CoolIP index                                                          Most recent edit: Wednesday March 27, 2013

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Giant Kixelated LoadPath FlipWings (Mothra-FlipWing Hybrid)

Announcing AWE's New Baby, the Kixelated Loadpath FlipWing, whose parents are Mothra and FlipWing.

KiteLab Ilwaco continues to make and test FlipWings (since 2008), with small versions working at high TRL. They are very simple and cheap and seem to offer the highest power-to-weight potential of any WECS principle known; and thus can scale greatly. It has long been proposed that FlipWings can ultimately scale to >300m long, far beyond any practical rigid wing or rotor. The many small experiments so far involved battened sails of fairly conventional construction (sewn fabric or membrane sandwich).

Its now seen that Mothra-like construction is also suited to make cheap giant self-tacking FlipWings. The pattern-language consists of simple rope loadpaths with "tarp kixels" hanked on, with periodic single-sparred LE control sections for luff stability. Such FlipWings would hang in arrays under a Mothra Arch, and be configured to fire and tack in metachrony. They would be specially specified and rigged to sweep at a higher apparent wind than the parent arch. The wing fabric would be somewhat heavier, the sails closer trimmed, with more batten-spars closer-spaced along the leading edge.

It is crudely estimated that a single 300m FlipWing could rate at ~5MW, with a ~6,000m2 area (depending on windspeed, with an apparent wind of up to about 3/1 (like a TSR). The base price of such a wing would be low; only about 50k USD.

Such monster FlipWings are predicted to self-tack with good regularity, owing to increasing spring-mass with scaling. They will probably sound like large crashing surf; or even thunder, in high wind. Current concept rigs of mixed Arch-FlipWing configuration range from bird-like to krill-like, but with the biomimetic form flipped backward, to be driven, rather than driving. Crosslinked FlipWing AWE arrays would be quite close in spirit to Wayne's "Vertical Blind Affairs".

It will be quite exciting to fly-off such megascale designs against far-smaller more-complex contenders of comparable capital-cost.


A Note to Rod, who has been wonderfully modeling Mothras of his own variations. A further refinement is to design them to take on a wider-shouldered horse-shoe frontal shape to more closely fill the 600mH x 1200mW airspace. The central arch control section makes a sort point, so the supposed optimal form is like a curly-bracket on its side that closely fits the projected airspace rectangle.

Comment and development of this topic will be occurring here.       
All, send notes, links, drawings, papers, videos, plans, safety-critical findings, and photographs!

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