CoolIP index                                                          Most recent edit: Wednesday January 16, 2013

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Airborne Harmonic Nodes

This is ongoing clarification of once-mysterious methods-

FlipWings (membrane wingmills) are anti-nodes, the moving part of a harmonic AWES system. Because they are less obvious, we have hardly considered the static harmonic nodes as such; like the ground/anchor point, the pilot-lifter kite, and corner-block drogue, as a simple single-unit case.

Ideal AWES harmonic nodes are solid and stiff, so as to dissipate as little harvested and transmitted energy as possible. Therefore, the ground is an ideal AWES node, but kite-lift and drogue-tension node design needs to be optimized to present as much embodied mass and aero inertia as possible in the direction of motion. Natural kite-and-wind mass and elasticity are inherent to self-oscillation.

In practical terms, this means that a larger lifter kite and drogue is better (up to a point). They should be made with low-stretch low-porosity material. Node mass and sail area directly opposed to antinode motion both count. Pure ballast mass can even be a useful airborne node.

A static-nodal wing is tensile balanced at its static CE. An antinodal wing is LE attached, like a flapping-flag. Its CE moves fore-and-aft and flips sides with each flap. Mass-spring resonance of both the hardware and flow regulates the action.

As an example of what might be possible, consider a "laddermill" consisting of alternating nodes and anti-nodes in a powerful stable "ladder" oscillation of standing waves tapped at the base. It would not need to rotate weakly in an endless loop; instead the antinode wings would sweep crosswind in well ordered passive harmonic synchrony. A test will be devised to see how well this sort kite train does.

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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