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Re: [AWES] Re: FlipWing types?

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  • dave santos
    Joe, There are three main types of flipwing to my mind- tacking, shunting, and somersaulting. Shunting wings do not flip, but are so closely related in
    Message 1 of 6 , Jan 4, 2013
      Joe,

      There are three main types of "flipwing" to my mind- tacking, shunting, and somersaulting. Shunting wings do not flip, but are so closely related in design and operation to the others, that they form a natural set. Note that FlipWing (TM) was released for generic "flipwing" usage. Joe is welcome to formally classify these types, with perhaps some new parent term to reflect that not all "flip", and the stable ribbon arch is a key static case. The "types" may turn out to be "modes", since a single wing could perform several modes.

      Saunders' 1902 kite is revealed to be the direct ancestor of the amazing Caribbean three-stick kites made today. In our circle, Shawn Thomas is a Master of this type. Besides the optimized hummer, its a high-wind specialist, especially by the Y-bridled tails and elongated planform not seen in the patent.

      Following the patent time-machine yet farther back brings us to Maddeus's 1871 original hummer kite (patent 121056). Hummers are quite ancient in SE Asia, with many secrets to discover, but here is the modern historical lineage to our new flipwings. Despite the weird fact that modern NYC can hardly support a single kite shop, it has a formidable tradition going in these three-stick kites (all three references above).

      For a time, we feared Frayne claimed his WindBelt (TM) patent to be blocking on all forms of "hummer" energy extraction, until we noted Payne claimed the idea for large scale energy far earlier (no one developed it). The Frayne patent only covers use of a linear electrical generator on a ribbon-wing. Its obvious now that large scale versions will not be economic, by not directly supporting fast "generator speed".

      An urgent mystery about AWES flipwings has been solved- Would these wings still self-oscillate at the .1-1 km megascale? The answer is Yes, since we see the increasing suspended wing mass progressively acting as a quality spring-mass harmonic resonator (by outscaling windfield noise). The spring-mass determines itself as the primary Lyapunov orbit at larger scales. 

      By contrast, the small flipwings lacked enough mass to steady out, often sticking and "backfiring", such that limber tails served as regulators. The vertical tails proved a dead end at larger scales, defeated by increased mass causing two chaotic attractor modes- stability and "flop-over", as KiteLab Ilwaco eventually worked out. 

      Flip wings underwater may retain the flapping tail into larger scales, since the water is the massive actor. It remains a question how much von Karman wave formation helps to regulate flip-wings at higher Re, avoiding the use of added dynamic ballast mass.

      Its "official", the latest flipwings are TRL-9; ready for performance testing alongside all other AWES WECS. They seem to offer tremendous scalability and unbeatable power-to-weight. Expect many new demos of the latest wings driving all sorts of work cells,

      daveS

    • snapscan_snapscan
      Dave, How about a ram air kite with two intakes? Intake A gives the kite a profile with a positive angle of attack and exposes intake B. Intake B flips the
      Message 2 of 6 , Jan 4, 2013
        Dave,

        How about a ram air kite with two intakes? Intake A gives the kite a profile with a positive angle of attack and exposes intake B. Intake B "flips" the profile to a negative angle and exposes intake A.

        Flipping between two aerodynamic profiles/angles of attack should vastly increase the efficiency of the wing.

        What do you think?

        /cb

        --- In AirborneWindEnergy@yahoogroups.com, dave santos wrote:
        >
        > Joe,
        >
        > There are three main types of "flipwing" to my mind- tacking, shunting, and somersaulting. Shunting wings do not flip, but are so closely related in design and operation to the others, that they form a natural set. Note that FlipWing (TM) was released for generic "flipwing" usage. Joe is welcome to formally classify these types, with perhaps some new parent term to reflect that not all "flip", and the stable ribbon arch is a key static case. The "types" may turn out to be "modes", since a single wing could perform several modes.
        >
        >
        > Saunders' 1902 kite is revealed to be the direct ancestor of the amazing Caribbean three-stick kites made today. In our circle, Shawn Thomas is a Master of this type. Besides the optimized hummer, its a high-wind specialist, especially by the Y-bridled tails and elongated planform not seen in the patent.
        >
        > Following the patent time-machine yet farther back brings us to Maddeus's 1871 original hummer kite (patent 121056). Hummers are quite ancient in SE Asia, with many secrets to discover, but here is the modern historical lineage to our new flipwings. Despite the weird fact that modern NYC can hardly support a single kite shop, it has a formidable tradition going in these three-stick kites (all three references above).
        >
        > For a time, we feared Frayne claimed his WindBelt (TM) patent to be blocking on all forms of "hummer" energy extraction, until we noted Payne claimed the idea for large scale energy far earlier (no one developed it). The Frayne patent only covers use of a linear electrical generator on a ribbon-wing. Its obvious now that large scale versions will not be economic, by not directly supporting fast "generator speed".
        >
        > An urgent mystery about AWES flipwings has been solved- Would these wings still self-oscillate at the .1-1 km megascale? The answer is Yes, since we see the increasing suspended wing mass progressively acting as a quality spring-mass harmonic resonator (by outscaling windfield noise). The spring-mass determines itself as the primary Lyapunov orbit at larger scales. 
        >
        > By contrast, the small flipwings lacked enough mass to steady out, often sticking and "backfiring", such that limber tails served as regulators. The vertical tails proved a dead end at larger scales, defeated by increased mass causing two chaotic attractor modes- stability and "flop-over", as KiteLab Ilwaco eventually worked out. 
        >
        > Flip wings underwater may retain the flapping tail into larger scales, since the water is the massive actor. It remains a question how much von Karman wave formation helps to regulate flip-wings at higher Re, avoiding the use of added dynamic ballast mass.
        >
        > Its "official", the latest flipwings are TRL-9; ready for performance testing alongside all other AWES WECS. They seem to offer tremendous scalability and unbeatable power-to-weight. Expect many new demos of the latest wings driving all sorts of work cells,
        >
        > daveS
        >
      • dave santos
        cb, Current flipwings already closely maintain proper AoA, as cheaper simpler single-skin wings. The LE turbulators, TE eddy flaps, and tuned loadpaths all
        Message 3 of 6 , Jan 4, 2013
          cb,

          Current flipwings already closely maintain proper AoA, as cheaper simpler single-skin wings. The LE turbulators, TE eddy flaps, and tuned loadpaths all help. One sees wing camber reversing with each tack into the intended curve.

          Your idea is still a very good one, to have an aerostructure adapt by ram-air from various angles, but its a matter of finding the best places to use it (like isodirectional arrays). We have discussed this general sort of method before, but never developed it, its a wide-open area. Valved (flap-seals) ram-air cells are of particular interest to resist collapses when ram-air is interrupted. There is a whole world of "fluidic logic" to explore with large soft-kites.

          Our rule is "test, test, test...." so a simple working version made from scraps is better than any prediction. If you make even the crudest oscillator along the lines you envision, that's a cool experiment,

          daveS



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