Messages in AirborneWindEnergy group.                          AWES 18653 to 18702 Page 267 of 440.

Group: AirborneWindEnergy Message: 18653 From: joe_f_90032 Date: 8/8/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18654 From: benhaiemp Date: 8/9/2015
Subject: Re: Rolls Royce Sailing Cargo Ship

Group: AirborneWindEnergy Message: 18655 From: dougselsam Date: 8/9/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18656 From: christopher carlin Date: 8/9/2015
Subject: Re: Rolls Royce Sailing Cargo Ship

Group: AirborneWindEnergy Message: 18657 From: benhaiemp Date: 8/10/2015
Subject: Betz coefficient and swept area

Group: AirborneWindEnergy Message: 18658 From: benhaiemp Date: 8/10/2015
Subject: Re: Betz coefficient and swept area

Group: AirborneWindEnergy Message: 18659 From: benhaiemp Date: 8/10/2015
Subject: Re: Betz coefficient and swept area

Group: AirborneWindEnergy Message: 18660 From: dougselsam Date: 8/10/2015
Subject: Re: Rolls Royce Sailing Cargo Ship

Group: AirborneWindEnergy Message: 18661 From: dougselsam Date: 8/10/2015
Subject: Re: Betz coefficient, swept area, intercepted area

Group: AirborneWindEnergy Message: 18662 From: joe_f_90032 Date: 8/10/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18663 From: dougselsam Date: 8/10/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18664 From: dougselsam Date: 8/10/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18665 From: benhaiemp Date: 8/10/2015
Subject: Re: Betz coefficient, swept area, intercepted area

Group: AirborneWindEnergy Message: 18666 From: dougselsam Date: 8/10/2015
Subject: Google spins off X

Group: AirborneWindEnergy Message: 18667 From: stephane Date: 8/11/2015
Subject: Le Scubster, une star sous-marine...

Group: AirborneWindEnergy Message: 18668 From: joe_f_90032 Date: 8/11/2015
Subject: Kite Energy Systems

Group: AirborneWindEnergy Message: 18669 From: joe_f_90032 Date: 8/11/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18670 From: dougselsam Date: 8/11/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18671 From: joe_f_90032 Date: 8/11/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18672 From: dougselsam Date: 8/11/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18673 From: benhaiemp Date: 8/12/2015
Subject: AWE TU Delft Online

Group: AirborneWindEnergy Message: 18674 From: joe_f_90032 Date: 8/12/2015
Subject: Stairway to Heaven

Group: AirborneWindEnergy Message: 18675 From: joe_f_90032 Date: 8/12/2015
Subject: New AWE

Group: AirborneWindEnergy Message: 18676 From: joe_f_90032 Date: 8/12/2015
Subject: Re: New AWE

Group: AirborneWindEnergy Message: 18677 From: joe_f_90032 Date: 8/12/2015
Subject: WO2014199407 A1

Group: AirborneWindEnergy Message: 18678 From: joe_f_90032 Date: 8/12/2015
Subject: Re: WO2014199407 A1

Group: AirborneWindEnergy Message: 18679 From: joe_f_90032 Date: 8/12/2015
Subject: Re: WO2014199407 A1

Group: AirborneWindEnergy Message: 18680 From: dougselsam Date: 8/12/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18681 From: Rod Read Date: 8/13/2015
Subject: Massive Depower

Group: AirborneWindEnergy Message: 18682 From: Rod Read Date: 8/13/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18683 From: benhaiemp Date: 8/13/2015
Subject: Re: Massive Depower

Group: AirborneWindEnergy Message: 18684 From: Rod Read Date: 8/13/2015
Subject: Re: Massive Depower

Group: AirborneWindEnergy Message: 18685 From: dougselsam Date: 8/13/2015
Subject: Inflatable tower - farfetched?

Group: AirborneWindEnergy Message: 18686 From: joe_f_90032 Date: 8/13/2015
Subject: Re: Inflatable tower - farfetched?

Group: AirborneWindEnergy Message: 18687 From: joe_f_90032 Date: 8/13/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18688 From: benhaiemp Date: 8/13/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18689 From: benhaiemp Date: 8/13/2015
Subject: Rotating Reeling : asking for simulation

Group: AirborneWindEnergy Message: 18690 From: Joe Faust Date: 8/14/2015
Subject: Calm-or-Low Wind Arch Kite Flying

Group: AirborneWindEnergy Message: 18691 From: Joe Faust Date: 8/14/2015
Subject: Re: Calm-or-Low Wind Arch Kite Flying

Group: AirborneWindEnergy Message: 18692 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18693 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18694 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18695 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18696 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18697 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18698 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18699 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18700 From: benhaiemp Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18701 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Group: AirborneWindEnergy Message: 18702 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.




Group: AirborneWindEnergy Message: 18653 From: joe_f_90032 Date: 8/8/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Already, I offer some discomfort over the first trial definition of "wobble of a wing" in that there seems to be a pressure not to restrict the return motion to be exactly 180 degrees relative to the first motion. Perhaps a return motion could be 179 degrees away from he first motion; or 2 degrees!  Etc. Or 5.67 degrees.
Group: AirborneWindEnergy Message: 18654 From: benhaiemp Date: 8/9/2015
Subject: Re: Rolls Royce Sailing Cargo Ship

Both Peter Lynn and Mike Barnard produce fine analyses based on facts then extrapolations, as robust basis for fruitful discussions. What a change with regard to hazy theories and rotating (but without wanting producing any kW) words bitting their  tails!

In my opinion the main problem (for kite system) Peter Lynn raises is the particulary high level of efficiency of fuel for a cargo: "Fuel use per tonne km is perhaps 70 times better for a container ship than for a truck or train- they're VERY fuel efficient."


PierreB

FlygenKite - Kite wind turbine - Eolienne cerf-volant 

 

Group: AirborneWindEnergy Message: 18655 From: dougselsam Date: 8/9/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Joe, when I think of "wobble" with regard to a kite, for example, I think of "roll", where the left and right sides of the kite (wings?) alternately get higher/lower.  I guess ANY repeating motion COULD be considered a "wobble", (hence the "ble", otherwise you just have a "wob") but again, this is just playing with words.  Without a specific configuration and a specific type of wobble to analyze, it seems just more wordplay: "solutions in search of a problem" in "wordland".  A rose is a rose by any name, and whether anyone has a configuration with a chance of success would be unlikely to depend on some temporary word definition of "wobble", in my opinion. 

You're making the case for endless analysis, but with really nothing to analyze.  I'd call it a case of "paralysis by analysis", except I'm not seeing any other productive course that the purported analysis is keeping you from.  I really think it falls under the category of "How many angels can dance on the head of the pin?" - depends on the pin, depends on the angels, etc. 

What I'm picturing is a guy who keeps asking himself about one word definition after another, to the point that he is walking slower and slower, asking: "What is it to "walk"?", "What is it to balance?", "What is my "foot", really, anyway?", until his confidence that he even HAS a foot is brought into doubt, and he can no longer take even a single step, now completely paralyzed, by endless analysis, desperately seeking one "theorem" after another, in the attempt to substitute words for the real world.  Finally, in a completely motionless state, he announces a "proof" that he is "walking", barely noticing that he has not taken a single step in quite some time.  He has become motionless, in the effort to "prove" his motion.  "Help I can't move" "Why?" "I'm too busy "proving" a "theorem" to "define" the word "walking" and it has stopped my progress!  Can anyone help?  I'm getting tired from standing here!"
Group: AirborneWindEnergy Message: 18656 From: christopher carlin Date: 8/9/2015
Subject: Re: Rolls Royce Sailing Cargo Ship
I’m surprised at the twenty times number although I’d certainly agree it’s a big factor. One should really take into account loading unloading and all that. The fuel efficiency is actually good news though because it also means they easily driven under sail. The argument in the Rolls article about sulphur content may be as significant as anything else.

Regards,

Chris
On 9 Aug 2015, at 10:09, pierre.benhaiem@orange.fr [AirborneWindEnergy] <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 18657 From: benhaiemp Date: 8/10/2015
Subject: Betz coefficient and swept area

JoeF wrote : "Perhaps some of the confusion that Pierre mentions about whether or not an AWES is a cross wind system or not could be clarified by the present proof process, and perhaps followed later by other proofs on associated matters."

Indeed I tried to see rotating wings as "crosswind kites" with constraint move. And DougS also mentioned "crosswind kites" terms as problematic , since conventional wind energy already works (and even more strictly) crosswind.

Probably "crosswind kites" are considered in opposition to " statics kites ". The same is not possible for a rotor of conventional turbine. So the double fonction of kite system (lift and convert) is well visible.

But instead of used formulae taking account of performances by wing area, I would prefer terms used in current wind energy as Betz coefficient by swept area as being the whole area contained in eight or circle figures or by rotation. Thus some maximisation concerns as space used would be clarified.

PierreB

Rotating Reeling

Group: AirborneWindEnergy Message: 18658 From: benhaiemp Date: 8/10/2015
Subject: Re: Betz coefficient and swept area

Precision: "since conventional wind turbines already works (and even more strictly) crosswind."


PierreB

Rotating Reeling



Group: AirborneWindEnergy Message: 18659 From: benhaiemp Date: 8/10/2015
Subject: Re: Betz coefficient and swept area
Correction again: "since conventional wind turbines already work (and even more strictly) crosswind."



PierreB

Rotating Reeling


Group: AirborneWindEnergy Message: 18660 From: dougselsam Date: 8/10/2015
Subject: Re: Rolls Royce Sailing Cargo Ship
For 2015, sulfur content in Archie Bunker fuel for container ships has been dropped to near zero, in affected areas, by world agreement.  Here's a link:
Low Sulphur Fuel - Hapag-Lloyd

  Beyond that, remember that atmospheric sulfur has been cited as likely causing "global cooling" by reflecting the sun's rays, so from that standpoint, burning sulfur is (supposedly) "good".  There are many angles to consider.  :)

Group: AirborneWindEnergy Message: 18661 From: dougselsam Date: 8/10/2015
Subject: Re: Betz coefficient, swept area, intercepted area
Swept area of a wind turbine is the area swept by the working surfaces.
Intercepted area is the area of the structure as seen from the direction of the wind.

For regular turbines, hence in the art of wind energy as currently practiced,  the two terms are used interchangeably, since a turbine approximately "sweeps" it's entire intercepted area.
When we get into, say, ducts and shrouds, a less-materially-effficient use of intercepted area is subsituted, with the total intercepted area being greater than the swept area of the blades.  So in this case of ducts, the "swept area" is less than the intercepted area.  Some in the industry might call that greater intercepted area "swept area" out of habit, but they certainly know the difference.

In the case of a Savonius, the USEFUL part of the intercepted area is actually LESS than the swept area, since the upwind half of the rotor is USING power, not MAKING power.

For tilted and skewed rotors, the swept area is also greater than the intercepted area, by trigonometry.

Of course, all this gibberish mainly serves those with a scant understanding of how turbines work, since for those who do, most of this is obvious and barely worthy of mention.  Nonetheless, the vocabulary of wind energy has been in place for quite some time, and endless analysis of it is probably not going to help much.
Group: AirborneWindEnergy Message: 18662 From: joe_f_90032 Date: 8/10/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Doug, ... so many subtopics within the topic!   Each subtopic may have its space. Shotgun treatment glosses over some potentially core matters. So, this note does not pretend to face all the mentioned subtopics, but eventually it is my aim to attend to your mentioned subtopics.   Here are some of the subtopics that I sense:

1. Proof processes.  Types.  Choices. Styles. Importance. Historical examples of relevance and impact.

2. Role of definitions in engineering, science, craft, AWE.

3. Assumptions. How one may not have an infinite preamble, but that some assumptions are needed. Does the set of assumptions bring contradictions or not?

4. Choice to avoid logical proofs.  Choice to engage in logical proofs.

5. Distinction between idealized scenarios and actual materialized practical scenarios.

6. Perspective appreciation.

7. Possibility of many proofs of some particular theorem. Elegance of proofs. Hierarchy of elegance of proofs.

8. What information is already available that might play in a given proof process?

9. Will having a particular theorem have usefulness?

10. Progress without explicitly having proved theorems.

11. One might "see" something clearly; such might amount to a holding of a personal theorem; such may not be in a form that is publishable in text. Such might not be sharable in a community. Yet, the holding person still "sees" a matter clearly.  Making the clarity communicated to others in a scientific community may well require sharable proofs.

12. Roles of different members of a scientific community.

13. That some attention on a topic does not necessarily mean that other topics are remote.

14. That some attention on a proof process does not necessarily mean that other practical AWE projects are neglected.


=========================

The above does not exhaust the glanced subtopics noticed so far in this topic thread.

=========================

During an effort on a proposition up for proof, one might arrive to the conclusion that the proposition cannot be proved; in such case, it may loom that the proposition might be true yet unprovable (at least in the prove methods known, so far). Or some success might be attained to show a proposition is surely false by proof.


The present topic: "Prove a particular kited wing as non-cross winding"

invites putting up a well-described "particular kited wing" and proving it is "non-cross winding".   Well, is that asking for some impossibility or not?  Maybe it can be shown that no well-described kited wing could be "non-cross winding".  The text presentation of the optional courses is not yet up and clear to me. Some persons might have their personal "see" moments and "see" some resolution on topic; their "seeing" is invited to be text described carefully to see if others may "see" from the persuasion of the text argument.  


If it can be shown that all kited wings are necessarily "cross winding" then the topic can be resolved quickly; as such proof would mean that the proposition that of some particular kited wing be non-cross winding has zero chance of being proved.   But, I have not the proofs either way yet.  And I do not "see" yet a resolution, but have some discomfort hunches that lead me to care.   The why of "care" does have practical importance for my cares to advance kite energy.   What exactly it means to cross wind or to not cross wind seems fundamentally important to guide design systems, construct systems, and experiment with kite energy systems.  


Is there a time when some kited wing is not cross winding?  Is there an elegant proof in the ether for the scene?  Aerodynamicists, logicians, kite engineers, ... are all invited to the challenge of proving the matter.


Doug, thanks for your time and effort. And I hear your exasperations too during the effort. Your perspectives are being studied.  Yet, there are differing perspectives. 


Yesterday, I accidentally had a PTO on a kited wing that was joyfully observed and heard. The kited wing was a tumbling wing set in a traverse-to-wind arch format. The upper part of the wing was moving downwind; the lower part of the wing was beating its way upwind while coupled with the upper part of the wing. In my crafting I left some wing just so the wing part rotated and hit the arch load line once per rotation; the hitting was tiny but just enough so that the wing part was bent just enough to be able to bend back to its  rightful place. The net result was a built-in PTO that slightly damped the rotation of the wing while putting some energy into the air in the form of sound or noise: flap, flap, flap.  Some of the PTO energy went into bending and heating the wing and the air.  I asked myself, was the upper part of the wing going downwind cross winding or not?  And I asked myself, was the lower part of the wing that was going windward cross winding or not?   My gut was telling me that, if even if I did not yet have words for it, that somehow  there had to be some cross winding involved; but how? Ah!  The wing during the rotation is "almost always" crossing the wind; perhaps just at the infinitesimal points of top and bottom there is not "crossing".   And observing full stall, I sensed that  in some sense kiting ended and no "crossing" was occurring, perhaps.   Things to explore carefully!   




Group: AirborneWindEnergy Message: 18663 From: dougselsam Date: 8/10/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Joe I just hope you are having fun with your word definitions.
In real wind energy, we HAVE a convention to categorize the motion of the working surfaces:
If the working surface travels approximately FASTER than the wind speed, it is considered a "lift" device.
If the working surface travels approximately SLOWER than the wind speed, it is considered a "drag" device.
For that reason, farm windmills for pumping water are usually called (somewhat arbitrarily) a drag device, hence usually not employing advanced airfoils, though with rotation near the wind speed, they represent a borderline case..

It is acknowledged in the industry that this is just a rule-of-thumb, not a "proof" or anything approaching a "proof", and that there can be some exceptions, especially when the working surfaces travel at about the same speed as the wind,m where there is an obvious "borderline case".

One thing that's apparent to me is that the vocabulary of wind energy has emerged to describe real working systems that are fairly simple, so more advanced, or new types, of systems may not always fall into the exact word definitions previously established. Maybe some new descriptives are needed in any case of a new configuration, but usually it is just the "Professor Crackpot" urge to deny that a "new" configuration already falls into the well-known failure modes of previous, long-disproven configurations that leads to attempts at new vocabulary, as though new words can rescue old, bad ideas.

Beyond that, to "prove" whether a "wobble" or even a "wiggle" could possibly involve any crosswind travel is, to me, not a fruitful path, being mere wordplay rather than contributing progress, but that is just my opinion, for what its worth, and as you point out, there are many opinions, not just mine.

In a forum, all I have to offer is my opinion, my experience and knowledge, and my perspective, for what its worth.  So you gave your opinion, and I gave mine - that is good, the way it is supposed to work.  :)
Group: AirborneWindEnergy Message: 18664 From: dougselsam Date: 8/10/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Hey Joe just another thought on the topic of "proving" a "wing" is not "cross winding":
1) "Cross winding" is a term YOU have invented, therefore you can "define" it as you wish. (here we go again: defining words in lieu of progress).  Depending on how exactly you wish to "define" your own self-selected term, you can "prove" or "disprove" whether a stationary wing in a steady wind IS "cross winding" or IS NOT "cross winding".  You are also inclined to "re-define" any associated words, so you will likely be able to easily "prove" a stationary wing is, or is not, "cross winding" according to how you wish to adjust all related definitions, starting with your own definition of your own new term "cross winding".

2) If i were going to apply the term "cross winding" according to the normal, established shorthand of "crosswind" turbines versus "downwind/upwind" turbines, I'd say your stationary wing is NEITHER crosswind NOR downwind/upwind, since you have already specified it as "stationary".  The terms "crosswind" and "upwind/downwind" describe movement, so it does not even remotely apply to a stationary object.

This sounds to me like trying to "prove" a utility pole "planted in the ground" is not traveling "east/west", (as opposed to "north/south"), when in fact we already said it is "planted in the ground".  (notwithstanding the spin of the Earth, motion through space, etc., (hoping I can make a simple point without starting a NEW pointless argument with, say, a daveS))

OK so you want a "proof" that a stationary object is not traveling "crosswind"?  Here is your proof:
Assumption A: the wing is not moving.
Assumption B: By "cross winding" you mean traveling across the wind.
If the wing is not moving, it is not moving across the wind, therefore it is not moving "crosswind", therefore it is not "crosswinding".  IBID.  Let me know if that covers it.
:)
Doug
Group: AirborneWindEnergy Message: 18665 From: benhaiemp Date: 8/10/2015
Subject: Re: Betz coefficient, swept area, intercepted area

Not sure. "Crosswind kite power" projects (Makani, Tu Delft and others) are studied on a basis of performances of wing, not by taking account of swept area, even less for space used. Expected following is a forest of tethers as a farm, with no really manageable space.

In contrast studying on a basis of swept area (with correction by trygonometry), then swept area within space used, so space used, is a door towards stationary and rotating wing which is more manageable.  


PierreB

Group: AirborneWindEnergy Message: 18666 From: dougselsam Date: 8/10/2015
Subject: Google spins off X
Google has announced a restructuring whereby a parent company called "Alphabet" is formed, with today's "Google" pieces and various businesses to be held under the "Alphabet" umbrella.  Source: CNBC.


Group: AirborneWindEnergy Message: 18667 From: stephane Date: 8/11/2015
Subject: Le Scubster, une star sous-marine...
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Group: AirborneWindEnergy Message: 18668 From: joe_f_90032 Date: 8/11/2015
Subject: Kite Energy Systems

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Kite energy systems are machines performing practical works,
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The anchor set may also be viewed as another wing set.  

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Group: AirborneWindEnergy Message: 18669 From: joe_f_90032 Date: 8/11/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Doug,

       Thanks for the focus on the topic. As the cooperative project continues, your posts bring up some points that seem to further the topic.  As statements are made, some new ideas arise; each statement is being checked for gems, branching to new topics of potential worth, refinements, and possible core proof points.  I will attend to your offered statements and offered proof; checking by you, me, and others of any offered proof is part of the scientific manner. Gremlins may live in offered proofs that make the offered proof not a proof; but in the process, perhaps someone will be able to fix an offered inadequate proof.   The work of checking is ongoing. My guess is that some polished sound proofs will surface.   Again, the proposition to be proved might not be provable; and then the question will arise: Is the proposition simply impossible or are is the proposition undecidable.    You have offered a short "proof" concluding that a particular kited wing described as non-cross winding; perhaps you presented a sound proof; the community checking process has yet to occur; for you, you might "see" a soundness in your offer; the flowering in scientific community on the matter will be when others check for soundness and also "see" a proof; we are not there yet.   Look for gremlins of different sorts; was some new aspect placed that forms a different topic than the proposition of topic? Is the logic sound? Has the proposition been faced essentially?  It would be neat if you have produced a tight short elegant proof that stands up to scientific community oversight.


Some of your points in discussion while approaching an offered "proof" remain interesting.

For instance, you have stated that I invented the term or phrase "cross winding" which maybe could be cool, if such were fact.  If you can prove that I invented the term, that would be neat.   However, since the term has prior use in aviation, then I highly doubt that I invented the term!  One strict instance of priority would prove that I did not invent the term.   I offer for community review a contending counterexample in the patent by Owen Finlay Maclaren and Leslie Everett Baynes of London, England, filed in England in 1940 and in the USA in 1941  Patent US2345405 - Aircraft alighting gear


Another point in your fine discussion is the concept of "travel" which I am struggling with. The proposition does not use the term "travel" and so the discomfort yet. My effort to set up a particular kite to be used in the proposition did not use the term "travel" and so I am spending some effort to see just how the term might play in or out of the pointed proof effort for the given proposition.  Frames of reference and the meaning of travel seem to play. Does a kited wing that is stationary to ground-fixed observers "travel" or not? Could such wing be said to be traveling relative to the wind that is interacting with the wing?  Certainly sectors of the wind that is streaming to the face of the kited wing are changing position relative to the wing; the wind sectors in the oncoming widn are traveling from upwind to downwind and from away from the wing toward the wing; if the wind is traveling, then perhaps it can be said that the wing is also traveling relative to the wind. I've still some sorting to do on this matter.  My guess for the moment is that a kited wing stationary relative to the ground and a vertical projection wall in an ideal steady horizontal macro wind is not traveling relative to the ground or the vertical projection wall, but is traveling relative to the wind.  The very travel of the wing relative to the wind has a resultant of lift and drag that provides a resultant of having the subject wing be stationary relative to the ground and the vertical projection wall.  


I've some notes yet to be posted that are still toward some of your good shares. And some other points. Pause for now.  Soon.

Thanks,

    Joe F.

  @@attachment@@
Group: AirborneWindEnergy Message: 18670 From: dougselsam Date: 8/11/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
I still think you are going to define "cross winding" as you choose, as well as defining any other defining terms to suit whatever train of thought you are on at that moment, making the entire exercise really nothing more than wordplay.  An adventure in "wordland", meanwhile you've already defined exactly what you wanted to define, a stationary wing tethered in a stable position, in a steady wind.
Since you've already stipulated the exact configuration including a steady wind, there is nothing left to "prove" except what your meaning is of the term "cross winding", which I would submit is a term you are trying to "define" rather than "proving" anything. 

It seems exactly like looking at a rock sitting on a hillside,in the same position it has been in for a thousand years, and asking someone to "prove" the rock is not rolling down the hill, calling it "roll-hilling", as though adding a new slightly undefined (therefore confusing) term somehow adds anything to the question, (or even creates a question) rather than muddying the waters just enough to make it seem like (for some, perhaps) a legitimate question.  You're taking a simple question and trying to make it incomprehensible, and doing a pretty good job of it at that.  Most people would wonder if you had lost your mind or why you had nothing better to do with your time.  That is my honest take on the question.

I say that without you FIRST "defining" your chosen term "cross winding" it makes no sense to even ask someone to "prove" something is "cross winding", let alone prove it is NOT "cross winding".  What's next, "proving" your proposed, stationary wing even exists?  I respectfully submit that your proposed wing does not exist, and that it is instead a mere figment of your imagination.  Now what?

And to fixate on my choice of words "traveling" (translation of position) versus "moving", is, once again, to take a simple question and make it an agonizing exercise in futility.  If you said the wing is not moving, not traveling, stationary, aimed directly into a headwind, then simply define your new term "cross winding" as you would, to get whatever answer you wish!  How complicated is that?  Have fun playing with words - the new words don't change the configuration you already outlined using other words.

So, step 1 would be for you to unequivocally "define" your term "cross winding" then see how your proposed configuration meets your new definition of your new term.  Still, it is nothing more than re-adjusting your definitions of words: you've already stipulated the exact configuration, so nothing new is being added by more words.
Group: AirborneWindEnergy Message: 18671 From: joe_f_90032 Date: 8/11/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

The first post that describes the "particular kite wing" for consideration of whether or not such wing is "non-cross winding" used the word "accelerator" in error; I intended "accelerometer" to be the term. Thanks for respecting this correction notice about the topic.


===========================

Doug, you have returned to an emphasis that seems to match the first post where the topic depends on a choice of definition of "cross winding" for a wing in flight.  That is, it seems you agree that the proposition will be settled when a firm definition of "cross winding" is set, understood, and applied faithfully.  So, on that premise, some effort to set a definition of "cross winding" will be continued until a consensus is reached.


Toward that effort, it seems respectful to find out just how aviation has already been using the term "cross wind" and "cross winding" for various purposes.  Care will be taken to watch for nouns, verbs, gerunds, present participles in the matter. There may be several implicit and explicit definitions in the literature; and they may not all be the same; and some poor application of definitions may occur. This preliminary effort will take some study and time; the effort may be shared by anyone interested. Unfold aviation's of the terms "cross wind" and "cross winding" and any of its hyphenated forms. Explore adjectival, noun, verb, gerund, present participle uses or abuses. Abuses should reveal some challenges. Careful precise uses of the terms may enlighten. Just because the terms have been used does not mean errors of use don't occur; that is, a found use does not thereby automatically mean the terms have been well used.


Care for frames of reference will probably play strongly for reaching consensus. Practicing identifying active frames of reference for motion discussion may help. Does a falling rock hit the earth or does the earth hit the rock? And more!   


Frames of reference? What is to be held fixed while one determines velocities of a body? The vector velocity has its scalar quantity and its direction for reading that scalar quantity speed.  If the proposed wing is stationary relative to the ground and has zero speed relative to the ground, then the ground is the frame of reference in such musings.   Differently, if the frame of reference are the particles of air in the wind, then the macro wind might be taken as fixed; then the subject wing has a non-zero velocity relative to that wind and then can be seen as moving (and traveling ?) into the wind, as the wing keeps see new packets of air during the active flight of the subject wing (even though ground trace is static). The wing would drop to the ground if the wing was not so moving through the wind in such perspective.    So, it may well matter which frame of reference is chosen to settle the topic question.


Why care? Is the caring going to affect rapid airborne wind energy development (RAD) ? Maybe yes, maybe no. I have no proof that having clarity about cross winding matters will or will not nurture RAD; but I suspect that such clarity will help some kite energy systems workers see more effective PTO opportunities in their various kite systems.  I have been uncomfortable with the various laments about what is or is not a cross winding scene or configuration; just maybe clarity will reign with consensus about the matters; then a movement toward theorems with common understanding might better flourish.


So, this topic thread is not finished; several preliminary objectives seem to be invited.  It will take some time to clear the preliminaries before consensus over a conclusion about the topic question is reached. How will the AWE community use the term "cross wind" and "cross winding" and their negatives?


Group: AirborneWindEnergy Message: 18672 From: dougselsam Date: 8/11/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Joe, I diagnose this as one more case of "Paralysis by Analysis".
Not sure if you ever hope to make any progress in AWE, but my opinion is that  you're beating your head against the wall for no good reason, not leading toward any kind of an outcome, just basically "chasing your tail".  But of course, "nobody listens to me..."

And when did it emerge that more and more, longer and longer posts on the internet constitute "progress" or even "work" toward AWE?  I see it all as an excuse to "pretend" we're doing something, while doing nothing

("Well, I AM at the computer, often used for "work", and I AM typing the letters "AWE" over and over, so aren't I "working" on "rapid development" of AWE?")

Answer: no, we long-ago stopped progress in lieu of endless musings about essentially nothing. 

"Step away from the computer..."
:)
Group: AirborneWindEnergy Message: 18673 From: benhaiemp Date: 8/12/2015
Subject: AWE TU Delft Online

     Airborne Wind Energy | TU Delft Online    

PierreB 

Group: AirborneWindEnergy Message: 18674 From: joe_f_90032 Date: 8/12/2015
Subject: Stairway to Heaven

Stairway to heaven: Fireworks artist creates stunning ladder in mid-air (VIDEO) Sky Ladder - Amazing Pyrotechnic Artwork

Sky Ladder - Amazing Pyrotechnic Artwork

https://www.youtube.com/watch?t=12&v=8szVMKGIo34

Group: AirborneWindEnergy Message: 18675 From: joe_f_90032 Date: 8/12/2015
Subject: New AWE

New AWE?   Forum future ...

Richard Feynman - 1973 Nova Interview

 

Group: AirborneWindEnergy Message: 18676 From: joe_f_90032 Date: 8/12/2015
Subject: Re: New AWE

"mystery and awe"     ~ Feynman

Sharing with those who are reaching for the frontier ...

Group: AirborneWindEnergy Message: 18677 From: joe_f_90032 Date: 8/12/2015
Subject: WO2014199407 A1

Study and discussion of:

Patent WO2014199407A1 - Kite wind energy collector

 

==============================

  Arc-to-plane cycles?

Group: AirborneWindEnergy Message: 18678 From: joe_f_90032 Date: 8/12/2015
Subject: Re: WO2014199407 A1
Apparently in the English version of the patent, "wind" shows several times as a typo where "wing" was intended.
Group: AirborneWindEnergy Message: 18679 From: joe_f_90032 Date: 8/12/2015
Subject: Re: WO2014199407 A1

Some English translation of some particular Italian words are invited from anyone. Thanks.  Select the words that look confusion In the English documents.

=====================================================================


Telling clip from one of the English language documents in file:


http://www.energykitesystems.net/PatentsAWE/WO2014199407/WO2014199407CLIP001.JPG

 

Group: AirborneWindEnergy Message: 18680 From: dougselsam Date: 8/12/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Joe your post that I am replying to does show that this is just a word game.
It would be one thing if you had some specific thing you were actually trying to figure out, and I'd be glad to help, but the very fact that you admit you don't really have a definition for "cross winding" yet you seek to "prove" a stationary wing flying like a kite is NOT "cross winding" shows you are just interested in wordplay, not any specific reality.

You're really saying "I wish to prove that this wing is not doing something that I can't even define or accurately describe".  How can you prove something when you don't even know what it is you want to prove?

Still, I think I might be able to help.
In the parlance of AWE, crosswind travel refers to working surfaces harvesting kinetic energy from the flow of wind by moving perpendicular to that wind.  Energy is thereby harvested, according to the formula E = F x D  (Energy = Force x Distance traveled).  If there is no distance traveled, there is no ENERGY harvested, so a stationary wing is not under consideration for "crosswind travel" (or "cross winding") in the context of airborne wind ENERGY..

The wing WOULD deflect air downward, so some might posit that there is some component "crossing" the wind (vertically), if only by the camber and angle of attack of the wing changing the direction of a portion of the wind, but that would be wrong, since our topic is airborne wind ENERGY, and ENERGY is only produced by MOVEMENT (in our context) so a stationary wing will not produce energy, and so no, a stationary wing is not "crosswinding" in the context of airborne wind ENERGY, but instead, it is stationary, not even wiggling, as you stipulated.
Group: AirborneWindEnergy Message: 18681 From: Rod Read Date: 8/13/2015
Subject: Massive Depower

Which AWE system has the most massive de-power available whilst maintaining control and power output function?

A large de-power control range will be a crucial factor of successful AWE. (In my opinion)

Competent handling of the full range of speed and load scenarios in a generation system or any airborne system is of paramount importance.

How does any particular AWE device adjust itself to transition  
full power - de-power - power - de-power... in the full range of winds, loads, under fault scenarios?

Yo-yo teams have thoroughly analysed standard kite performance. The parameters allow for adjustment within a set of operational conditions to be specified. They have a range of de-power and operation much as any surf kite. (job done? Well they're still quite inefficient.) ... Many x-surf kite teams are moving toward rigid wing.

Rigid wings have well defined performance characteristics and a larger range of de-power in kited mode. (The power up is much greater and the smooth profile at 0 or -ve  AoA allows low resistance slip through the air. (de-power)) There is however the problem of scale. As they get bigger rigid wings will become prohibitively heavier and not accelerate so well.

There are other analogous sail and kite methods of de-power. Single point bridle lift kites automatically adjust their AoA dependant on wind strength. Masted sails often twist out at the tip when over powered. Furling and reefing sails effectively lessens their area. Shortening kite lines. ( brings a kite to down slower wind, reduces the size of the wind window, cuts line drag and makes a kite better upwind) Elasticated bridling and C-kite bridle balanced flexing reduce overloading by frontal projection changes. Single skin kites can deform to de-power in many modes. Plane and bird wing-tips flex, feather, fold and flutter...

My question has to be... How massive can the de-power of a Daisy (lift line towered tensile ring rotary system) be? By how many modes can this de-power be achieved?
Can the driving wings (fins) AoA be sheeted in and out? yes.
From the ground or power controlled from the bridle point, or elastically from the bridling? all 3.
Can the bank angle of the fins be sheeted up or down? yes.
From the ground or power controlled from the bridle point, or elastically from the bridling? all 3.
Could the fins be reefed back fully onto a ring? Yes. Many kites and sails already recover and relaunch this way. (Thinking flattens type cam inducing leading edge...mmmm)
Could the fins conceivably be released to fly further out from the ring to maintain top speed L/D in higher upper wind speed for useful traction whilst keeping a constant rotary speed with lower ring kites? yes.
From a ground controller? yes. wow.
Are there other ways to actively change ring diameters? Yes. With modular or inter sliding fin and ring bodies.
Can the number of rings on a lifted line be increased and decreased whilst the system is powering? I believe so with good ground based robotics.
Can rigid wings be used as the fins of a Daisy system? Yes. As long as they are secure, monitored and controllable... Why not until you reach scaling limits? However I bet some sort of asymmetric thermoplastic single skin semi rigid laminate hybrid will likely be a best compromise. mmmm.
Will it still work when various parts of the system break? I believe so as I've already seen in practice.

How will your proposed systems handle massive de-power and power up?
Can a single kite handle this as smoothly as a kite array?


Group: AirborneWindEnergy Message: 18682 From: Rod Read Date: 8/13/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
"Cross wind" references the change of location of a body in the frame perpendicular to the wind flow direction at a stated point.

What anyone defines as forward on an asymmetric kite might not point directly into oncoming wind as the kite stays in one place. The wind may go across the wing... yet the wing is not going across the wind.

When wind flow is deformed around a kite surface and vortexes are shed...(Is the wind cross winding?)

Deflection of air mass effects and lift through an apparent wind are fairly closely described already.

I'll know more once I've gone through the Delft AWE course hopefully.

Rod Read

Windswept and Interesting Limited
15a Aiginis
Isle of Lewis
UK
HS2 0PB

07899057227
01851 870878


Group: AirborneWindEnergy Message: 18683 From: benhaiemp Date: 8/13/2015
Subject: Re: Massive Depower

Complete depower for Rotating Reeling  : holding  only by the central rope, peripheral ropes escaping, kite turning around. But Daisy configuration is different at least by ladder torque.


From http://www.awelabs.com/wp-content/uploads/Rotary-Lift-AWES.pdf :

" In the case r=R/3 (the distance between the blades equals the blade span)*


δ≈.48



Thus, a blade in this rotary wing is about two times less efficient than the same blade in the straight flying wing" .

So this is an easy way to calculate efficiency of rotating kite: by Loyd's formula x cosine cubed x 0.5. For rigid or soft blades (in a single wing configuration as Parotor).




PierreB

* both Parotor and Daisy are concerned

Rotating Reeling 


Group: AirborneWindEnergy Message: 18684 From: Rod Read Date: 8/13/2015
Subject: Re: Massive Depower
It's a great article link thanks Pierre.
You have a well thought through design Pierre.
Hopefully the rotating reeling system allows massive generation scaling.
Can't wait to find out for definite.

I agree that ladder de-power on a Daisy system is different and awkward looking ... However it still allows for de-power much as a kite surf bar does...
However I have proposed for a long time that a Daisy should have ring to ring transfer of torque over lift line will allow much greater control and reliability.

The analysis by Leo in the linked article is for traction (line pulling effects only as output)
One of the many things I love about Daisy is that it uses the traction power usefully to transmit the rotary power.

Rod Read

Windswept and Interesting Limited
15a Aiginis
Isle of Lewis
UK
HS2 0PB

07899057227
01851 870878


Group: AirborneWindEnergy Message: 18685 From: dougselsam Date: 8/13/2015
Subject: Inflatable tower - farfetched?
Canadian firm patents inflatable space elevator


Group: AirborneWindEnergy Message: 18686 From: joe_f_90032 Date: 8/13/2015
Subject: Re: Inflatable tower - farfetched?
Patent US9085897 - Space elevator

 Its priority date: Feb. 21, 2007


Group: AirborneWindEnergy Message: 18687 From: joe_f_90032 Date: 8/13/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Good continuation, Doug. 
Thanks.
1. I am not yet buying into the relegation of "just" a "word game," while agreeing that the game herein does use words. The practical application space of clarity on the matter may be extensive.   I won't sell such short at this time.

2. The task of respecting "cross wind" and "cross winding" and their hyphenated forms and negatives within aviation has yet to be comprehensively placed on the table.  The objective of such preliminary work would be to join with any found strong and clear use as some definition is brought into the proof process. In the literature there are indications that confusions occur.  Even your wrestling with the wing's interaction causing there to be a deflection of the wind crossing the incoming stream begins to show that some careful work may have to be done. Rod's remark in topic above also indicates that work in this preliminary area may be fruitful; though, it is my guess that Roland S. course will not settle the matter at hand.

3. For clarity, you construction a quote that was rhetorical that a reader may or may not see as not my quote, but your construction of a quote that implies your interpretation of what I might be saying; I don't own the construction, so I make this notice. For convenience, I repeat your construction: "You're really saying "I wish to prove that this wing is not doing something that I can't even define or accurately describe". "    Differently, I contest that the topic is a challenge that may or may not be met; indeed, an answer to the challenge of topic command might be by someone: "A proof is not possible for the following reason: ________."  And the reason might be a proof of undecidability of the matter; or the reason might be a proof of cross-winding for the given scene. Hence, the outcome for me might be opposite from what is implied in the constructed rhetorical quote. Time may tell; the project is not complete.  So, reader, I was not "really" saying what the constructed rhetorical quote infers.  A topic challenge is placed; how will be challenge be met?

4. Thanks for the paragraphs on harvesting energy.   Yet, even in your welcomed paragraphs, there seems to be a struggle with the energy harvested to keep the subject wing aloft. The energy to keep the wing aloft in its position gets harvested from the kinetic energy of the faced wind; "faced wind" may need some attention for the challenge, as the wind very close to the wing of subject is different from the wind far upwind of the wing.

5. If the wing of topic is shown to be cross winding in one sense and non-cross winding in another sense, then the wing would have in its unified universe the quality of topic without contradiction. Such very well may depend on just exactly what definitions are brought to the game.

May your other good works be well attended to and brought to fruition,
~ JoeF



Group: AirborneWindEnergy Message: 18688 From: benhaiemp Date: 8/13/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Some questions: is "crosswind" implying  a movement of the wing with regard to the wind? And the contrary for"cross wind" (a movement of the wind with regard to the wing) ?

If yes as eventual (maybe not correct) example, the hollowed out center of a rotating body could be seen as a part cross winding, while the tip of wings would work crosswind.

Now generally in AWE universities or companies "crosswind kite power" does not appoint rotating kite as such. I evoked this question. So Joe's topic is welcomed for trying to solve it at least in a first simplified analysis.



PierreB

Group: AirborneWindEnergy Message: 18689 From: benhaiemp Date: 8/13/2015
Subject: Rotating Reeling : asking for simulation

Thanks Rod (see Massive Depower) . Now I have to prepare full paper for AWEC2015 TU Delft .  I am in contact with some engineers but they will be available in autumn (current deadline for paper is mid September, so perhaps too soon for me).


For the moment I have an equation for kinematics . Equations for forces will perhaps come. Hoping including aerodynamics. Indeed as generators are settled in winches, as the conversion is on upwind part, the center of pressure is not more in the center of parachute as hub, but is moved towards the upwind side; on the other hand such a moving of center of pressure is compensated by the wing going also upwind and generating more pressure. So deeper analysis and active control on hangers of soft power blades will be required for a large unity.

After it towards some action for a real prototype.


Concerning traction of rotating wing (I put again the link: http://www.awelabs.com/wp-content/uploads/Rotary-Lift-AWES.pdf ) you raise an important concern. Indeed LeoG's paper considers traction. But Loyd's formula works for reeling (traction) as well as for what he names "drag"  because of slowing down by onboard propellers (i.e. flygen or his patented transmission).

For rotating wings as Daisy and Parotor (rotating reeling) I think both traction and torque are involved. A simulation would be welcomed.

   

PierreB


Rotating Reeling


Group: AirborneWindEnergy Message: 18690 From: Joe Faust Date: 8/14/2015
Subject: Calm-or-Low Wind Arch Kite Flying
Calm-or-Low Wind Arch Kite Flying
Two or more moving anchors per arch kite system (series of arches may follow paths). Bases may be land, water, aerialized cable, or a combination of such bases. Methods involved may be used on earth or in space or on other planets in air, water, gases, atmospheres, liquids, or photonic streams. Methods involved may be used in industrial processes.
    • Parallel path (use: two sets of walking or running persons, two separated railed tugs, two vehicles on roads, two vessels on water, or use two aircraft) [more than two tugs in an operation may be used]
      • Cross-ocean
      • Cross vast land
      • Reversing pattern (tow one way and then later reverse directions)
      • Indoor spaces
    • Hybrid snake path
      • Cross-ocean
      • Cross vast land
      • Reversing pattern (tow one way and then later reverse directions)

    • Simple circle path (center of arch stays calm while outer wings fly). Central region could be land or water or a mix of land and water. The central region could be occupied by any compatible activity or habitation.

    • Ring flying (two arch anchors are in distinct non-zero diameter circular paths)
Practical purposes of the Calm-or-Low Wind Arch Kite Flying technology: 
    • Transportation 
    • Moving goods and materials
    • Moving very-large objects
    • Entertainment
    • Recreation
    • Sport 
    • Race competition
    • Art
    • Painting
    • Application of seeds or seedlings
    • Crop dusting
    • Environment cleaning
    • Ocean cleaning
    • Bird scaring away from crops
    • Rescue of persons, animals, or vehicles
    • Fire fighting
    • Crop treating
    • Harvesting crops
    • Herding animals
    • Landscaping
    • Photography
    • Pest eradication
    • Move toxic gases from a scene
    • ... and other applications
Calm-or-Low Wind Arch Kite Flying technology is managed and licensed by kPower, Inc. 
The methods, tools, and systems may be applied to air and water media; and the the same for non-calm windy conditions. Modify parts and control of the kite arch system to meet the anticipated wind and weather conditions needed for a particular application. 

Negotiate with kPower, Inc. for research uses, commercial applications, scientific applications, or any other use of the technology. 
~ Joe Faust    
Group: AirborneWindEnergy Message: 18691 From: Joe Faust Date: 8/14/2015
Subject: Re: Calm-or-Low Wind Arch Kite Flying
One person or one tug of any sort may base the bridling of the constrained (way, rail, cable, ...) two anchors of an arch kite in calm or wind for above reasons and purposes. And notice that a series of such arch kites may be prime moved by the multiple or single tugs (or in reverse: generators and other power takeoff PTOs).  And the same systems may pull a single object (vessel, craft, hull, person, generator set, etc.) by conversion of ambient winds.  These and other means in the spirit of the disclosure are included up to such that one skilled in the attending arts would readily see as matching the technology. 
    kPower, Inc.
~ Joe Faust
Group: AirborneWindEnergy Message: 18692 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Perhaps a short moment for again clarifying:

The topic is set in a command voice, not a wish-by-me voice. A responder could rightly attempt to show that the command has no possible outcome.  I do not think that I set forward a personal wish for the outcome to be positive or negative.  


If someone wrote: "Joe said he wanted to prove a given configuration did not have the characteristics of a word which he admitted he could not define."   ... then I would be moved to clarify my position for the topic, which I do now against such declaration over my wants and admissions.  

1. I did not say I wanted to prove a given configuration, etc.   What I opened the root topic with was something in a command voice: "Prove a particular wing as non-cross winding."

2. As to "cross winding" there has been some preliminaries that are still not done; working on clarifying what definitions would go into a given proof is common proof practice.    I never "admitted" inability to define the term "cross winding";  the ability was and is present; and that ability is being executed through a defining process that includes yet finding robustly how the term has been used in aviation. Proofs will have well-defined key terms in them. When the term does get well defined by my ability and the ability of other definers, then that part of the proof process will be available.

Group: AirborneWindEnergy Message: 18693 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
OK well here's how I see it:
Under consideration is a very simple and well-defined scenario, somewhat like a "thought experiment", except there is no question about this scenario actually being asked.  There's no question about the configuration, no question as to the movement of the wing, the wind, nor the tether, nor the ground, nor energy produced.  The ONLY question is regarding word definitions.  "Can we "prove" it is "not cross winding" (not described by a certain phrase).
And the clincher that makes that question meaningless is that you can;t define what that phrase means.  That is what I mean by "chasing your tail". 

To me, your description "proves" it is not "cross winding" since it is stationary.  Otherwise, just provide whatever DEFINITION of "cross winding" you desire, to get any answer you wish!  Your answer depends ONLY on your definition of that word.  So the question you are really asking is "what is the definition of cross winding?" which I see as a) using a phrase in an unusual way that seems to imply uncertainty, and b) using this artificially-injected uncertainty to pretend a well-defined and simple configuration is suddenly incomprehensible and mysterious.  Weird and unproductive focus in my opinion.

Let me be clear here: Words are only useful when they describe reality. To have a forest of interrelated words and continually adjust the meaning of some words in relation to others in an endless quest to "redefine" words to get to some unknown goal of "proving" some relationship between these words gets nowhere.  It doesn't affect the actual configuration, and gives no answers that affect any outcome.  If you HAD some unknown aspect of the described configuration you were actually trying to learn something about, some feature or fact of the actual physical configuration that you were trying to discover, that would be one thing.  But instead you have pretty-much completely described an idealized configuration, and your only goal at that point seems to be some sort of effort to "define" the word(s) "cross winding".  You might as well describe the exact same configuration and ask the question: "Can we prove the wing is not colored blue?". 

If I'm just not seeing what you mean, please tell me what answer could emerge that would change anything, given your described configuration?  I mean, what is your actual goal?  What is it you don't understand about your proposed, idealized configuration?  If there IS a question, can you put the question some other, that does not use the phrase "cross winding"?  :)
Group: AirborneWindEnergy Message: 18694 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Pierre, the term "crosswind" in "kite-power" is to distinguish, in the kite-flyer's mind, movement of the kite ACROSS the wind, as opposed to just being blown DOWNWIND (just pulling the string).  It's the equivalent of the distinction in wind energy between a "lift" device and a "drag" device.  The term was introduced to emphasize a beginner aspect of wind energy to people who had no concept about wind energy.  It's the beginning of a the most basic education in wind energy, for kite-flyers. 

There's no need to beat a definition of the term to death, its use is just to get people without any background in wind energy to the first step of realizing how to collect wind energy efficiently, as opposed to say a Magenn, that just uses the "push" of the wind to drive working surfaces downwind at less than the wind speed (inefficient). 

Like the terms "lift device" and "drag device", no pretense should be made that either term even HAS an EXACT definition, since that leads to endless analysis to the point of trying to define the movement of every molecule in a complex situation that changes from moment to micro-moment.  Such terms form more of a "rule of thumb" vocabulary of approximation.  An example would be a farm water-pumping windmill:  Most wind turbine experts agree that it has characteristics of both a lift device and a drag device, being a borderline case.  Most experts would frown on an undue fixation on trying to "prove" it was a lift device or a drag device at that point.  It would be seen as a waste of time: the turbine is what it is, and you;d only be adjusting the definitions of the words "lift device" and "drag device".

But really, where I see an illogical question in this discussion, is to cite a mere word (or phrase) that one cannot even provide a definition for, then ask to use that undefined word in a "proof".  A word without a definition is merely a collection of letters.

What Joe is really asking is: "Can you prove the action of stationary wing, flying like a kite, in a steady wind, is NOT described by a series of letters C, R, O, S, S, space W, I, N, D, I, N, G ?"  Without defining what that series of letters stands for, there IS NO ANSWER.  The ONLY answer is to define what MEANING that series of letters has (define the word), then the answer would fall out like an apple falling from a tree.

That is why I say, most of these questions involve nothing but the definition, and attempted re-definition, of words.
Group: AirborneWindEnergy Message: 18695 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Joe your fixation on word definitions has now veered toward nitpicking my attempt to summarize, colloquially, your original question, now analyzing my words.  "Joe wants" or whatever.  Please get beyond trying to dissect the message word-by-word to find a flaw, and just grasp the general theme of what I'm trying to say.  The essence of what I'm trying to say is "What are YOU trying to say?".  I still have no idea what you are trying to say (ask) and I'm not seeing any evidence that you, yourself, know what you are trying to say (ask). 

What is it you really want to know?  Can you ask your question in different words, so it is not dependent on the term "cross winding"?  Surely, if you actually HAVE a question, it could be phrased in a different way, without using an undefined term!  What is the unknown here, (other than the definition of a term)?  Just tell me what it is you are really trying to figure out about your proposed configuration.  :)
Group: AirborneWindEnergy Message: 18696 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Super, Doug, thanks for your time and care to state how you see it. Your effort won't go in vain, I intend. Your several steps bring up some important parts of some proof processes and tactics. Problem solving has many tools available; and as you urge, some of those tools may come into play in this proof project.


You mention "well-defined scenario" which may be a sound appraisal or not. There has been an effort to present a scenario, but the presentation may well be not well-defined; perhaps some work is still needed to bring the scene up more clearly.  I am not yet fully confident that the scene is "well-defined", yet I accept that you see the matter as set with a "well-defined scenario."    It would be grand if the scenario was well-defined; it might take some effort to establish that the scenario is or is not well defined.  I do not quit just because there are such challenges. The gut cause of the starting the topic just might be important to part of AWE's RAD.


As you unfolded how you see the matter, you mentioned that "there is no question about" "energy produced". Yet in discussion we do have some question about energy produced in the scenario; it was reviewed that some energy must be produced and used to keep wing where describe.  With such, I would hold that there remains some question about energy produced in the scene.  Pending the outcome of clarifying the energy matter, suppose it was agreed that energy was produced from the wind's interaction with the described wing; then we see the topic command and perhaps wonder upon such: Did the energy production arrive from cross-winding or non-cross winding?


Your way of seeing the matter let you posit a claim that may not be fact: "is that you can't define what the phrase means."    I hold that I can define the phrase; and it is evident that having a definition of the phrase will be core to facing the topic command.  It is also evident that the defining of the phrase is in committee work by any and all who wish to work on that committee; to face the topic command, a definition will be at hand for provers to use to form various proofs in the affirmative or in the negative.  I can define the phrase to have a resonating fit with aviation culture or not; the effort is to use the ability to define in order to have a definition that will meet consensus in the aviation community and be applicable to the topic scene. Feeding the ability to define will be using the results of the committee's research and summary.  You and others are welcome to propose definitions; I notice that Rod had a go on this matter; his effort needs to be brought into the committee with care and respect.   And, Doug, your proposals for definition of the phrase are welcome also into the committee's work.  I will be forming some proposals also. Ultimately, a definition for firming the preliminaries for this topic command will be posted. In whatever way some of us thought the topic command could be resolved very quickly, the unfolding non-quickly flow may seem disappointing; but I invite looking at the gems and roses along the project way; Pierre made some expression toward the support of the topic that seems to fit this invitation to gain value from the topic's struggles.


Doug, I invite you to distinguish between a stage of non-clarity and the perhaps different matter of continually changing or adjusting the meaning of some words in relation to others.  I hear your lament and guess. But I am seeing a neat pause to obtain a fixed definition of "cross winding" and "non-cross winding" for the project. The approach to the entry for project has apparent non-clear challenges; reaching for the clear definition to be used in the proof process is, I offer, far different from what you lament about continual adjusting.   No essential adjustment will be permitted for a fixed proof process; essential adjustment could simply cause a full second proof process distinct from the intended project.  Second projects could be fine, but distinction would be the respectful thing to uphold.   I am not wishing the topic command come out positive or negative or undecidable; since you brought up my wish sphere, I'll state it: I wish to face the command of topic soundly with the hope that a tool will become available for the AWES community to use as we face fulfilling practical tasks with kite energy systems or other AWES.   To have clarity over the topic command is estimated by me to have a productive flowering.


The scenario wing is not stationary with respect to the wind's particles. The distance between the wind's particles and the scenario wing is changing; the angular reference of wing parts and wind parts are changing. Heat and noise and lift and drag indicate that energy is being harvested and transformed in the scene. The wing interrupts the horizontal paths of the wind's particles; a resultant involves the some of the wind's particles to be on changed trajectories; accelerations are involved; it seems the wing is crossing the wind and the result of the crossing is a spectrum of results: heat, noise, lift, drag, new paths for wind particles. Lively scene, yet the wing stays put relative to the ground.


Your last paragraph demonstrates a good problem-solving tactics. Rephrasing, stating goals, identifying what may not be known, etc.   We have been generating some of such.  In rephrasing, one will have the challenge to assure equivalency. An equivalent rephrase of the topic command is not jumping into my mind just yet. Any proposed rephrase would be on the discernment hot seat to show equivalency. If I get a rephrase, I'll post the proposal.    As to what is not known, I offer that it is not yet known robustly what the aviation community means by "cross winding" on evidence that confusion is expressed here and there.


Best,

  ~ Joe F.

Group: AirborneWindEnergy Message: 18697 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
Joe:  I'd like to see your question re-phrased WITHOUT using the term "cross winding", "crosswinding" or "cross-winding".  Can you please restate the question without using these terms?
Group: AirborneWindEnergy Message: 18698 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

While you were typing the below, I had been facing some of such and typing at the same time, see posted.


Of course, I have respected your freedom to summarize and put forward your points. Indeed, I treasure your points and derive value for the project by your inputs.  Thanks again.   


It is evident that you struggle with my inputs also.  I am not clear if you are deriving any value from my inputs or not.


Let me assure you that the topic command is not a "fixation" on "word definitions", but a matter of whether or not a scenario has going "non-cross winding".  There is a implied given of a definition for cross-winding and non-cross winding; that the "given" was not explicitly given yet does not alter the topic.  It appears that the "given" will have to become explicit to forward the project.   Such giving is underway as described in my former post; meanwhile, you may explicitly supply a definition and then proceed with a proof; if your supplied definition does not match someone else's supply for the "given" then there could be a contest about equivalency of topic, which would be fine, as AWE may be advance at many fronts.


Your request that I try not to dissect what you offer is most challenging to me.  I aim to understand posters' participation. One tactic is to dissect feed back for checking to see if I am understanding the offered perspective. Your lament teases me to think that my understanding your perspective may not be important to you, but maybe you want me to just flat believe whatever you offer without understanding what you offer; if I sense a challenge or confusion or possible contradiction or possible inadequacy toward the project ... or some facet that could enrich the project ... in your offer, then I tend to highlight the facet to see such in fresh lights. Agreements are easy and supplied; it is when a disagreement is present that some work is invited; it is not a matter of "nitpicking" and "find a flaw", but a matter of positively understanding offers, common ground, differences. Correctable statements are ores from goldmines; clearing correctable statement helps to find more common ground or gold, I offer. If you think or feel something enough to make a statement in the process, then perhaps that something has some importance to play.  I suspect that in aviation literature some feelings combined with rash beliefs has produced some fuzzy and sometimes confused holding of cross winding matters; studying cross wind landing literature will bare some of the struggles and confusion. In AWE there seems to be a discomfort about cross winding matters.   If I reach for clarity over some of your statements that are brought in the topic process, but such statements prove to be non essential to the final proof offers, then still some lateral clarity could get on record for use in other topics. 


Here is what I am really trying to figure out about the configuration:  I want to know if the configuration is non-cross winding (or is cross winding).     It appears that you have a theorem that always there are at least two ways to phrase a question.   If such is fact that such a theorem applies, then any of us is free to seek and maybe find an equivalent phrasing of the topic question. Each proposed rephrasing would need to be equivalent to the topic command; proving the equivalency would be a neat project in itself; then after proving the equivalency, the topic task would remain; but in problem solving, after equivalency is shown, the new equivalent might somehow seem easier to resolve.   I have seen many times the touting of what you seem to have as a theorem, and generally I buy into the flow by assent, but I have not seen a proof that every question has at least two equivalent ways; but a proof might not be too far off: French and English translations, if shown to be equivalent could be an easy proof; but I suspect we are asking for more than just language phrasings. Until proven otherwise, I flow by assent with you that there is a equivalent rephrasing for the topic command; I have not knowingly put up such yet; anyone is welcome to offer such. Once a consensus on a definition of "non-cross winding" is at hand, then rephrasing of the topic command would be easy; and equivalency would be simple by simply using the definition.  Again, committee work.


Best to you and yours,

 ~ Joe F.





---In AirborneWindEnergy@yahoogroups.com, <dougselsam@gmail.com
Group: AirborneWindEnergy Message: 18699 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

As just posted, I will supply a second phrasing when such comes to me and I have shown equivalency of the second phrasing. Meanwhile, you or others are welcome to put up a rephrasing and hopefully a proof of equivalency.  Yet still, one may continue with the first phrasing.   Both processes may go in parallel.


Best,

  Joe F

Group: AirborneWindEnergy Message: 18700 From: benhaiemp Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Doug, my main idea, for years, is the maximisation of space. 

Generally "crosswind kite power"  terms appoint a kite wholly moving by a path like Airborne Wind Energy 

or like Advanced Controls Enable Airborne Wind Power Generation | RTC Magazine 

but not a rotating wing as lift (TSR several times wind speed) or drag (TSR < or = wind speed) device; however it is!

You often hint in the lack of relevance "crosswind kite power" terms as used by universities, that regarding the "real world" of wind energy for which crosswind is already a reality.

But I observe that you are not understood enough since new teams repeat the same, OR there is another thing to consider: in my opinion, it is in the (obvious but important to keep in mind) difference between:

  1. not flying wind system
  2. flying wind system (implying analysis of flying and producing)

then: 

  1. a path controlled by computer as on the two examples, and
  2. the forced path  by construction for rotating wing (and also current HAWT).

In 1.  as I often wrote , flight requirements result excess of used space regarding useful swept area (by itself and also by long moving tether).

In 2.  in spite of a lower efficiency (1/2) by wing area, one of positive features is the forced path, allowing an easier control, one other being in the possibility of maximisation of space. 

In temporary conclusion I think stationary-tilted-rotating-wing will be AWES basis configuration as stationary-horizontal-axis-three-bladed is the current basis configuration of existing ground-based wind turbines.

And more precise terms can allow a better understanding, so better purposes in R&D.


PierreB

 

Rotating Reeling


Group: AirborneWindEnergy Message: 18701 From: dougselsam Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.
OK here is my answer:
The wing, flying motionless, like a kite, in a steady, horizontal wind, not wiggling, not wavering, not wobbling, must deflect a portion of that wind downward, in order to stay aloft against its won weight and against any additional downward pull by the tether.  Since you have defined the wing as motionless, then there are two possibilities:
1) If you DEFINE "crosswinding" as traveling across the wind, then, no, the wing is not traveling across the wind, since it is not traveling.
2) If you define "crosswinding" as pushing the wind in any direction other than its original direction, then yes, the wing IS crosswinding.

It comes down to "what is your definition of crosswinding?"  Define it the way you want, to get the answer you want.

And if you try to say the frame of reference is indeterminate, I say yes it is determined (by you), it is the ground.  The ground is the frame of reference in this question because you've defined the wing as motionless with respect to the ground, being tethered to the ground, the wind itself has been defined relative to the ground, and in AWE, the energy is utilized at the ground.

With regard to using aviation terminology to find a magic definition, good luck with that, since the aviation version would be referring to "crosswinds" which deviate horizontally from the direction of travel, forcing the airplane into "crabbing" or flying in a sideways-skewed (yaw) orientation to stay aligned with the runway during landing.  Your proposed scenario involves a vertical deflection, which in aviation would fall into the parlance of "pitch", "updraft","downdraft", and "vertical deflection", not "crosswind".

Would an airplane parked on a runway in a crosswind be "crosswinding"?  Good luck.  It would only depend on what YOU choose the definition of "crosswinding" to be at that particular moment.  The entire exercise is really just an attempt to define a word, not to answer anything not already known about the described configuration.  What is the unknown?  You just keep using that word "crosswinding"  The only unknown is the definition of that word.  Everything else has been defined.

What amazes me is how many words we can both use to say essentially nothing.  Define your chosen word, "crosswinding" and you will have your answer.  The way I see it, there's nothing to "prove", just a question of what you mean by the word "crosswinding".  So, figure out what you WANT the word to mean, then the answer to your question will emerge. 

You already know the wing must be deflecting the wind downward, so there you have it!  Call it whatever you want!  I'm sure if you asked a pilot, he'd say "No, it is not "crosswinding", it is flying straight and level, directly into a headwind" , so aviation is not going to capture what you seem to be looking for.  Again, define the word the way you see fit, then take your resulting answer, and be done with it.  "Step away from the computer..."  :)
Group: AirborneWindEnergy Message: 18702 From: joe_f_90032 Date: 8/14/2015
Subject: Re: Prove a particular kited wing as non-cross winding.

Thanks, Pierre, for some inputs on the project. Your questions and statements show to me that the committee work over just what usages are will become fruitful. The questions will spawn some answering, I bet. Verifying your question and the spellings will be a step to appreciate your questions, I think.


Then your statements invite work for the committee on the terms.  A gathering of references for what universities and companies are doing with the terms forms a sector of aviation's massage of the terms.  My first blush is your use of "generally" which has me not know securely; just how many exceptions there are may eat away at the "generally" dimension to the statement. Just what is a "rotating kite" in this context  may not be settled. Near the beginning of the forum there was a struggle over whether a single-tethered real kited wing was a turbine or not; I came away with "turbine" ... yes. Others may not have seen the same; in such light, I had that that same turbine was thus a rotating kite, albeit not as robustly starkly rotating as what others had in mind.  The Roto-kite having dancing two wings coupled came into discussions also. Grabbing elongated figure-8 paths and forgetting the cross winding involved in non-figure-8 kite systems while rashly calling one cross winding and the other not so by neglect, would tend, I think, to finally be a cause for confusion when technical descriptions are wanted. A world-level voting for classes and definition of classes has not been done. Still, when such voting may occur, the mechanical realities will not be washed away, but only a facilitation will have been constructed in order to achieve some objective.   The topic command using the word "prove" may invite concentration on the mechanics involved with as little dependency on voting or "generally" as possible, albeit a consensus will be needed to set distinctions; and thus the committee work on the definition of "cross winding" and its negative.  


Toward your first question, I've some preliminary response. If the wind is changing related position with the wing, then equivalently the wing is changing related position with the wind. Else: Let the ground be the fixed frame of reference; have the wing be unchanging in position relative to the ground; then a wind is seen as moving about the wing.   Differently, take the wind as the fixed frame of reference; then the wing is moving into and about the wind.  Full exploration of frames of reference would probably allow a useful source of definitions along the lines as might be suggested by your paragraph.   Working this out may joyfully join the committee work.

Soon,

   Joe F.


===============================================
---In AirborneWindEnergy@yahoogroups.com, <pierre.benhaiem@orange.fr