Hi-Fi Biomimetic Kite Farm Model (Shark Gills)
What will a megascale kite or kite farm of the future
look like? Many concepts call for a sprawling pattern of single line AWES,
resembling thin sparse hair, but a quick review of shark-gill images
reveals a more attractive model for a compact kite farm able to utilize
airspace and land footprint up to 100X the sparse models [KiteLab 2011].
For over 400 million years, shark-gills have embodied a highly optimal
geometry to process flow in order to catalyze blood oxidation (and feed).
The gill slit structure is a set of staggered compliant span-loaded wings.
Staggering is far better than stacking, as staggered wings condition the
flow between wings, acting as detached eddy flaps. Stacked wings interfere
with each other, the high pressure under one wing canceling the low
pressure over the one below, so kite stacks require enough spacing for the
staggered condition to dominate.
In the case of kite farms, we know that scaling laws impose severe limits
on individual WEC units, that many units must be aggregated into dense
non-interfering arrays that are ideally flown as one control process.
Shark gills provide a clear model for how to arrange such a fractally
recursive fluidic structure. The primary cartilaginous gill wing structure
is even called a Gill Arch, just as this sort of crossflow wing is called
a Kite Arch, anchored crosswind. The fine harvesting structures are called
Gill Lamellae and correspond to Kite Flares as WingMills, or even strings
Sharks have two general modes of respiration; ram-flow by moving forward,
and pumping flow by gulping. Both are interesting AWES models, pure ram in
faster flow, and a galloping oscillation in slower flow. Primitive sharks
mostly had six Gill-Arches; modern sharks have five, and the bony fishes a
one-slit structure. Sharks remain the largest of fishes, so the
"divide-and-conquer" scaling principle is suggested, that more Gill Arches
serve for larger and/or more primitive designs.
KiteLab Ilwaco intends soon to build and test multi-arch
structures according to the Shark Gill model.
~Dave Santos 18Feb2012 AWES5652
Comment and development of this topic will be occurring here.
All, send notes, drawings, and photographs!
Terms and aspects:
- kite-energy farm, kite farm, wind-energy farm, WEC farm,,
Harvest the kinetic energy of the wind at the farm!
Related links and concepts:
Commentary is welcome: