CoolIP index           

Self-Lifting Tethers for High-Altitude Apps

Dave Culp has long had a pet idea of "flying-rope" as consisting of many tiny kites strung along a line. Just toss it out in wind to fly it. James Macnaghten calculated that stratospheric kites will too-easily have miles of tether lay on the ground in weak wind. The problem is that long "bare" tethers accumulate weight, drag, & negative-lift as tremendous down-force. KiteLab found empirically that even high-speed reeling might not keep up with the characteristic "slight-slack/sudden-sag" effect. Lang saw the effect in simulation.

Why not put lifting kites all along a high-altitude tether? Call it a kite stack or train, its really just a macro version of Culp's winged rope. Sudden-sag would be slowed by lift & aero-resistance all along the line. Optimal high-altitude kitefarms may take form as fuzzy-looking latticeworks of self-lifted lines covered with kites.

Existing absolute kite altitude records are held by (sparse) trains, not single kites, showing an advantage for multiplied lift. There are handling trade-offs to Self-Lifting Tethers, but the good news is that the method offers hope for eventual high-altitude AWE & related aviation.

CoolIP                       ~Dave Santos            Sept. 20 , 2010        M
 


Comment and development of this topic will be occurring here.       
All, send notes, drawings, and photographs!   Notes@EnergyKiteSystems.net

Terms and aspects:   

  • "Everything should be made as simple as possible, but not simpler." ľA. Einstein          

Related links:

Commentary is welcome:

  • "flying rope"                          "self-lifted line"
    • See KiteTrains   where well-spaced wings on a tether result in a global "rope" that is well lifting along the length; stand back visually and let the image of wings blur into a macro image of "rope."  A separate lifter kite is not needed beyond what appears from a distance as fat rope flying. Just how tiny might the segment wings be in a kite train to effect a "flying rope" status for the macro structure?
       
    • Dave Culp proposed a continuous linear soft kite for "flying rope". Details for the structure envisioned are not forward yet.  Santos extended the term to "self-lifted line"      Ref1     Ref2 
       
    • Rotating-tape or rotating ribbon kites are flying rope of particular shape and held by two anchor stations.  Such are one sort of kite arch.     KiteArch
       
    • Some kite arches are complex-shaped "ropes" that fly.  Consider Mothra.   KiteArch
       
    • A continuous line or rope hung from of a kited wing will have positive lift and positive drag as the wind impacts the windward surface of the rope. Many streaming tails of kite systems are essentially lifting flying ropes of particular shape.
       
    • http://www.kitepower.com/stacking.html
       
    • ropes used in flying
    • the ropes that are flying in a flight system
    • Sometimes activities such as zip-line riding is called "flying rope"

    ~ JoeF    4Feb2014