Vertical-line AWE
methods
Recent posts described vertical kitelines set by low-angle guy-lines to
windward. It was shown that a wide-format kitefarm can be rigged to
consist mostly of vertical lines. An application example of vertical lines
was suggested, as halyards to suspend turbines & membrane wing-wills
directly over their surface work-cells. Many such uses are enabled by the
unique properties of vertical lines. They are gravity-aligned,
wind-direction-neutral, & the shortest path to altitude.
Vertical is a new "crosswind" geometry for a tethered-foil to follow, as a
vertical zip-line, pulley loop, or elastic-return line. Far more wings can
operate in the same airspace, by plunging up & down as pumping-trains,
than common back-&-forth AWE schemes allow. A light wing easily climbs a
vertical line faster than the wind. The plunge back down is a high-speed
dive, but under captive control, especially with elastic-return. Vertical
self-oscillation, triggered by line-bow phase, is an elegant passive
steady-state wing tacking mechanism.
A century ago Cody developed a clever system of graduated rings & cones on
kites & lines as programmable stops & passes for sequenced launching. The
"Austrian" theatre curtain is an upside-down vertical rigging model, with
drawlines gathering or deploying material along sewn-in rings. Vertical
line arrays lifted by pilot-lifter kites can guide complex 3D meshes
aloft, just as traditional circus canopies ran up erected tent-poles by
their bail rings. Unlike a circus tent, multiple levels of AWE structure
can be raised in orderly sequence according to conditions, especially to
conform to calm & storm. Return loops in the array interstices allow every
flying component to be hot-swapped freely
Kites singly or in trains will happily reside on a vertical line,
providing lift to the line without fuss, regardless of wind direction.
This is not the weak lift of a high L/D kite near zenith. Vertical kite
towers can displace rigid towers in many applications. Vertical-trains can
rise from a packed stack in a small box & return there passively, by
gravity.
The simplest vertical-line case is a single guy set at an angle shallower
than the pilot-lifter's leader to pull a second line into vertical
position. A vertical line can be dynamically anchored by by a castored
cart or hanging teabag-mass, typically water or sand-bag free to be
briefly lifted & dragged around ("tea-bagging").Three guys rigged as a
shallow tripod can hold a fourth line vertical, as wind freely veers. Let
a kiting Whiskey-Line be defined as a spacial case of guy-line; an adjunct
or improvised guy-line to haul a vertical line or array into shape. (The
usage is from commercial fishing where an extra trolling line was set over
& beyond the standard lines "to pay for the whiskey")
Planar Symmetric Arrays (PSAs) do not veer around the wind compass like
single-anchor AWECS. Vertical lines are natural PSA feature. Non-rotating
arrays do not sweep large areas like single anchor AWECS, but are
inherently constrainable to narrow corridors for forced-landing
containment.
CoolIP
~Dave Santos , 2010
M2392
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