A cockpit between a foil and a kite

Discussion in 'Boat Design' started by Hacklebellyfin, Oct 6, 2008.

  1. Hacklebellyfin
    Joined: Oct 2008
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    Hacklebellyfin Junior Member

    hi in my megadream today,

    have you seen that:


    What would it take to have a ultra light cockpit on that string at around 30 from surface?

    ferro-cement foil with water ballast, pumps and inflatable raft while at rest.

    automatic winches when wind weakens under and upper the cockpit.

    Cockpit made of whatever very light but with a huge round window on nose/bow.

    a very big Kite.

    Hope i made you dream as i did.

    P.s. :Finally, I may need a Zeppelin :D
     
  2. eponodyne
    Joined: Aug 2007
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    eponodyne Senior Member

    You would need the entire world's supply of Dramamine, for starters.

    it looks to me like an entirely unnecessary and incredibly dangerous idea. Have a human dangling from a bit of string 30 meters above the cruel sea while unknown forces pull him through the sky?


    ARE YOU BARKING MAD???

    Oh, it might be a fun place to put a crying child, but not a REAL PERSON!!
     
  3. captiankeyboard
    Joined: Feb 2008
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    captiankeyboard Junior Member

    great idea huck

    i think the ride would be incredibly smooth, if you look at the white flag along the kite line during the sea trials towards the end of the video it hardly moves.

    i have been thinking of the same thing for a while, inspired by the exact same video.

    a problem is that the boat in the video only goes one way, it could shunt like a proa -by rotating the foil- but to do this the whole boat would have to come to a stand still and the pod would drop out of the sky - ouchhh. to rotate the foil at speed would be suicide, look at about the 4 minute mark in the video when the foil leaps out of the water. imagine being in the pod during that.

    so i think the overidding priority of the design is to keep the foil under the water at all times. if that cant be gaurenteed i cant see anybody wanting to be the test pilot.

    i am testing models at the moment to deal with the problem of steering. my idea is to have a single wing as the foil. the foil i choose is a proa foil that tom speers designed. so it develops lift in both directions so the kite boat becomes a proa. the foil under the water would be set up like a four line kite connected to the pod. not to steer the foil but to adjust the angle of attack.

    if each kite acts as the pivot point for the other kite, i think it creates the forward motion we see in the video? if anyone would care to expand on this?

    to steer the boat you just increase the angle of attack of a kite this creates drag holding one pivot point back as the other kite pivots further around it and changes the course, or vice versa as you decease angle of attack and decrease drag.

    shunting provides a chance to change direction while still keeping the lines tight and the pod in the air.

    initially i would leave the pod out and just get a man in a harness, a pod would hit the water to hard.

    any thoughts?
     
  4. captiankeyboard
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    captiankeyboard Junior Member

    i think i misunderstood ultralight cockpit as a cockpit made of ultralight materials, did you mean a sailplane?
     
  5. Hacklebellyfin
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    Hacklebellyfin Junior Member

    something a bit bigger with a bed and kitchen.
    Living bubble.
    kind of flying "teardrop trailer".
     
  6. keith66
    Joined: Sep 2007
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    keith66 Senior Member

    If you put the foil or hapa at the bottom of a long thin carbon fibre "keel" with the cockpit pod on top, at rest it would sit in the water like a rather deep keelboat, once kite borne the pod could fly just above the waves.
    Best have plenty of kevlar in the pod as carbon is rather sharp when you crash.
     
  7. tspeer
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    tspeer Senior Member

  8. yipster
    Joined: Oct 2002
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    yipster designer

    i imagined old so called otters as used for mine sweeping as rudders
    but a stearable kite may be even better and a live raft as flying cockpit
    how a kite was used to keep the otter down i'm still reading
     
  9. Tcubed
    Joined: Sep 2008
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    Tcubed Boat Designer

    This is another idea i dreamt of as a teenager....Too bad i had no money then to go and get some patents.!

    In my idea i had the fellow strapped into the kite, controlling the underwater foil from up there through the wires, and making sure he does not get unglued.

    I had already seen that video. What really impressed me was how they got the underwater foil auto stable. Ok, so it comes out at one point, but the fact that it reattaches is very impressive, and means it is very stable. I'd love to know what mechanism they use to keep it at a determined depth.

    In my idea i could not figure out a neat method, which did not use vulnerable surface sensors. So i got stuck at the 'athlete manually controls' stage. Would put kite sailors to shame i think.........

    As far as sticking a pod in between, it should work as soon as the auto stable issue is made 100% full proof, in all conditions, with full control maintained at all times for landing safely always, etc.

    I don't think shunting is the way, though, as this means that by definition the foil stalls, even for just a moment, which is very hard to control and would almost certainly lead to ungluing. The foil needs to be directional. To change movement through the axis of the wind, the foil is just looped downwind and onto the new course. (just like wearing ship) This ensures the foil is always moving and working. Since the foil is pretty small, it could be turned around in a tight radius, it would almost look like it just 'snapped' onto the new course.

    Someone said a lot of dramamine, someone else said the movement is smooth. The latter is correct. There could be no other maritime transport which is so completely independant of the troublesome sea surface, not even foilers. Although there's always the bump of the landing!
    Dramamine is not it, strong liquor maybe, to get the courage to test fly it.
     
  10. captiankeyboard
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    captiankeyboard Junior Member

    tcubed

    "To change movement through the axis of the wind, the foil is just looped downwind and onto the new course"

    i dont know what this means, could you please explain 'looped downwind' or maybe draw a picture.

    thanks for the input
     
  11. Tcubed
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    Tcubed Boat Designer

    Suppose you want to tack. You turn the foil away from the wind, until it is going downwind, you don't stop turning it, you keep turning so now the foil is pointing more and more into the wind until you've reached the correct course on the other tack. That is known as "wearing". Of course one must simultaneously readjust the kit so it is now pulling the other way for the new tack (or "board")
     

  12. YuriB
    Joined: May 2008
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    YuriB Junior Member

    To me, the system in subject is allways be a toy of the wind.
    However, here's another idea. Why not use it for glider to assist him to gain altitude... It drops floating anchor, rises like a kite, pulls the anchor out of water, glides down, than again, drops the anchor..
     
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