Messages in AirborneWindEnergy group.                          AWES 23025 to 23074 Page 353 of 440.
Group: AirborneWindEnergy Message: 23025 From: joe_f_90032 Date: 9/18/2017
Subject: Re: Minesto news : 2017 summer new hires

Group: AirborneWindEnergy Message: 23026 From: Joe Faust Date: 9/19/2017
Subject: ​Alphabet Remains Committed to Makani Wind, Says Startup

Group: AirborneWindEnergy Message: 23027 From: dave santos Date: 9/19/2017
Subject: Re: [AWES] ​Alphabet Remains Committed to Makani Wind, Says Startu

Group: AirborneWindEnergy Message: 23028 From: joe_f_90032 Date: 9/20/2017
Subject: Market report regarding some AWE matters. New or old author?

Group: AirborneWindEnergy Message: 23029 From: dave santos Date: 9/20/2017
Subject: Re: Market report regarding some AWE matters. New or old author?

Group: AirborneWindEnergy Message: 23030 From: dave santos Date: 9/21/2017
Subject: Chanute's Lessons to AWE

Group: AirborneWindEnergy Message: 23031 From: joe_f_90032 Date: 9/22/2017
Subject: Re: WindLift Update

Group: AirborneWindEnergy Message: 23032 From: joe_f_90032 Date: 9/24/2017
Subject: Generating interest

Group: AirborneWindEnergy Message: 23033 From: dave santos Date: 9/24/2017
Subject: Re: Generating interest

Group: AirborneWindEnergy Message: 23034 From: joe_f_90032 Date: 9/24/2017
Subject: Re: Generating interest

Group: AirborneWindEnergy Message: 23035 From: joe_f_90032 Date: 9/24/2017
Subject: Re: Generating interest

Group: AirborneWindEnergy Message: 23036 From: dave santos Date: 9/25/2017
Subject: The necessity and peril of small-scale AWES experiments

Group: AirborneWindEnergy Message: 23037 From: dave santos Date: 9/25/2017
Subject: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23038 From: Peter A. Sharp Date: 9/25/2017
Subject: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23039 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23040 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23041 From: Peter A. Sharp Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23042 From: Peter A. Sharp Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23043 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23044 From: dave santos Date: 9/26/2017
Subject: Second Test Session of Looping-Foil on Drive-Loop

Group: AirborneWindEnergy Message: 23045 From: Peter A. Sharp Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23046 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23047 From: dave santos Date: 9/26/2017
Subject: AWEC 2017 buildup

Group: AirborneWindEnergy Message: 23048 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23049 From: dave santos Date: 9/27/2017
Subject: Octave Chanute, "Father of Aviation"

Group: AirborneWindEnergy Message: 23050 From: Peter A. Sharp Date: 9/27/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23051 From: dave santos Date: 9/28/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Group: AirborneWindEnergy Message: 23052 From: dave santos Date: 10/2/2017
Subject: 2017 AWE R&D on-track by Critical Path Analysis

Group: AirborneWindEnergy Message: 23053 From: dave santos Date: 10/2/2017
Subject: A bounty of new work- AWEC2017 Book of Abstracts

Group: AirborneWindEnergy Message: 23054 From: joe_f_90032 Date: 10/3/2017
Subject: Fusing Kite and Tether into one Unit

Group: AirborneWindEnergy Message: 23055 From: dave santos Date: 10/3/2017
Subject: Re: Fusing Kite and Tether into one Unit

Group: AirborneWindEnergy Message: 23056 From: joe_f_90032 Date: 10/3/2017
Subject: Kitepower's "Model A" ground station

Group: AirborneWindEnergy Message: 23057 From: joe_f_90032 Date: 10/3/2017
Subject: Re: Kitepower's "Model A" ground station

Group: AirborneWindEnergy Message: 23058 From: joe_f_90032 Date: 10/3/2017
Subject: Hiroshi Okubo

Group: AirborneWindEnergy Message: 23059 From: joe_f_90032 Date: 10/3/2017
Subject: Re: Hiroshi Okubo

Group: AirborneWindEnergy Message: 23060 From: joe_f_90032 Date: 10/3/2017
Subject: Re: Hiroshi Okubo

Group: AirborneWindEnergy Message: 23061 From: dave santos Date: 10/3/2017
Subject: Re: Kitepower's "Model A" ground station

Group: AirborneWindEnergy Message: 23062 From: joe_f_90032 Date: 10/3/2017
Subject: Re: Japanese ~VAWT under Kite Train AWES video

Group: AirborneWindEnergy Message: 23063 From: joe_f_90032 Date: 10/3/2017
Subject: Re: [AWES] ​Alphabet Remains Comm itted to Makani Wind, Says Start

Group: AirborneWindEnergy Message: 23064 From: joe_f_90032 Date: 10/3/2017
Subject: Re: [AWES] ​Alphabet Remains Comm itted to Makani Wind, Says Star

Group: AirborneWindEnergy Message: 23065 From: joe_f_90032 Date: 10/3/2017
Subject: Lista, Norway : Lista Airborne Wind Energy Center AS

Group: AirborneWindEnergy Message: 23066 From: joe_f_90032 Date: 10/3/2017
Subject: Unmanned Valley Valkenburg (UVV) in Netherlands

Group: AirborneWindEnergy Message: 23067 From: joe_f_90032 Date: 10/3/2017
Subject: Airborne Wind Europe

Group: AirborneWindEnergy Message: 23068 From: joe_f_90032 Date: 10/3/2017
Subject: Airborne Wind Earth

Group: AirborneWindEnergy Message: 23069 From: joe_f_90032 Date: 10/3/2017
Subject: Re: A bounty of new work- AWEC2017 Book of Abstracts

Group: AirborneWindEnergy Message: 23070 From: joe_f_90032 Date: 10/4/2017
Subject: Re: Alexander Muzhichkov

Group: AirborneWindEnergy Message: 23071 From: joe_f_90032 Date: 10/4/2017
Subject: Re: eWind Solutions news

Group: AirborneWindEnergy Message: 23072 From: dave santos Date: 10/5/2017
Subject: Re: eWind Solutions news

Group: AirborneWindEnergy Message: 23073 From: dave santos Date: 10/5/2017
Subject: KPS's new Glasgow HQ

Group: AirborneWindEnergy Message: 23074 From: dave santos Date: 10/5/2017
Subject: Collective spring-mass provision in metamaterial AWES design



Group: AirborneWindEnergy Message: 23025 From: joe_f_90032 Date: 9/18/2017
Subject: Re: Minesto news : 2017 summer new hires

Full name, please:


 Bernt Erik Westre
Group: AirborneWindEnergy Message: 23026 From: Joe Faust Date: 9/19/2017
Subject: ​Alphabet Remains Committed to Makani Wind, Says Startup
​Alphabet Remains Committed to Makani Wind, Says Startup

Makani will test its wind kite in Hawaii starting next year.
by Jason Deign 
September 18, 2017
==============================================
Group: AirborneWindEnergy Message: 23027 From: dave santos Date: 9/19/2017
Subject: Re: [AWES] ​Alphabet Remains Committed to Makani Wind, Says Startu
Even if GoogleX is "committed" to Makani, there is not great hope for testing in Hawaii. NASA's Helios platform dramatically failed from the Hawaiian Big island, and seeing the M600 either survive or crash-and-burn would be a spectacle in paradise.

They will have to have a near perfect safety-reliability record in a very public environmentally sensitive location. I personally know Fort Felker to be a fairly sharp general aerospace expert, but who is way in over his head in AWE, having blindly inherited the most complex over-engineered AWES architecture of all. The increasingly distant goal, from the established Google management pattern, will be to sell off Makani like the other fizzled "moon shots", claiming Pyrrhic victory.

At least we now have confirmation that Makani had not yet moved in Hawaii yet, just as our resident spotter network came up empty. We won't miss much with our Hawaii spotter base in Kona, a short drive from Waimea. We have not yet located the M600 California desert testing location from satellite images, as we located prior test sites.

Lets hope Makani does not cause a major wildfire, death or injury, and Hindenburg-moment for AWE. Whether Makani crashes or fizzles, its not true bad news for low-complexity AWE. The narrative of a flaming dinosaur is consistent with a soft-kite Phoenix rising from the ashes...


 

​Alphabet Remains Committed to Makani Wind, Says Startup

Makani will test its wind kite in Hawaii starting next year.
by Jason Deign 
September 18, 2017
==============================================
Group: AirborneWindEnergy Message: 23028 From: joe_f_90032 Date: 9/20/2017
Subject: Market report regarding some AWE matters. New or old author?


I've not yet identified the authors of the report. Critique of advertising text could be discussed. If anyone sees the report, then discussion of the report body text could be discussed. Is this from a fresh author source or is it new face for a known report maker?  If you have been interviewed by the source author, consider discussing such.  I received no call, no email, no visit, no contact; did you?


Report makers continue:


Global Airborne Wind Energy (AWE) Market 2017-2027: Active Developer/Supporter Profiles, Interviews And Plans

Group: AirborneWindEnergy Message: 23029 From: dave santos Date: 9/20/2017
Subject: Re: Market report regarding some AWE matters. New or old author?
Looks like a version of Harrop's AWE research.
--------------------------------------------
Group: AirborneWindEnergy Message: 23030 From: dave santos Date: 9/21/2017
Subject: Chanute's Lessons to AWE
Reading through his entire journal thread, mostly about "toys", Chanute reveals the same social pattern in early powered aviation that we see in AWE, just before world-changing technological success. One reads of dozens of passionate pioneers, that we now all know just how close were to our Aviation Age. Chanute admirably compiles foundational experimental and conceptual flight cases like no one before or since, excepting JoeF in AWE. These dreamers all served the purposes of study, many contributed some vital clue, and some were golden. One reads over the shoulders of the Wright Bros themselves, and comes away inspired, in AWE-
Group: AirborneWindEnergy Message: 23031 From: joe_f_90032 Date: 9/22/2017
Subject: Re: WindLift Update
Group: AirborneWindEnergy Message: 23032 From: joe_f_90032 Date: 9/24/2017
Subject: Generating interest

2. By Kites & Carriers


Lift and drop leaflets where wanted

to generate interest in a cause ....
Group: AirborneWindEnergy Message: 23033 From: dave santos Date: 9/24/2017
Subject: Re: Generating interest
Nice that we continue adding to our technical kite knowledge by vintage sources. We have learned to see kite messengers as secondary WECS harvesting (with the pilot kite itself as primary WECS). A messenger can pump a groundgen in principle, but no one we know has experimented the idea. The messengers in this WWI system are rather larger than the toys we have reviewed. 10,000ft high is pretty amazing to operate a kite messenger.

Leaflets is just one of endless things a messenger can convey. Hauling up skydivers is a cool app. Note the datum that a leaflet will float on wind ~10x release height v Bondestam's observation that runaway kites tend to glide in circles ~4x. The shorter hobby kite distance seems to be a complex scaling effect of surface wind gradient at lower altitude, rather than a large sink rate differential.



 

2. By Kites & Carriers


Lift and drop leaflets where wanted

to generate interest in a cause ....
Group: AirborneWindEnergy Message: 23034 From: joe_f_90032 Date: 9/24/2017
Subject: Re: Generating interest

Related:  Here

An encyclopedia note tells how the balloon won most of the propaganda delivery task; the kite method's tether was thought to be "a danger to aeroplanes."  Messrs. Gamage manufactured the balloons and releases.

Circa WWI.


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

Messrs. Gamage is mentioned in book:

THE THEORY AND PRACTICE
OF
MODEL AEROPLANING

BY
V.E. JOHNSON, M.A.

AUTHOR OF
'THE BEST SHAPE FOR AN AIRSHIP,' 'SOARING FLIGHT,'
'HOW TO ADVANCE THE SCIENCE OF AERONAUTICS,'
'HOW TO BUILD A MODEL AEROPLANE,' ETC.

"Model Aeroplaning is an Art in itself"


CLIP: "I have to thank Messrs. A.W. Gamage (Holborn) ... "
Group: AirborneWindEnergy Message: 23035 From: joe_f_90032 Date: 9/24/2017
Subject: Re: Generating interest
Group: AirborneWindEnergy Message: 23036 From: dave santos Date: 9/25/2017
Subject: The necessity and peril of small-scale AWES experiments
Our diligent study of early powered-aviation literature for comparisons to current AWE progress reveals a lost world of pioneering model aviation by dozens of experimenters over many years. Leading figures in powered-aviation, like the Wrights, Langley, Chanute, etc., all depended on lessons from model aviation. Without model aviation, none could have succeeded. Aerospace at the frontiers still relies on small-scale experiments. In AWE, small scale models are the fastest and cheapest to test, and scaling up prematurely for a "real" AWES is a trap. One must test small fast and cheap; or fail.

The danger in small-scale AWE R&D is to ignore applicable scaling laws. Many AWES concepts work at small scale but will not scale. The subtle scaling law we have discovered is that most-probable wind velocity does not scale up in proportion to the compounded flying mass of a scaled-up AWES. They must sit on the ground until a hurricane comes along. The developer needs an analytic leap, such as betting that greatest power-to-weight predicts greatest scaling potential. Logically, the WECS basis with the greatest power-to-weight is pure polymer at maximum working load. That still leaves many open optimization and down-select issues, but provides guidance to small-scale design.

The modern AWE developer should be prepared to change course and scale back as often as needed, rather than get stuck over-scaled with a dead-end down-select.
Group: AirborneWindEnergy Message: 23037 From: dave santos Date: 9/25/2017
Subject: Modern Interpretation of Lift and Drag Forces
Ever since Bernoulli published his famous Principle nearly 300 yrs ago, it has been misapplied to assert that it is the "correct" explanation of Lift. As Wikipedia notes, one can blow over or below a strip of paper, and in both cases the paper rises.*

A more modern explanation of wing Lift is the pressure differential between the top and bottom pressure fields is proportional to Lift. The same applies to Drag as proportional to the pressure differential between front and rear of a body. 

========
Group: AirborneWindEnergy Message: 23038 From: Peter A. Sharp Date: 9/25/2017
Subject: Modern Interpretation of Lift and Drag Forces
What is most important to understand about wing lift is that it requires an
angle of attack to the apparent wind. Wing camber serves to delay stall, and
thereby allows a higher angle of attack and a higher lift. Thin, flat wings
can produce lift, but they are limited to a low angle of attack. A vortex
bubble of swirling air forms behind and above the leading edge and functions
like wing camber.
PeterS
Group: AirborneWindEnergy Message: 23039 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces
Hi Peter,

The question is whether a "thick" airfoil with a flat bottom and cambered top develops Bernoulli lift at zero angle-of-attack (?)

If so, then AoA is not a definitive criteria. I must admit not to be sure,

daveS



 

What is most important to understand about wing lift is that it requires an
angle of attack to the apparent wind. Wing camber serves to delay stall, and
thereby allows a higher angle of attack and a higher lift. Thin, flat wings
can produce lift, but they are limited to a low angle of attack. A vortex
bubble of swirling air forms behind and above the leading edge and functions
like wing camber.
PeterS
Group: AirborneWindEnergy Message: 23040 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces
Wikipedia states: "cambered airfoils can generate lift at zero angle of attack," and "Asymmetric airfoils can generate lift at zero angle of attack"









 

Hi Peter,

The question is whether a "thick" airfoil with a flat bottom and cambered top develops Bernoulli lift at zero angle-of-attack (?)

If so, then AoA is not a definitive criteria. I must admit not to be sure,

daveS

On ‎Monday‎, ‎September‎ ‎25‎, ‎2017‎ ‎08‎:‎26‎:‎42‎ ‎PM‎ ‎CDT, 'Peter A. Sharp' sharpencil@sbcglobal.net [AirborneWindEnergy] <AirborneWindEnergy@yahoogroups.com


 

What is most important to understand about wing lift is that it requires an
angle of attack to the apparent wind. Wing camber serves to delay stall, and
thereby allows a higher angle of attack and a higher lift. Thin, flat wings
can produce lift, but they are limited to a low angle of attack. A vortex
bubble of swirling air forms behind and above the leading edge and functions
like wing camber.
PeterS
Group: AirborneWindEnergy Message: 23041 From: Peter A. Sharp Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces
Hi Dave,
That's a good question. The answer is very little and not nearly enough lift
to fly. That is what I have read. The calculations show the same thing
because the air going over the top of the wing just doesn't move much
farther, and therefore doesn't move much faster, and the Bernoulli Effect is
weak. But when the wing has an angle of attack, the air goes much faster
over the top than over the bottom of the wing and reaches the trailing edge
way ahead of the air moving under the wing which is slowed down
considerably. The bottom of the wing produces about 1/3 of the total lift
and the top of the wing produces about 2/3 of the total lift. Apparently,
the angle of attack amplifies the lowering of pressure over the top of the
wing and amplifies the slowing of air under the wing.
A common misconception is that the air flows traveling over and under the
wing meet at the trailing edge. They don't. With an angle of attack, the air
passing over the wind reaches the trailing edge way before the air passing
under the wing. I've seen videos of that.
As a result, when using the wing as the frame of reference, as seen from the
end of the wing, there is a circulation of air around the wing. The air on
top moves aft and the air on the bottom moves forward. That is the
"circulation" that aerodynamicists talk about when describing wing lift.
A Flettner rotor uses its own spin to increase that circulation, and thereby
increases lift to way beyond what a wing can produce, even with slats and
flaps to maximize the angle of attack.
PeterS
Group: AirborneWindEnergy Message: 23042 From: Peter A. Sharp Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces
Hi Dave,
Yes they can produce lift, but very little, as I explained in my last Email.

Most amateurs make a mistake when they look at a profile of a highly
cambered wing with a rounded leading edge and a flat bottom. They assume
that if the flat bottom is parallel to the apparent wind, then there is no
angle of attack. But that is incorrect. This is what many amateurs do not
understand: It is the angle of the chord to the apparent wind that
determines the angle of attack. The chord line is measured from the point
farthest forward to the point farthest aft. If the chord line is drawn for
that wing, it will be seen to be at a small angle of attack, not a zero
angle of attack. The greater the radius of the leading edge, in that case,
the greater the angle of attack.
Many science textbooks contain misinformation about blade lift, so many
amateurs have been misled. Unfortunately, Wikipedia is controlled by
anonymous amateurs, not identified professionals, so some misconceptions
tend to persist. Even worse, on some subjects, such as cycloturbine VAWT,
even many professionals have misconceptions because the subject is so
complex. And the amateurs or students just repeat those misconceptions
without taking the time to examine them in detail because to do so would be
prohibitively time-consuming and difficult. So some misconceptions persist.

PeterS
Group: AirborneWindEnergy Message: 23043 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces
We are left with the core fact that Lift of an airfoil is definable as the differential pressure between the two sides, not just low-pressure above nor just high-pressure below, and that Drag is similarly definable as pressure differential.

I am recalling data that some asymmetrical foils still develop some lift at slightly negative AoA. Zero AoA is in fact a useful high-velocity high-L/D cruising flight mode, depending on engineering intent. High AoA is reserved for slow flight, typically at take-off and landing.

The idea that "The bottom of the wing produces about 1/3 of the total lift and the top of the wing produces about 2/3 of the total lift." violates the assumption of force equilibrium of the two opposed pressure fields in steady flight.

Circulation is a second-order effect. The Flettner rotor is lift-limited by high flow-separation and high bluff-body drag. That's why no one can make a Flettner glider anywhere near the ~100L/D of a near-zero AoA wing on the hottest gliders. Note the characteristic flow separation in this Wikipedia image-







 

Hi Dave,
Yes they can produce lift, but very little, as I explained in my last Email.

Most amateurs make a mistake when they look at a profile of a highly
cambered wing with a rounded leading edge and a flat bottom. They assume
that if the flat bottom is parallel to the apparent wind, then there is no
angle of attack. But that is incorrect. This is what many amateurs do not
understand: It is the angle of the chord to the apparent wind that
determines the angle of attack. The chord line is measured from the point
farthest forward to the point farthest aft. If the chord line is drawn for
that wing, it will be seen to be at a small angle of attack, not a zero
angle of attack. The greater the radius of the leading edge, in that case,
the greater the angle of attack.
Many science textbooks contain misinformation about blade lift, so many
amateurs have been misled. Unfortunately, Wikipedia is controlled by
anonymous amateurs, not identified professionals, so some misconceptions
tend to persist. Even worse, on some subjects, such as cycloturbine VAWT,
even many professionals have misconceptions because the subject is so
complex. And the amateurs or students just repeat those misconceptions
without taking the time to examine them in detail because to do so would be
prohibitively time-consuming and difficult. So some misconceptions persist.

PeterS
Group: AirborneWindEnergy Message: 23044 From: dave santos Date: 9/26/2017
Subject: Second Test Session of Looping-Foil on Drive-Loop
Retuned, the latest looping-foil rig flew again yesterday, at the Dripping Springs Texas Park, with mixed success. The 9m2 pilot lifter was found not quite enough, struggling too much to counter the slight negative lift component of the looping foil, so a 22m2 pilot was tried, and worked much better, keeping a high overall flying angle. Shorting the looping kite lines helped the swivel bar unwind twist better, but they need more shortening yet. An adverse geometric effect seems to inhibit the looping kite when starting up, caused by mass-sag of the spreader bar. The ground capstan needs an elastic centering mechanism to keep the loop optimally registered, but stop-knots of the high wear loop sections are a crude fix. These are typical details to work out in ongoing testing.

This looping rig has now completed a few hundred nominal power loops, but the high Texas heat surface turbulence causes many upsets, including the pilots themselves. The rig did consistently self-relaunch, but bulk twisting of the multi-lines almost happened in the worst turbulence. It seems like the challenges will be overcome, but its slow going. I may revert to smaller scale testing to speed up progress, and because the gusty surge forces require a bit too much wrangling.

Watching closely what kites do over years enhances observability.  An maturing view in these looping kite sessions is that major dynamical metastable states, like the grounded state of a self-relaunching kite, have discrete usefully definable sub-states. Before a grounded kite can pop back up, it typically has to traverse a sub state-space, like rolling from its back to its belly or side, rolling from side-to-side, or rolling under the kite window to a sweet-spot, then finding its flight-ready orientation. This typically takes seconds in higher winds, and minutes in lower winds. More complex rigs have proportionally more complex state-spaces. Gradually art gives way to engineering science.
Group: AirborneWindEnergy Message: 23045 From: Peter A. Sharp Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Hi DaveS,

 

"We are left with the core fact that Lift of an airfoil is definable as the differential pressure between the two sides, not just low-pressure above nor just high-pressure below, and that Drag is similarly definable as pressure differential."

What? How could there be a pressure differential pressure without both the upper and lower pressures? Your statement makes no sense.

 

I am recalling data that some asymmetrical foils still develop some lift at slightly negative AoA. Zero AoA is in fact a useful high-velocity high-L/D cruising flight mode, depending on engineering intent. High AoA is reserved for slow flight, typically at take-off and landing.

Really? A high angle of attack is reserved for slow flight? So acrobatic planes and fighter planes don’t use a high angle of attack to maneuver? Nonsense. Crashes occur when a diving plane (high speed flight) pulls out of the dive too quickly and causes the wings to stall. Stall occurs at a relatively high angle of attack.

 

The idea that "The bottom of the wing produces about 1/3 of the total lift and the top of the wing produces about 2/3 of the total lift." violates the assumption of force equilibrium of the two opposed pressure fields in steady flight.

No it doesn’t. Consider a flat wing that is stalled so there is no drop in air pressure above the wing. It still develops lift due to the pressure below the wing. That lift will be roughly 1/3 of what it would be if the wing weren’t stalled.

 

Circulation is a second-order effect. The Flettner rotor is lift-limited by high flow-separation and high bluff-body drag. That's why no one can make a Flettner glider anywhere near the ~100L/D of a near-zero AoA wing on the hottest gliders. Note the characteristic flow separation in this Wikipedia image-

Flettner rotors are not “lift-limited”. Studies indicate that the lift will continue to increase as the spin ratio increases, with no known limit. It is the high drag that makes Flettner rotors poor wings for airplanes. So the L/D ratio is typically roughly about 4 to 6, which is not enough for most airplanes, and certainly not enough for most gliders. There are some slow-flying model airplanes that use Flettner rotors for wings.

 

https://en.wikipedia.org/wiki/Magnus_effect

This picture is for a ball in flight, not for a Flettner rotor. The ball has a relatively low spin ratio of less than 1, which is why there is so much separation behind the ball. Flettner rotors typically operate best at a spin ratio around 4. At that spin ratio, the separation occurs near the bottom of the cylinder, not near the top of the cylinder, as shown for the cross-section of the ball.  

Interestingly, the drag on a non-spinning ball can be reduced if it has just a little spin ratio, and just the right spin ratio. There is a name for that effect but I can’t remember it at the moment.
Group: AirborneWindEnergy Message: 23046 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces
A close reading shows we agree that its the summed pressure field on BOTH sides that count, not just one or the other, as vainly argued in past centuries, ever since Bernoulli was first misunderstood.

A stalled wing in fact develops a large relative low pressure behind the top surface, much as a drogue does. Again, in equilibrium flight, upper and lower pressure force fields are presumed to balance, under classical Newtonian physics.

Aerobatics with stalled wings are done at relatively lower speeds, or the wings break off, or the pilot goes unconscious. Take-off and landing at high AoA is just the more common engineering case.

There is a severe practical real-world thermal limit to the lift a Flettner rotor can develop by high RPM and high translation velocity, rather than a mysterious infinite lift potential. Such rotors sooner develop full separation of the boundary layer, since skin friction is limited much like tire traction is limited. Yes, the drag is limiting too, for practical purposes. You could say its still a case of a zero AoA wing that develops lift. In past discussion we dubbed this "virtual AoA".

Thanks for the interesting discussion.


 

Hi DaveS,

 

"We are left with the core fact that Lift of an airfoil is definable as the differential pressure between the two sides, not just low-pressure above nor just high-pressure below, and that Drag is similarly definable as pressure differential."

What? How could there be a pressure differential pressure without both the upper and lower pressures? Your statement makes no sense.

 

I am recalling data that some asymmetrical foils still develop some lift at slightly negative AoA. Zero AoA is in fact a useful high-velocity high-L/D cruising flight mode, depending on engineering intent. High AoA is reserved for slow flight, typically at take-off and landing.

Really? A high angle of attack is reserved for slow flight? So acrobatic planes and fighter planes don’t use a high angle of attack to maneuver? Nonsense. Crashes occur when a diving plane (high speed flight) pulls out of the dive too quickly and causes the wings to stall. Stall occurs at a relatively high angle of attack.

 

The idea that "The bottom of the wing produces about 1/3 of the total lift and the top of the wing produces about 2/3 of the total lift." violates the assumption of force equilibrium of the two opposed pressure fields in steady flight.

No it doesn’t. Consider a flat wing that is stalled so there is no drop in air pressure above the wing. It still develops lift due to the pressure below the wing. That lift will be roughly 1/3 of what it would be if the wing weren’t stalled.

 

Circulation is a second-order effect. The Flettner rotor is lift-limited by high flow-separation and high bluff-body drag. That's why no one can make a Flettner glider anywhere near the ~100L/D of a near-zero AoA wing on the hottest gliders. Note the characteristic flow separation in this Wikipedia image-

Flettner rotors are not “lift-limited”. Studies indicate that the lift will continue to increase as the spin ratio increases, with no known limit. It is the high drag that makes Flettner rotors poor wings for airplanes. So the L/D ratio is typically roughly about 4 to 6, which is not enough for most airplanes, and certainly not enough for most gliders. There are some slow-flying model airplanes that use Flettner rotors for wings.

 

https://en.wikipedia.org/wiki/Magnus_effect

This picture is for a ball in flight, not for a Flettner rotor. The ball has a relatively low spin ratio of less than 1, which is why there is so much separation behind the ball. Flettner rotors typically operate best at a spin ratio around 4. At that spin ratio, the separation occurs near the bottom of the cylinder, not near the top of the cylinder, as shown for the cross-section of the ball.  

Interestingly, the drag on a non-spinning ball can be reduced if it has just a little spin ratio, and just the right spin ratio. There is a name for that effect but I can’t remember it at the moment.
Group: AirborneWindEnergy Message: 23047 From: dave santos Date: 9/26/2017
Subject: AWEC 2017 buildup
UFreiburg PR; Moritz is rather optimistic utility scale AWE is only 3-7yrs away...



Text translation ("dragon" = kite)

Generate electricity in flight

Bye Windmills? Researchers are showing the latest developments in energy generation using high-speed wind turbines

Freiburg, 20.09.2017
 
Source: Makani / X
Dear Sir or Madam,
Dear Colleagues,
Anyone who has ever let a dragon climb in a strong wind knows what a dragon pulls on the string. The strength of the high-speed breeze, which is continually blowing at a height of 200 to 1,000 meters, can be used with steering kites or drones for power generation. Researchers and start-up companies at one

Press conference on Wednesday, October 4, 2017, from 1 pm to 2 pm
on the square of the Old Synagogue, 79098 Freiburg
Prototypes and current developments of high-altitude wind energy. The prototypes are open to the public from 2 to 4 pm. The press conference is part of the 7th international high-wind conference AWEC 2017, which will take place on 05 and 6 October at the University of Freiburg with more than 170 researchers from all over the world.
"With dragons or drones skimming the wind power on a rope high up in the air, we reduce a wind wheel to the wing tip," explains Prof. Dr. Moritz Diehl, organizer of the conference and professor of system theory, Microsystem technology at the Faculty of Technology, University of Freiburg, Germany The windmill and the rotor blades are superfluous, but wind turbines are still standing on the ground at high altitudes "The progress made in recent years is impressive," says Diehl. "I am convinced of the enormous potential of this technology. We assume that the first products with more than 600 kilowatts of power will be available in three to seven years. This corresponds to a medium-sized wind turbine, which covers the electricity requirement of 1,500 households. "
Group: AirborneWindEnergy Message: 23048 From: dave santos Date: 9/26/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces
Wikipedia's long article on lift covers a gamut of interpretations by the usual pack of editors, but contains this most concise and simplest statement of explanation-

"Lift is a result of pressure differences"










 

A close reading shows we agree that its the summed pressure field on BOTH sides that count, not just one or the other, as vainly argued in past centuries, ever since Bernoulli was first misunderstood.

A stalled wing in fact develops a large relative low pressure behind the top surface, much as a drogue does. Again, in equilibrium flight, upper and lower pressure force fields are presumed to balance, under classical Newtonian physics.

Aerobatics with stalled wings are done at relatively lower speeds, or the wings break off, or the pilot goes unconscious. Take-off and landing at high AoA is just the more common engineering case.

There is a severe practical real-world thermal limit to the lift a Flettner rotor can develop by high RPM and high translation velocity, rather than a mysterious infinite lift potential. Such rotors sooner develop full separation of the boundary layer, since skin friction is limited much like tire traction is limited. Yes, the drag is limiting too, for practical purposes. You could say its still a case of a zero AoA wing that develops lift. In past discussion we dubbed this "virtual AoA".

Thanks for the interesting discussion.
On ‎Tuesday‎, ‎September‎ ‎26‎, ‎2017‎ ‎04‎:‎54‎:‎31‎ ‎PM‎ ‎CDT, 'Peter A. Sharp' sharpencil@sbcglobal.net [AirborneWindEnergy] <AirborneWindEnergy@yahoogroups.com


 

Hi DaveS,

 

"We are left with the core fact that Lift of an airfoil is definable as the differential pressure between the two sides, not just low-pressure above nor just high-pressure below, and that Drag is similarly definable as pressure differential."

What? How could there be a pressure differential pressure without both the upper and lower pressures? Your statement makes no sense.

 

I am recalling data that some asymmetrical foils still develop some lift at slightly negative AoA. Zero AoA is in fact a useful high-velocity high-L/D cruising flight mode, depending on engineering intent. High AoA is reserved for slow flight, typically at take-off and landing.

Really? A high angle of attack is reserved for slow flight? So acrobatic planes and fighter planes don’t use a high angle of attack to maneuver? Nonsense. Crashes occur when a diving plane (high speed flight) pulls out of the dive too quickly and causes the wings to stall. Stall occurs at a relatively high angle of attack.

 

The idea that "The bottom of the wing produces about 1/3 of the total lift and the top of the wing produces about 2/3 of the total lift." violates the assumption of force equilibrium of the two opposed pressure fields in steady flight.

No it doesn’t. Consider a flat wing that is stalled so there is no drop in air pressure above the wing. It still develops lift due to the pressure below the wing. That lift will be roughly 1/3 of what it would be if the wing weren’t stalled.

 

Circulation is a second-order effect. The Flettner rotor is lift-limited by high flow-separation and high bluff-body drag. That's why no one can make a Flettner glider anywhere near the ~100L/D of a near-zero AoA wing on the hottest gliders. Note the characteristic flow separation in this Wikipedia image-

Flettner rotors are not “lift-limited”. Studies indicate that the lift will continue to increase as the spin ratio increases, with no known limit. It is the high drag that makes Flettner rotors poor wings for airplanes. So the L/D ratio is typically roughly about 4 to 6, which is not enough for most airplanes, and certainly not enough for most gliders. There are some slow-flying model airplanes that use Flettner rotors for wings.

 

https://en.wikipedia.org/wiki/Magnus_effect

This picture is for a ball in flight, not for a Flettner rotor. The ball has a relatively low spin ratio of less than 1, which is why there is so much separation behind the ball. Flettner rotors typically operate best at a spin ratio around 4. At that spin ratio, the separation occurs near the bottom of the cylinder, not near the top of the cylinder, as shown for the cross-section of the ball.  

Interestingly, the drag on a non-spinning ball can be reduced if it has just a little spin ratio, and just the right spin ratio. There is a name for that effect but I can’t remember it at the moment.
Group: AirborneWindEnergy Message: 23049 From: dave santos Date: 9/27/2017
Subject: Octave Chanute, "Father of Aviation"
Octave Chanute only began to focus on aviation in retirement from a brilliant civil engineering career, but he was so diligent and productive in his scholarship and mentoring that he moved the world upward. Without Chanute, the Wright Brothers would have been lost. Not only did Chanute provide comprehensive information, he gave "consistent encouragement" to pioneers (Wikipedia). So influential was Chanute that France and America led in aviation in large part because he was French-American. His fatherly role was underscored as he gently chided the Wright's for over-claiming patent rights and suing other pioneers, angering the Brothers, but on his death, they mourned him.

Similar dynamics exist in AWE, if not the same details. We rely on figures like Joe Faust and Wubbo Ockels in the Chanute role to carry folks forward. Whoever ends up in the Wright Brother's circle in AWE will likely depend in vital ways on Chanute's generous legacy.



Worth reading more than once, and still a model of lucid technical sharing-
Group: AirborneWindEnergy Message: 23050 From: Peter A. Sharp Date: 9/27/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces

Hi DaveS,

 

“A stalled wing in fact develops a large relative low pressure behind the top surface,…”

No it doesn’t. The air becomes highly turbulent and detached from the wing’s surface, so the pressure become essentially ambient. The Bernoulli Effect is lost. Wing stall causes a very large loss of lift. That loss would not occur if “a large relative low pressure” remained above the wing.

It is important to recognize that the upward pressure on a stalled kite -- due to drag alone -- can still be quite high. Many kites with a low aspect ratio develop more upward pressure from drag than they could generate from lift. Similarly, many VAWT use drag-type blades to create high torque while producing only a small amount of torque due to lift. The Savonius rotor is an example. So the high upward pressure on a stalled kite may create the illusion that the kite must be creating high lift (lower pressure above the kite). That is because drag is proportional to the square of the wind speed. The upward force due to drag along can become quite high.

 

Aerobatics with stalled wings are done at relatively lower speeds, or the wings break off, or the pilot goes unconscious.

You are claiming that an aerobatic plane in a dive operates at a relatively low speed. In that case, “relatively” includes speeds which are multiples of takeoff and landing speeds. So your assertion has no meaning because it could mean anything.

 

There is a severe practical real-world thermal limit to the lift a Flettner rotor can develop by high RPM and high translation velocity, rather than a mysterious infinite lift potential.

By “a mysterious infinite lift potential” (sarcasm?) you seem to be attempting to paraphrase what I said about how experiments with Flettner rotors have not found a limit to lift. If so, you are paraphrasing inaccurately. An unknown limit is not at all the same as an infinite lift potential. They simply did not find a way to determine how high the lift could go. As I recall, they reached a lift coefficient of about 19. No one has suggested that the lift of a Flettner rotor could be infinite.

You are asserting that the lift of a Flettner rotor is limited because it will burn up if the air speed is high enough. That is true, as it is true for wings in general, or any object that is not adequately heat shielded. But given the obviousness of your point, its relevance in not clear. Perhaps you are arguing that a Flettner rotor cannot have an infinite lift coefficient. But no one suggested it could.

In any case, you seem to have missed the point. The experimental finding I mentioned referred to the spin ratio being increased, not to an ever increasing air speed. The spin ratio is the surface speed of the cylinder divided by the air speed. For a given air speed, they found that increasing the spin ratio increases the lift. The results did not indicate what the limit on lift might be. Additional experiments might. In any case, the extreme lift of a Flettner rotor does not seem to have a practical application for flight because so much power is required to spin the rotor at high spin ratios. That same power could be much better used in other ways. A NASA scientist has claimed that the power required to spin the original Flettner rotors on ships would have resulted in a higher average ship speed if it has been applied directly to propulsion rather than to the Flettner rotors. But as I recall, he did not present his calculations.

PeterS

 

 

 
Group: AirborneWindEnergy Message: 23051 From: dave santos Date: 9/28/2017
Subject: Re: Modern Interpretation of Lift and Drag Forces
A further comment seeking to advance how Lift is interpreted-

In off-Forum discussion, PeterS asked about an airplanes that can maintain altitude with zero AoA. In an ideal view, a low-mass aircraft can in principle do so. In the real world, one could argue that exotic cases like the X-15 come very close, by ultra-high velocity. The new view we are gradually developing is that real-world airspace always contains some net vertical motion, and that's what soaring depends on, so in the real sky a common airplane flown at zero AoA can in fact maintain average altitude, and even climb, by playing rising air. Not everybody wants to be so exacting, arguing that a simpler view of the real sky is enough for their purposes, but for AWES concepts like Gabor's IFO, the existence of vertical motion is a vital Lift source.

Regarding whether a stalled wing develops high-lift, many kites operate at stall angles and Wikipedia again helps define terms-

"The critical angle of attack is the angle of attack which produces maximum lift coefficient. This is also called the "stall angle of attack"."







 

Hi DaveS,

 

“A stalled wing in fact develops a large relative low pressure behind the top surface,…”

No it doesn’t. The air becomes highly turbulent and detached from the wing’s surface, so the pressure become essentially ambient. The Bernoulli Effect is lost. Wing stall causes a very large loss of lift. That loss would not occur if “a large relative low pressure” remained above the wing.

It is important to recognize that the upward pressure on a stalled kite -- due to drag alone -- can still be quite high. Many kites with a low aspect ratio develop more upward pressure from drag than they could generate from lift. Similarly, many VAWT use drag-type blades to create high torque while producing only a small amount of torque due to lift. The Savonius rotor is an example. So the high upward pressure on a stalled kite may create the illusion that the kite must be creating high lift (lower pressure above the kite). That is because drag is proportional to the square of the wind speed. The upward force due to drag along can become quite high.

 

Aerobatics with stalled wings are done at relatively lower speeds, or the wings break off, or the pilot goes unconscious.

You are claiming that an aerobatic plane in a dive operates at a relatively low speed. In that case, “relatively” includes speeds which are multiples of takeoff and landing speeds. So your assertion has no meaning because it could mean anything.

 

There is a severe practical real-world thermal limit to the lift a Flettner rotor can develop by high RPM and high translation velocity, rather than a mysterious infinite lift potential.

By “a mysterious infinite lift potential” (sarcasm?) you seem to be attempting to paraphrase what I said about how experiments with Flettner rotors have not found a limit to lift. If so, you are paraphrasing inaccurately. An unknown limit is not at all the same as an infinite lift potential. They simply did not find a way to determine how high the lift could go. As I recall, they reached a lift coefficient of about 19. No one has suggested that the lift of a Flettner rotor could be infinite.

You are asserting that the lift of a Flettner rotor is limited because it will burn up if the air speed is high enough. That is true, as it is true for wings in general, or any object that is not adequately heat shielded. But given the obviousness of your point, its relevance in not clear. Perhaps you are arguing that a Flettner rotor cannot have an infinite lift coefficient. But no one suggested it could.

In any case, you seem to have missed the point. The experimental finding I mentioned referred to the spin ratio being increased, not to an ever increasing air speed. The spin ratio is the surface speed of the cylinder divided by the air speed. For a given air speed, they found that increasing the spin ratio increases the lift. The results did not indicate what the limit on lift might be. Additional experiments might. In any case, the extreme lift of a Flettner rotor does not seem to have a practical application for flight because so much power is required to spin the rotor at high spin ratios. That same power could be much better used in other ways. A NASA scientist has claimed that the power required to spin the original Flettner rotors on ships would have resulted in a higher average ship speed if it has been applied directly to propulsion rather than to the Flettner rotors. But as I recall, he did not present his calculations.

PeterS

 

 

 
Group: AirborneWindEnergy Message: 23052 From: dave santos Date: 10/2/2017
Subject: 2017 AWE R&D on-track by Critical Path Analysis
In 2011 WoW and KiteLab collaborated on a simple critical-path analysis of claimed peak power values in testing across all teams, starting from 2007 data. The scatter plot seemed to show a "hockey stick" trend of increasing peak power milestones. Revisiting the trends every couple of years has upheld expectations. KiteNRG's standing ~100kW claimed peak has given way to Makani's ~600kW claim, as the top claims, more or less as predicted.

Peak output is a very crude but significant metrical view. It ignores many higher order parameters, like full cycle output and critical reliability, factors which can nevertheless be depended on to be improving in parallel. Its not the same as a TRL rating, but TRL is very scale dependent, and we have small-scale TRL9 AWES like KiteSat, while large scale capability naturally lags. There is also a perception that small experimenters are less active, based on fiful social media activity, even as the recorded number of active teams and ventures has only grown.

The overall progress projection made in 2011 is holding, that the period from around 2025-30 will see MW scale electrical generation demonstrations, and possibly utility-scale commercial kitefarm deployment, depending also on broad political and business factors. Despite so many uncertainties, the upper-wind resource is as real as ever, AWES domain art and knowledge continues to accumulate, and the arc of history of world-changing engineering advances is relentless. 
Group: AirborneWindEnergy Message: 23053 From: dave santos Date: 10/2/2017
Subject: A bounty of new work- AWEC2017 Book of Abstracts
This is conference week, and the AWEC 2017 Book of Abstracts offers a flood of new faces, updates, and confirmation that a great diversity of approaches is still in play, that the AWE field remains quite open. Compared to earlier days, when only a handful of players existed to study, it will now take quite an effort to fully review current activity. In general, many theoretic factors identified in past years are being specifically tested by multiple independent parties, ultimately resolving all engineering uncertainties, in due time.

Enjoy the feast- 
Group: AirborneWindEnergy Message: 23054 From: joe_f_90032 Date: 10/3/2017
Subject: Fusing Kite and Tether into one Unit

Lars Bäckström of Umea University
Tom Guilloux of ESTACA, Laval
Fusing Kite and Tether into one Unit

[Note: in forum, one strand of "kite" is ever a fusing of wings with tethers, even anchors of system being fused as special wing sorts. Lars Bäckström and Guilloux are exploring opportunities upon such basis.]



Group: AirborneWindEnergy Message: 23055 From: dave santos Date: 10/3/2017
Subject: Re: Fusing Kite and Tether into one Unit
This is a good example of unconventional thinking still welcomed in AWE; the sort of marginal idea that might not compete today, but keeps us thinking.

In effect this concept is a soft-bladed rotor in autogyro mode, with the hub kept on the ground. There are some basic challenges, like a limit to how high this sort of WECS can reach in proportion to how wide it can be and still DS its upwind phase. High inertial penetration mass and high L/D would be required. This could work in some future situation with superior materials and engineering. There is also a design continuum between this tether-wing and a standard wing-on-a-tether, with the dreamed-of faired-tether somewhere in-between.

Note that no one has yet made a faired-tether clearly superior to a plain tether. A fairing adds mass, cost, and tends to be fragile. The place for tether fairing to begin to pay off is near a hot sweeping kiteplane, where velocities are high. There scanter advantage to fairing slower-moving lower tether sections.



 

Lars Bäckström of Umea University
Tom Guilloux of ESTACA, Laval
Fusing Kite and Tether into one Unit

[Note: in forum, one strand of "kite" is ever a fusing of wings with tethers, even anchors of system being fused as special wing sorts. Lars Bäckström and Guilloux are exploring opportunities upon such basis.]



Group: AirborneWindEnergy Message: 23056 From: joe_f_90032 Date: 10/3/2017
Subject: Kitepower's "Model A" ground station

Kitepower's "Model A" ground station

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

Peak power: 180 kW

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

http://cordis.europa.eu/result/rcn/198196_en.html

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

Their kite system has a part: ground station. Hence the "kite" has parts, one of which is an anchor system holding generator.  What is the total mass of the ground station? What is the ground station's interface with terra firma? The ground station may be seen as a complex short tower in this case; the ground station is designed to be moved from one operational site to another when wanted.   

============================
Group: AirborneWindEnergy Message: 23057 From: joe_f_90032 Date: 10/3/2017
Subject: Re: Kitepower's "Model A" ground station
Group: AirborneWindEnergy Message: 23058 From: joe_f_90032 Date: 10/3/2017
Subject: Hiroshi Okubo

Hiroshi Okubo, Kanagawa IT
High-Sky Wind Energy Generation on Tethered System

Professor at Kanagawa Institute of Technology
Department of Mechanical Engineering
okubo@me.kanagawa-it.ac.jp
www.mech-kait.net

Proceedings of WWEC2016 TOKYO C36, University of Tokyo, Japan, 2 November 2016

http://wwec2016tokyo.com/

C-3-6 Air Borne Wind Energy Generation on Tethered System Hironori Fujii, Hiroshi Okubo, Yusuke Maruyama, Tairo Kusagaya, Takeo Watanabe   


Group: AirborneWindEnergy Message: 23059 From: joe_f_90032 Date: 10/3/2017
Subject: Re: Hiroshi Okubo
Group: AirborneWindEnergy Message: 23060 From: joe_f_90032 Date: 10/3/2017
Subject: Re: Hiroshi Okubo

References in the 2016 paper:

References



[1] Fujii,H.A., Okubo,H., Arakawa,K., Kusagaya,T., Stroeks,R.,Takahashi,Y., Endo, H., Watanabe,T., Maruyama,Y., Nakajima, T., Asou, T., and Seki,K., "Progress Report on Study of Air Borne Wind Energy," (in Japanese), Japan wind energy association, Vol.40, No.1(Total 116), 2016 February.


[2] Fujii,H.A., Maruyama,Y., Motegi,Y., and Kida,K., "A MODEL DEMONSTRATION OF KITE-TYPE WINDMILL," International Conference and Exhibition, Grand Renewable Energy 2014, July 27-August 1, 2014, Tokyo Big Sight, Japan



Group: AirborneWindEnergy Message: 23061 From: dave santos Date: 10/3/2017
Subject: Re: Kitepower's "Model A" ground station
TUDelft's AWES research ground station (groundgen and reel) is way overbuilt compared to future optimized designs, but at least the scientists need not be distracted by broken ground hardware to trial novel airborne factors. The mass looks like ~1000kg, which may be enough to hold place in moderate winds by sheer dead-weight. At Valkenburg, they can likely adopt standard aircraft tie-downs to secure against dragging. Long term, expect ground hardware to approach ~1kW per kg and 
Group: AirborneWindEnergy Message: 23062 From: joe_f_90032 Date: 10/3/2017
Subject: Re: Japanese ~VAWT under Kite Train AWES video
Ref: "Experimental Study of Tether-Sprocket Type Airborne Wind Power", The 2016 Asia-Pacific International Symposium on Aerospace Technology, SBM000366 (2016).
========================
Group: AirborneWindEnergy Message: 23063 From: joe_f_90032 Date: 10/3/2017
Subject: Re: [AWES] ​Alphabet Remains Comm itted to Makani Wind, Says Start

Oct. 2, 2017, Fort Felker is optimistic:


HERE he declares

========================
Group: AirborneWindEnergy Message: 23064 From: joe_f_90032 Date: 10/3/2017
Subject: Re: [AWES] ​Alphabet Remains Comm itted to Makani Wind, Says Star

Someone might notice in one of the photos:

there seems to be three towers involved in the system.
Group: AirborneWindEnergy Message: 23065 From: joe_f_90032 Date: 10/3/2017
Subject: Lista, Norway : Lista Airborne Wind Energy Center AS

Lista Airborne Wind Energy Center AS

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

Thread here is open for the unfolding history of the center at Lista, Norway.
Group: AirborneWindEnergy Message: 23066 From: joe_f_90032 Date: 10/3/2017
Subject: Unmanned Valley Valkenburg (UVV) in Netherlands

Unmanned Valley Valkenburg (UVV) in Netherlands

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

This topic thread is open to the unfolding history of the special site.

Group: AirborneWindEnergy Message: 23067 From: joe_f_90032 Date: 10/3/2017
Subject: Airborne Wind Europe

Airborne Wind Europe

=================
Group: AirborneWindEnergy Message: 23068 From: joe_f_90032 Date: 10/3/2017
Subject: Airborne Wind Earth

Airborne Wind Earth

===============
Group: AirborneWindEnergy Message: 23069 From: joe_f_90032 Date: 10/3/2017
Subject: Re: A bounty of new work- AWEC2017 Book of Abstracts

Author Index for the Book of Abstracts for AWEC 2017



Abdel-Khalik, Ayman S., 77
Affentranger, lorenz, 95
Ahbe, Eva, 86
Aliouat, Abdelhadi, 45
Arakawa, Kazuo, 136, 154
Araujo, Helmut, 33
Aregger, Damian, 61
Backstrom, Lars, 41
Barbi, Ivo, 33
Bastigkeit,lIona, lOS, 106
Bauer, Florian, 73
Baumann, Leo, 9S
Beatch, Jason, 81
Beaupoil, Christof, 133
Bechtle, Philip, 24
Bedon, Gabriele, 171
Bellusci, Giovanni, 164
Bezard, Florian, 61
Bormann, Alexander, 63, 123
Sarabia-Moreno, Ricardo, 26,32
Bourgault, Frederic, 81, 129
Breuer, Jeep, S1, 161
Bricteux, Laurent, 143
caboni, Marco, 171
Campagnolo, Filippo, 73
Candade, Ashwin, 123,150
canonica, Renate, 95
camel, Lode, 55, 157
catel, AunWe, 91
Cha, KyoungHo, 134
Cha, MinJae, 134
Cherubini, Antonello, 131
Chin, Eric, 139
Cobb, Mitchell, 153
Coleman, Joseph, 80
Costa, Dina, 61
Coudou, Thomas, 143
Crawford, Curran, 106
Dorenkamper, Martin, 106
Damas, Carlos Perel,104
Damron, luke, 81
De Lellis, Marcelo, 33
De Oliveira, Gael, 135, 146
De Schutter, Jochem, 43, 169
Deese, Joe, 153
Deodhar, Nihar, 153
Dewan, Ashish, 171
Dief, Tarek, 165
Diehl, Moritz,S, 29, 43, 74, 85, 119, 163,
164,169
Drenth, Sit, 173
Dumon, Jonathan, 34, 45, 91
Dunlap, Andrea, 113
Duport, Chloe, 30
Ebrahimi 5alari, Mahdi, 80
Eldeeb, Hisham, 77
Elmendorp, Reno, 71
Endo, Hiroki T., 136, 154
Erhard, Michael, 99
Ermanni, Paolo, 31, 95, 147
Exposito, Daniel,120
Fagiano, Lorenzo, 15
Fasel, Urban, 31, 95, 147
Faulwasser, Timm, 90
Fechner, Uwe, 135, 146, 165
Felker, Fort, 13
Ferreira, Carlos, 27
Feuchtwand, Julian, 39
Folkersma, Mikko, 144
Fontana, Marco, 131
Fontes, Fernando A.C.C,103
Friedl, Felix, 102
Fujii, Hironori A., 136, 154
Gohlich,Dietmar,127
Galliot, Cedric, 61
Garda-Villalba, Manolo, 32
Gebhardt, Christian, 63
Gehri,Ivan,95
Gehrmann, Thomas, 24
Genin, Raphael,45
Giovanni, licitra, 29
Girrbach, Fabian, 164
Gohl, Flavio, 61
GOlluklu, Burak, 104
Gros, Sebastien, 169, 170
Guilloux, Tom, 41
Gunn, Kester, 184
Gupta, Yashank, 34
HArklau, Thomas, 46
Haas, Thomas, 107
Hably, Ahmad, 34, 45,91
Hackl, Christoph M., 73, 77
Hallamasek, Kurt, 139
Harrop, Peter, 64
Hauke, Christoph, 63
Heilmann, Jannis, 61
Heyes, Simon, 69
Hoi, Jeroen D., 164
Horn, Greg, 85
Houle, Corey, 61
Hummel, Jan.127
Jochum, Christian, 30
Jones, Colin N., 90
Konig, Gabriel, 95
Kakavand, Mani, 115
Keidel, Dominic, 31, 95, 147
Kennel, Ralph, 73
Kheiri, Mojtaba, 81, 129
Koenemann, Jonas. 29, 74
Krishnan, Navaneetha, 143
Kruijff, Michiel,19
Kugelberg, Gustaf, 52
Kusagaya, Tairo, 136
Leloup, Richard, 149
Leroux, Jean-Baptiste, 30
Leuthold, Rachel,S, 27, 169
Licitra, Giovanni, 163
Listov, Petr, 90
Lopez, Ysoline, 45
Luchsinger, Rolf H. I 61
Maison, Antoine, 30
Mall, Elena, 169, 170
Maruyama, Yusuke, 136
Mattia, Cia, 95
Meinert, Tore, 157
Menanteau, Philippe, 45
Meyer, Johan, 107
Michalski, Andreas, 95
Miller, Paul,139
Molinari, Giulio, 31, 95, 147
Mu, Mike, 139
Neme, Alain, 30
N0ttveit, Harry, 157
Nguyen-Van, Eric, 15
Oehler, Johannes, 125
Ohler, Christian, 15
Okubo, Hiroshi,136, 154
Oostrum,lucas van, 161
Paiva, Luis Tiago, 103
Pastor-Rodriguez, Alejandro, 32
Patt, Michael, 73
Payan, Estelle, 45
Pereira, Ricardo, 146
Peschel, Johannes, 51
Petrick, Kristian, 109
Prabu Sai Manoj, Mandru, 27
Python, Benoit, 25
Quack, Manfred, 99
Quick, Megan, 183
Raffray, Tanguy, 149
Rager, Felix, 15
Ranneberg, Maximilian, 123, 145, 150
Rapp, Sebastian, 89
Read, Roderick, 37, 39
Rieck, Burkhard, 123
Rohde, Peter, 105
Roncin, Kostia, 30
Rudolph, Claudia, 105
Ruiterkamp, Richard, 19, 137
Sanchez~Arriaga, Gonzalo, 26, 32, 120, 154
Saberi Nasrabad, Vahid, 81, 129
Saidi, Aissa, 45
Salma, Volkan, 102
Samuel, Karine, 91
Sanjurjo-Rivo, Manuel, 32
Saraiva, Ramiro, 33
Saraswati, Novita, 111
Scarito, Michael, 139
Schols, Tobias, 119
Schepers, Gerard, 111
Schlagenhauf, Jonas, 119
Schmehl, Roland,S, 26, 27, 32, 51,73, 89, 102, 109, 125, 131, 141, 143,144,150,165,177
Schmidt, Eduardo, 140, 166
Schnel, Stephan, 15
Seki, Kazuichi, 136
Sieberling, Soren, 29,74,163
Sieg, Christoph, 24
Silva de Oliveira, Romulo,140
Skutnik, Stefan, 63,123
Smith, Roy 5., 86
Soler, Manuel, 120
Sommerfeld, Markus, 105, 106
Steenhuizen, Dirk, 71
Steiner, Julia, 128
Steinfeld, Gerald, 106
Stiesdal, Henrik, 21
Stirr, Kate, 113
Szalai, Balazs, 131
Takahashi, Vasutake,136,l54
Thedens, Paul,141
Toal, Daniel, 80
Todd, Devin, 81
Trofino, Alexandre, 33
Tucker, Nicholas, 183
Tulloch, Oliver, 39
Uchiyama, Kenji, 136
Uhrhane, Eric, 139
van Hemert, Bernard, 44
Vermillion, Chris,153
Versleijen, Anoushka, 161
Victor, Samson, 129
Vimalakanthan, Kisorthman, 171
Vir., Axelle, 128,143,144
Wolffe, David,10B
Wall, Henrik, 184
Watanabe, Takeo, 136
Wiesemliller, Fabian, 95
Wild, Oliver, 95
Wilhelm, Stefan, 109
Williams, Paul, 29, 137, 163
Winter, Matheus, 140
Wood, Tony A., 86
Yoshida, Shigeo, 136, 165
Vue, Hong, 39
Zanelli, Andrea, 85
Zillmann, Udo, 24, 109, 179


[ We join this for fusing with Airborne Wind Energy Industry Participants List]
Group: AirborneWindEnergy Message: 23070 From: joe_f_90032 Date: 10/4/2017
Subject: Re: Alexander Muzhichkov

New changes, results, sites:


New 2017 : 
                Alex



Group: AirborneWindEnergy Message: 23071 From: joe_f_90032 Date: 10/4/2017
Subject: Re: eWind Solutions news

Social Impact finalists named for Bend Venture Conference (BVC)


One of the four finalists:

" eWind Solutions, of Beaverton, a renewable airborne wind energy company utilizing a rigid wing kite to produce energy."
Group: AirborneWindEnergy Message: 23072 From: dave santos Date: 10/5/2017
Subject: Re: eWind Solutions news
eWind has been technically limited by its insular "not-invented-here" AWE engineering culture, including haughty avoidance of local open-source kite expertise in the US NW. They have instead seemed more focused on venture promotion and public (USDA) funding. Its near time for them to duly reveal their AWES deliverable, which may fall very short of practical value in the remote small-scale AWES app space, compared to the crowd of more open team efforts worldwide. Good Luck to them in not having wasted public funds, and successfully delivering what they have claimed.



 

Social Impact finalists named for Bend Venture Conference (BVC)


One of the four finalists:

" eWind Solutions, of Beaverton, a renewable airborne wind energy company utilizing a rigid wing kite to produce energy."
Group: AirborneWindEnergy Message: 23073 From: dave santos Date: 10/5/2017
Subject: KPS's new Glasgow HQ
Lets hope KPS's field activity meets or exceeds its urban presence. The major failing of many AWE ventures is to be more PR and VC oriented than be essential hands-on problem-solvers.
Group: AirborneWindEnergy Message: 23074 From: dave santos Date: 10/5/2017
Subject: Collective spring-mass provision in metamaterial AWES design
Many AWES pumping concepts depend on "passive" dynamic spring-mass oscillation. Even a standard power-kite doing eights stores a bit of energy in surge phases returned in recovery phases. UMWPE is in fact a fairly high Q-factor spring, and tuned spring-mass of tether, kite, and entrained air, including wake, can promote sustained spring-mass oscillation. A power kite is thus felt to want to fly itself, "in the groove" doing lazy-eights, except as disturbed by turbulence.

Extending the single pumping unit-kite to an airborne periodic array performing coherently pumping can be done many ways. The most obvious is for each unit-kite to comprise its own spring-mass, but passive coherent coupling of weakly coupled kites is not as robust as collective spring-mass provision. Instead, a kite array can be crosslinked by low-stretch lines and the spring-mass effect developed as a whole.

The desired elastic mass can even be kept at the surface, saving weight aloft. The groundgen system can include intial elastic-return of its motion limit-cycle in order to regulate the pumping of the airborne array. In the metamaterial approach, the surface can be a spring-mass network excited by airborne energy extraction. Such fundamentals of the AWES metamaterial paradigm are becoming well-understood.

Open-AWE_IP-Cloud