keep lines short while sailing close to the wind, but on other courses long lines are giving better performance, that's why I tried to have consistent line lengths for all four lines when fully rolled out as well when short. When the frontlines where of considerable different length, the kite would perform well only on one side, after jibing I couldn't go to windward anymore.
    Now however after having skipped the reel and just using the original kitesurfing bar with 21m lines, I am quite okay with the upwind performance.

    For starting the kite in light winds, as you did, I used a drift anchor, when the wind was to light for the wet kite to easily start, I usually couldn't keep it in the air for long anyway.

    Ingo
     
  10. sigurd
    Joined: Jun 2004
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    sigurd Pompuous Pangolin

    I used rudder with foot strap on tiller.
     
  11. sabahcat
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    sabahcat Senior Member

  12. brian eiland
    Joined: Jun 2002
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    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

  13. Boston

    Boston Previous Member

    hey thats really slick Brian

    Two thumbs up
     
  14. 4wings
    Joined: Jan 2012
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    4wings Junior Member

    yup they actually solved the problem this thread is discussing for the last 5 years ...
     

  15. brian eiland
    Joined: Jun 2002
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    brian eiland Senior Member

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