Most recent edit:
Wednesday October 24, 2012
* See legal note below.
Mid-Span Reefing of Megascale Parafoils
Rob Creighton asked how giant soft-wing
power-kites could reduce CL (Coefficient of Lift) for stable
One well-developed solution is Mid-Span Reefing of giant cargo parafoils.
The technique was developed for US Army cargo drops as a means to reduce
opening shock of the packed parafoil. Its a standard method closely
related to the sliders used in sport parachuting for the same purpose.
Such techniques generally will work in reverse (back-drivable) for AWES
use in modulating CL.
Cargo Parafoils are a close analog of Power Kites under any Similarity
Analysis. They have been proven to scale past 1000 m2 with reefing and
steering capabilities. Unlike rigid wings, the ultimate megascale limit of
variable CL soft-wing is unknown, with no looming scaling law
as a barrier. The mid-span reefing method uses drawlines and rings or
grommets across ram-air cells to let them open (or close) controllably.
The reefed unit flies stably with a far lower CL.
Unlike reeling AWES with soft-wings, reefing is not the operational basis
for direct crosswind or short-stroke AWES generation schemes, but can
serve for matching the wing to wind conditions and to facilitate
~Dave Santos 5
Comment and development of this topic will be occurring here.
All, send notes, drawings, and photographs!
- Terms and aspects:
- Related links and concepts:
- Variable area
- Variable porosity
- Variable geometry
- Pinching, gathering, collecting,
- Segment depowering
- Shading, hiding
- Furl, furling
- Commentary is welcome:
Note: coolIP is hereby defined as a Creative-Commons Unported NonCommercial
so now we are integrated with the latest
standard cooperative IP model, but "coolIP" remains a nice shorthand.