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.
~Dave Santos Sept.
20 , 2010 M
Comment and development of this topic will be occurring here.
All, send notes, drawings, and photographs!
Terms and aspects:
- "Everything should be made as simple as possible, but not simpler."
Commentary is welcome:
- "flying rope"
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"
- 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.
- Some kite arches are
complex-shaped "ropes" that fly. Consider Mothra.
- 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
- ropes used in
- the ropes that are
flying in a flight system
activities such as zip-line riding is called "flying rope"
~ JoeF 4Feb2014