Dave Santos,

Could you gather contributions from players wanting it,and provide to KitePower a single manuscrit (pdf 12 p.maxi as indicated) under AWEIA banner ?

The title could be:"global efficiency and ratio of swept area/occupied volume and space",or similar.

Indeed this point seems gather players like yourself [Mothra],Roddy [Rings of kites,Complexes of Arches...],me [OrthoKiteBunch,Airborne Seaborne Wind Energy System where the rotor(s) is held both by sea and by air], DougS ,MassimoI (Stem-farm and Carousel) and perhaps others.This very important point (before reliability because reliability without global efficiency has no economic sense) is for the moment underrated.

As Saül Griffith generally indicates such a paper should be clear enough to be understood by students in concerned fields.Physics should be verifiable, calculed,and accepted.So theories like phonon-waves-short oscillating should be submitted on a separate paper ("Other power conversion"mentioned by KitePower as topic).

In case of acceptation it will be good.In case or reject things will be clearer.

With thanks.

PierreB

http://wheelwind.com http://www.worldenergy.org/documents/congresspapers/155.pdf  (OKB)        Issue 2.5 – World Energy Council   http://www.energykitesystems.net/OrthoKiteBunch/ProjetEOLICARE.pptx  (20 mo)                                           http://www.energykitesystems.net/OrthoKiteBunch/Presentation2010WEC.pdf (14 mo)

DaveS,

Some questions:are short-strokes involve effective and recovery strokes?If yes recovery short strokes should imply losses like long strokes.Are metachronic waves divided into antiplectic and symplectic waves?If yes how is it possible to control them?Can you provide calculations?(note:I know nothing about metachronic waves but it is not the only thing I dont know) Can you indicate how the generators work?Can Roddy provide a realistic animation of the set?

In a recent post you indicate hundreds 50 m² kites.Nor "neutral-buoyant mass by carrying along internal air" is something like 10 m3; 200 (50m² kites) will be roughly 2500 kg for air,the same for materials.For MW-scale,it is neglectible.With 500 m² kites x 1000 (expected 1 GW for crosswind parafoils) air mass is roughly 100 tons,yet too low to take it into account. Morever mass is not energy,but in this case can be a small storage.But perhaps this mass helps for the complex motion you suggest.How does air-materials work? 

Kites with L/D ratio is 1 like you indicate could provide something like 15% (in absolute or on Betz limit,I dont remenber) by going downwind.This small efficiency is probably at least lost during recovery stroke.If case of no loss,to obtain 1 GW you must have a swept area of 6 or 7 Gm² (6000 km/1 km) of kites (1000 km/1 km) with 15% solidity for example,very very roughly,and being very very optimist.Reel-out/in DougS critics (being right or wrong) looks very efficient beside.

It looks like a non reasonable way for AWE (if AWE is a reasonable way for wind energy) unless important discoveries are made,implying Nobel prizes.

PierreB 

Correction:"swept area roughly 15 km/1 km of kites (2 or 3 km/1 km)" instead "swept area of 6 or 7 Gm² (6000 km/1 km) of kites (1000 km/1 km)" too roughly. 

PierreB 

In my sense "realistic animation" does not concern your work,Roddy,but the possibility to make a "realistic animation" with the scheme described by DaveS,which seems to be a little like Windbelt - Wikipedia, the free encyclopedia,but not quite since this scheme seems contain both torsion and short-stroke (note that torsion pushing farer becomes rotation).

DaveS:if elasticity is an important parameter,should not be a membrane-shape more adapted to keep kinetic energy and high speed if it is possible?I dont see kites short-strokes in an other way than effective and recovery strokes where the average speed is low,the kite having not enough distance to accelerate,and where drag during recovery stroke stays (I dont see how it is possible to make energy);but if kites vibrations are really at high velocity,the ram air-mass you mention as advantageous can be a problem by preventing alternating motion.

PierreB   

(Developing the offshore wind supply chain)

Claws
Not sure what my terminology for the ends of skybow arches strung vertically across the face of a lifting bow would be.
Maybe follicles
Got to be fairly easy to gang those outputs together along a gang cranked line between lifting arch feet. 

Tip to Speed Ratio (TSR) for Wind Turbine Blades: How to calculate  and

Wind Turbine Blade Calculator - Warlock Engineering  seem indicate with more blades TSR is lower,torque is higher,power is the same (but ?).Maybe the reason is 5 blades for less TSR,so less noise and vibrations;but a more expensive generator or/and gearbox should be used.However 5 blades could be interesting for a Rim-Driven design where generator works in tip blades,a lesser TSR being less problematic.Actually as you know advantages and inconveniences of different systems show classical 3 blades with generator in the axis as winner. 

PierreB

http://wheelwind.com (in this Rim Driven design blades could be also used as spokes:more blades,better circular shape,and less drag due to the Rim at too high TSR;here Rim-Driven configuration having advantages as generator at sea level,and turbine support both by sea (floating station) and air (cascad of lines))

http://flygenkite.com

Fly a Mothra offshore. Two hollow centre ring barges movable around a running anchor ring. In the centre of the barge rollers form a mangle. The Mothra tethers run through the mangle. The tethers are made from an upside down hot air balloon like structure.
When the balloons are full the kites are set to lift. As they are lifted up and through the mangle water is forced out through a gland and pipe to a generator.
This could be done side at a time for continuous generation.
Once bag is drained the kites depower. A weighted ring or a rope and motor pull the bag back down to refill.

What Massimo says and makes about patents is not different of other CEO in AWE and other fields.Investments are made about patent basis to protect founding.Often some patents of a firm have nothing to have with the worked technology but concern some details without high importance,said worked technology being mainly covered by prior art.But also often after such a necessary temporary gap to attract investors,real novelty comes (it is the case for Makani,for example) from experiments and is claimed.  

Like DaveS and other like me indicate,a moutain of prior art and hidden claims cover the fondamental which is nethertheless subject of technical discussions.Probably startups have studied different schemes before choice,even if it is not quite sure fondamentals and linked parameters(groundgen,flygen, hydroturbine...,that in relation to economic issues induced by ratio swept area/used space) are completely understood by putting the different parameters together.

This forum should be also and even in first a mean to receive technical critics from  developers in AWE startups and universities and also in classical wind energy about our schemes.

Concerning KiteGen,Massimo is a historing leader in AWE,introducing great possibilities in AWE.Morever he proved open spirit by discussing technical issues in our ("our" should contain developers in firms if they want) forum.I would be happy he discusses (and critics!) our schemes,helping us wasting time for some obviously no workable schemes.

PierreB

PierreB

http://flygenkite.com