CoolIP index                                                          Most recent edit: Thursday October 10, 2013              SearchSite

* See legal note below.

Modulating Kite Dutch-Roll Instability for Optimal Pumping Force

As is well known, a power kite can be "staked-out" crosswind to reduce yaw instability*. An inventive leap is that varying the set geometry (and resultant altitude and crosswind distances) can make the emergent pumping force highly controllable (including maximizing dynamic-stability) for AWES use. By basic rigging means of pulleys and reels, one can set a staked-out kite to passively oscillate in a desired power-generating mode. Variations in wind and load can be better matched.

When a kite is flown from two crosswind anchors set far apart, an adjustable pulley bridle set low between the two lines effectively modulates yaw instability. Drawing the two sides together aloft causes the emergent oscillation to increase in amplitude (at a somewhat slowed frequency). Normal mode frequency is closely modulated by altering the side line lengths. Shorter lengths host higher-frequency modes.

A pilot-lifter kite set above the oscillating kite allows more aggressive power extraction by helping keep high-performance chaos risk within critical bounds, as a further modulation control. These concepts can be implemented in high unit-count crosslinked-arrays as well.

* AKA "Dutch Roll", which involves both roll and yaw components. Note also that a "dancing kite" with relaxed lateral stability is desired (ie. no tail)
  • CC BY NC SA         ~Dave Santos         10Oct2013      Discuss at  airbornewindenergy10304

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

  • Terms and aspects:   
    • dancing kite
    • Dutch roll
    •  
  • Related links and concepts:
    •  
  • Commentary is welcome:
    •  

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

*Legal Note: coolIP is hereby defined as a Creative-Commons Unported NonCommercial Share-Alike License,
so now we are integrated with the latest standard cooperative IP model, but "coolIP" remains a nice shorthand.