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Re: [AWECS] Top Megascaling Principles (especially "stake-out")

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  • dave santos
    Darin,   The funny thing is that ideas at the real frontier don t have a lot of web content, its up to us to create it. The main reasons for early
    Message 1 of 3 , May 8, 2011
      The funny thing is that ideas at the real frontier don't have a lot of web content, its up to us to create it. The main reasons for early disclosure on this public forum (OSA- Open Source AWE) is to prevent blocking patent monopolies & promote RAD (Rapid AWE Dev).
      But there is a vast amount of foundational content behind this thread. Just comb the text for search terms. KiteShip Gomberg+kite Lynn+kite world-kite-museum. etc. The fancy words are mostly defined online or Wikipedia topics.
      KiteLab experiment media can lag months before posting online, but here is the link- 
      Hope this helps...

      From: Darin Selby <darin_selby@...>
      To: airbornewindenergy@yahoogroups.com
      Sent: Sunday, May 8, 2011 9:12 PM
      Subject: Re: [AWECS] Top Megascaling Principles (especially "stake-out")

      Do you have some links to look at?  Thanks.

      To: airbornewindenergy@yahoogroups.com
      From: santos137@...
      Date: Sun, 8 May 2011 14:03:36 -0700
      Subject: [AWECS] Top Megascaling Principles (especially "stake-out")


      Hello All,
      Here is the latest take on kite megascaling theory-of-operation (please excuse some review)-
      Several  kite design principles promote megascaling potential. Aggregation into stacks, trains, & arches is an old practice. For single kites, Dave Culp (KiteShip) identified "single-skin" construction with "minimal energy" surface geometry; these are the basis for KiteShip's OL ship kite, the world record holder for the largest steerable power kite. Five years ago, then collaborating with KiteShip, i asked DaveC to list all the ways he knew that big kites can be passively stabilized. He said, "well, (one) can "stake-out" a big kite." The remark did not make a sudden impression, as the mission was to fly OLs from a ship, probably as a single line kite, with "control pod" actuation. I continued to test professional kite methods & flew big kites off arched lines after the model of kite showmen David Gomberg & Peter Lynn. I discussed with Peter the "autozenith" feature of his (& others) power kites, & he laughed when i found an obscure stability mechanism in the wing-tips, but missed the major one; that a kite control bar, held crosswind, in effect stakes-out the kite. Kay Buesing exposed me to kite arches over a period of four years via the World Kite Museum's annual "Kite Train & Arch Day". Washington State has for two decades been the "world center of kite arches", thanks to Kay. Kite arches set crosswind were consistently found more stable than single kites (aggregate stability). Flying many kinds of giant kites on single lines revealed linear limits of single-line passive stability (dimensionless time analysis).
      The lesson of these varied clues was that the major scaling limit to kite structure is insufficient passive stability. A huge soft kite can be built & flown, but one cannot count on active actuation to be either powerful or fast enough for "five nines" reliability, especially with airborne actuation. The only way to get powerful passive stabilization is to stake-out the kite. The challenge is to see that the stake-out mechanism scales to tens-of-km across, with the top of the kite arch structure easily able to reach our "ultimate" 10,000m altitude. Smaller megascale kites can be rotated by "compass belay", but the largest sizes require a radial line stake-out pattern with phase tracking (Iso methods). In effect the kite arch now becomes a kite dome & can be angled for any wind direction or "wobbled" to sustin flight in calm. Various means exist to operate safely over populations & other surface conditions.
      Stake-out involves "captivity factor" & also exploits the ground surface as "free" megascale compressive structure. Ground based actuation allows the fastest most-powerful response using industrial winches & no regard for flying-mass limitation. Bulk industrial actuation evades the aerospace component pricing trap. Megascale kite structure, as single control thread, eases realtime latency control computation challenges. Its pretty cool that we are not limited to dinky mesoscale single megawatt AWECS concepts, when what we really need is gigawatts.

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