I would expect hundreds of crashes as a matter of course in such experimentation. Not sure what is so remarkable about that. And Dave, S. yes they should be running all this stuff by you. What are they thinking? Do I publicize every failure? Nope, busy fixing whatever want wrong. A few years of that and after a while nothing goes wrong. Not as easy as one would imagine but persistence pays off eventually.
Still wondering what exactly happened to Corwin, if anyone knows by now, and why, if they are in business, have they not answered their phone for 5 months now.

I agree that what Dave S. stated below is probably a major factor. I've slowly realized that green energy news is actually mostly lies (hopefully told) with a few tidbits of truth here and there.

Of course if Makani wanted to spend THEIR time on this list debunking all the hype and false statements of, well, let's say a Dave S., they would never get anything else done! Trying to shut down a firehose of nonsense that powerful is a full time job. If Makani wanted to compare accomplishments versus unsubstantiated hype with Dave S., its not hard to see who would come out ahead.

But I think there's another dynamic afoot as well.
I think it comes down to talking versus doing.
Some people do things, other people talk about doing things.
While nobody can yet say Makani has an ECONOMIC solution to power generation, they at least have something that works. It flies and generates more than a watt or two. The don't fly some little kite that wiggles a bit, lash together tarps and see if they can lift off the ground, or craft a little foam propeller, and claim thereby to have explored some space of AWE. They are (or were) at least doing SOMETHING.

And talking about what they are doing on an open forum of less than 200 people, most of whom have nothing to offer anyway but are merely interested, and a few of whom are openly antagonistic - well what can it get them besides a sound thrashing if they ever claim any success? Maybe they start spilling their IP - like "OH we should't have revealed that on the forum last year cuz this year we realized part of what we said would have been part of our next patent!"
On the other hand, we've had a LOT of brainstorming on the list. But most of the ideas probably:
1) wouldn't work at all
2) are incompletely thought out
3) do not take into account knowledge of wind energy
4) would not last if they were ever built
5) have nothing to do with AWE
6) date back to earlier centuries
So if a Makani were on this list, what would they get?
Ideas? from us?
Well I tried calling them a few more times.
Now the number is busy instead of just ringing.
Seems to be "off-the hook" (or is that a term from the 1800's?)
Now most of our phones are off the hook all the time - not attached to a wall or anything.
Soon all our wind turbines will be too.(?)
:)

Direction of moving mass from one kite system to another kite system to another kite system to another kite systems, etc. :

Morning Steve, 

To criticize makani is a little bit difficult: on one hand their project is one of more advanced and better prepared in AWE,so to critic Makani is to critic AWE; on the other hand it is not very probable that as is he can compete with classic turbines.

 

PierreB

(correction) To criticize makani is a little bit difficult: on one hand their project is one of more advanced and better prepared in AWE,so to criticize Makani is a little to criticize AWE; on the other hand it is not very probable that as is he can compete with classic turbines.

 

Concerning Makani's progression I do not see any errors but only a choice with all its logic (high L/D ratio,continuous power...) with inherent advantages and problems. 

 

Our forum is interesting because it allows to see what schemes cannot work as utility-scale system,maybe the reasons why AWE cannot work in the end. 

 

PierreB

This is a preliminary call-out for an AWE R&D encampment to take place this spring near Austin Texas. All are welcome.

We will return to Valley Way Farm, site of MOTHRA1's maiden launch to continue testing, evaluating, and upgrading our systems. Power kiting and AWES workshops will be featured continuously as well as presentations and demonstrations. Media production and business networking will be key activities.

The emphasis of the encampment is field testing, so come ready to fly..

We will get going mid April and run about a month in order to accommodate busy schedules. We would like to see a concentration of activity around a single week (to be announced).

Camping arrangements are flexible. Hotels are available near the hay farm. Guests are asked to cover basic encampment costs (food and carpooling) as a group (25 USD per diem estimated).

Contact Ed Sapir at edoishi@yahoo.com for more information.

DaveS,

 

Makani makes a good job as rigid flygen making.The same for Ampyx with rigid reel-in/reel-out making.The same for Altaeros with aerostat containing a turbine.The same for Sky Windpower,etc...All people working in these companies and others are experts in AWE.But it is perhaps not enough to make utility-scale AWE.

 

PierreB

http://en.wikipedia.org/wiki/Gamification 

Well stated.

Learn - make it - break it.
Learn - make it - break it.
Learn - make it -

Doug and all,

Doug wrote:"But most of the ideas probably:...
3) do not take into account knowledge of wind energy".

It would be interesting you indicate technical issues,excepted
reliability and efficiency you made.

When we will have all elements the choice for AWES scheme (for me
something like autogiro-mode and variants) will be easier.

I point often the fact that crosswind kite (not autogiro,but with
movable tether linking the single kite,like Makani or Ampyx) produces
cyclic irregular power,even during power phase,even for flygens like
Makani or mine.

It is a little like the rotor of a conventional wind turbine,making a
complete rotation per 2 seconds,made 1 kW the first second,2 kw the
second second,or something like.Questions to Doug:in such a case,what
would be the problems,what additional devices would be
required,regarding for example supercapacitors (high cost),or quite
different devices like wind turbine power converter system (WTPCS)?

PierreB

Are you saying your work is more comprehensive and significant research than Makani?

At least they are not trying to generate energy with a winch, and if their machine has a wobble it means there is something wrong, not that a wobble is its operating principle...

Yes I agree a debate with you is a no-win proposition - good characterization! ;)

By the way,
I was wondering,
if we were trying to get Makani
to participate in this list...
What if
Just what if...
we promised to be nice???

Hi Pierre:
Solving the AWE challenge requires focus on what really works well, not how many band-aids one can apply to what does not work well.
The wind is variable and wind turbines seldom produce a steady output.

If you have a windfarm, you get an average output from all the turbines so the fluctuations slow, but the wind goes from zero to full power and beyond. What you are talking about is adding more fluctuation. So the steps taken to smooth that output, if any, might be more desirable. My opinion is that trying for a steady-state output to the extent possible would be best, all else being equal.

What I mean by "not taking into account knowledge of wind energy" is that people who run wind turbines know that the wind is so brutal that everything has to be simple and clean and not shaky and fine-tuned to respond quickly to gusts, and able to hang in there when thew ind hits 80 mph and nobody is around, using the moste fficient airfoils known, high speed blades hardened for 20 years of service, etc. And still things go wrong.

So when we see something like a Magenn, we think they didn't consult real wind energy people. It's an inefficient design - wind people know that. And the same sort of thing for a lot of these schemes - real wind people know how fast stuff wears out, how everything that can go wrong does go wrong, how you gotta keep it simple and clean and smooth and steady, and then you are still looking at a huge challenge.

I have said it before, most of what we see in AWE is just previous bad ideas taken into the air. But hats off to everyone who is trying anything and getting any kind of results. Really we don't know for sure what will turn out to be a good idea or not, and we don't know where even a bad idea could lead to a good idea. So I guess we all gotta just keep trying. Obviously there is no shortage of free advice for anyone who wants it! :)

The title of this thread is exactly what I mean - it makes no sense for people in wind energy - the word "vs" - "versus": crosswind kite power IS not "versus" a conventional wind turbine. Crosswind kite power IS a conventional wind turbine, it's just that in the past 2000 years the cloth of the kites first got attached to a central pivot, then each kite got a frame behind it giving at an airfoil shape, and got longer for a better aspect ratio, then had resin added to the cloth to harden it up for 20 years of service. You gotta pay attention! The rest of the class is producing Megawatts and you are 2000 years behind - wait, 3000 years behind! - back at wondering if the wind can push something then what next? If the wind can pull a string... hmmm so the wind can push and the wind can pull - gosh what should we do? Let's make a push-me-pull-you!
:)
Doug Selsam

Doug and DaveS,

 

"Crosswind kite power" (M.Loyd's definition),concerned AWES:Makani (not autogyro-mode),FlygenKite,Ampyx,KiteGen Stem,Enerkite...,all kite systems making figures like loop or eight to sweep more and produce more energy.Conventional wind turbines and autogyro-mode make also crosswind power,but with regular power (if wind speed does not move).At the contrary "crosswind kite power" has cyclic irregularities.So for several reasons crosswind kite power is not quite the same as crosswind turbine power.Thanks to Doug for the explains.Indeed the point of view from regular wind energy is relevant to see what can be made in AWE.

 

PierreB 

 

 

"The kite's motion would be approximately transverse to the wind, in the same sense that a wind turbine's blade moves transverse to the wind."

Miles Loyd


Conclusions-

Loyd did not limit the "crosswind" AWES definition to Payne's original Turbine-on-a-Wing concept.

Back and forth, up and down, looping, and figure 8s are all allowable Crosswind Kite Power flight patterns, as long as the overall motion is "approximately transverse".

Most wind engineers understand this just as Loyd does. Below are two correct usages of "crosswind power". Note that the kite link is to a figure-8 AWES-

http://www.crosswindpower.ca/

http://www.crosswindpower.com/%c2%a0%c2%a0

By Loyd's formal definition, this is a valid Cross-Wind Kite Power concept-


Re: [AWES] mothra kite bunch
Fri Nov 9, 2012 8:03 am  

http://www.energykitesystems.net/OrthoKiteBunch/index.html

I know - I didn't mean you with a winch. You are using quantum phonons from a Bose-Einstein condensate array of kites. Well what the heck, give it a try!

Pause on "cyclic irregularities" of the large tri-blade HAWT crosswinding: 

Concerning winch,or reel-in/reel-out,one big problem is loss of time and energy during recovering.With Ampyx the problem is lesser because power is realized at high speed of wing,so the relative wing's area is low,and losses probably lesser.Another problem of winch is the difficult management.Another problem is the wear of tether...

PierreB

Mothra as kite bunch?

 

PierreB

Hey Dave:
After 10 years of listening to wind energy crackpots bragging about their insane notions, it's easy to spot. At least most of them are pointing to an actual machine they have built, They brag incessantly, while complaining how they need to find the right generator to connect it to, for final proof, and ultimate glory. They attack all who would question them, promising to leave a trail of surprised and bewildered former-detractors and formerly-skeptical experts in their wake. Looking forward to seeing you and Einstein "shaking up" the field of wind energy. :)

Pierre:
Thanks for reviewing those problems with reeling again.
How 'bout if I say the same thing again for the hundredth time too?
"Imagine a GE wind turbine on rails, with no generator and its rotor spinning unloaded, trying to make power by moving upwind and downwind on the rails pulling a winch, then adjusting the pitch and rellin in the turbine. Would not this seem like a very silly way to try to take power from a wind turbine? Just sayin'...

Man are you still bogged down trying to figure out if the blades should travel perpendicular to the wind? Still trying to grasp it? You need some guy named Lloyd to explain it to you? again? Do you need Christina Archer with a PhD to explain that there is more wind the higher you go? OK Great we have the basics: There's more wind up there and the best way to harvest it is airfoils moving across it. That was day 1 of AWE. This is day 1000. What have you got now?

I don't think our words are accomplishing anything more if they ever did. Imagine the amount of time and effort going into this "you-said, he-said" crap. What does it all mean? Nothing. Great you spotted Magenn as a scam. Congratulations. Give yourself a medal. Your really want to take your otherwise-valuable time to imply that somehow I did not see Magenn as a scam?

I think I was denouncing Magenn as a scam on real wind lists before we even HAD a group. Anyone with the slightest bit of knowledge agreed. It amounted to absolutely nothing. Anyone who ever thought it amounted to anything knew nothing. There are no words strong enough to describe its level of ineffectiveness compared to its hype. What you don't understand is this is not restricted to Magenn, just that Magenn is an extreme enough example for you to grasp how dumb it is.

But we wind energy people never saw Magenn as anything unusual, just one more of a thousand similar machines, all promoted by impossibly stubborn and misinformed and highly argumentative people who thought that arguing about their designs on the internet was a substitute for hours in operation and power output data.

It was a comedy then and it is a comedy now.
:)

Furthering: 

I am like so sure!
Man the snow was nice today. (again)
Soft enough that landing from a jump is like a splashdown.
Sun is getting a bit strong though.
I think it will all be melted within a week.
It's about 80 degrees here today.
I guess I better start working on windmills again.
note to self:
stop writing notes to self...
kidding!
I'm not that organized.

One method of  release-and-receive:  glide

Finally, a peek behind the curtain at Tomas Saraceno's technical design, which looks like it will be only a working scale model, since a sparred cellular kite of this sort will not safely scale (and still fly) to the size suggested in the concept rendering (~150m tall), nor does the known budget fit such a monumental structure of advanced materials. A 20m scale is more probable. The schedule has slipped by a month. Secrecy is still high, with many detials withheld-

http://portscapes2.nl/nl/project-tomas-saraceno-solar-bell



A garbled machine translation of the Dutch text-

"The Bell Solar paints a science fiction-like image of a floating structure that is completely driven by wind and solar energy. The design is based on the model of the tetrahedral, invented by Alexander Graham Bell. Not only was he the inventor of the telephone, did he, driven by utopian thinking, important discoveries in the field of aviation and pilot construction. Saraceno blows Bells' model and brings new life into it, with the vision and knowledge of our time to the next level with the target people in the Solar Bell into the air to let go. The construction will fully wind drift and built according to the latest technologies in the field of lightweight materials and kite technology. For technical research works closely with the university. With the models that are built in August 2013 at the Maasvlakte several spectacular demonstrations." 

Dear Solar Bell development team,

The following is my initial rather pessimistic review of the Solar Bell from a "kite expert" point-of-view. Hopefully it will help to address well-known problems for a successful airborne architecture project. It will be quite interesting to see how the Solar Bell team ultimately resolves the technical challenges identified.

Please let me know if you want more detailed kite design input and direct assistance. Thanks for any corrections, clarifications, or suggestions.

Best of Luck meeting all essential requirements.

Sincerely,

dave santos
KiteLab Group


---------- Initial "Solar Bell" Safety and Flight Performance Analysis ------------.

The Solar Bell tetrahedral kite concept as shown on the Port Of Rotterdam website is either meant to create an illusion of great scale (perhaps with small mannequins and camera perspective tricks), or its a dangerous overly expensive and generally unworkable design. As is, the concept looks like it cannot fly without hurricane-force winds, or a dangerously weak structure.

An up-dated tetra-kite design can partially mitigate the problems, but the monumental scale shown still would not fly except in very high winds. The public claim that the most advanced kite design principles are being applied to this project is doubtful, starting with the choice of an obsolete and problematic kite type.


Even at 1/10th scale of what the renderings suggest, the Solar Bell will be hard-pressed to meet basic flight and safety requirements. It does not look like it can easily meet strict human-rated flight-safety standards, but might be climbed as a "dare-devil" stunt, with considerable risks of falling, or being injured by failing structure.

Bell's kites always suffered from excess structure and poor aerodynamics. The stick count and total length is roughly double to triple that of more ideal stick-kite designs, which means the cubic-mass penalty with increased scale is only aggravated. The stresses are not uniform, so an adequately strong uniform structure contains excess mass in the less loaded members (the Y-bridle as shown only adds extra compressive stress on the vertex it spans). Stick kites with maximum dimensions greater than about 20m are unknown, due to the applicable scaling laws.

The sails in a strict iso-dimensional tetrahedral kite suffer from excess dihedral and low aspect ratio. As poised in the rendering, the sails would also have excessive AoA, and will create as much (or more) drag as lift. The extra drag loading will add unwanted stress to the structure. The sail lay-out also inherently suffers from wake-interference and wind shadows. The flooring mesh will degrade lift and add mass. Solar-power will also add mass, and degrade flight performance, with poor orientation under most conditions.

The joints in a tetrahedral kite are a special design challenge, given the varied loadings across the structure, and the critical need to save weight.

The giant kite as shown might have strong oscillation modes in gusts, to the extent that the tether guy-lines and composite structure are elastic, and couple with the structural mass, as a spring-mass system. These motions could preclude humans walking freely within the structure. 
 
Common Rotterdam wind direction variation
http://www.windfinder.com/windstats/windstatistic_rotterdam_airport.htm


Composite structure costs will be very high with this design, compared to more modern alternatives (like soft kites). Decommissioning of the structure after the brief demonstration period is a design challenge. It would be sad if the elite Art world (SKOR) disregards its environmental footprint, when the quality materials could have had a far longer more effective life in a more optimal design.

Safe practical assembly and erection will be a challenge with this sort of giant kite, compared to kites that self-inflate and launch naturally. Its rather sad that no major advance in modern kite design is yet evident in this concept, given the available knowledge and talent at TUDelft.




----- Forwarded Message -----

A first challenge: 

Masses can be conveyed on trolleys in both directions on a tensed pumping line. To make progress, a line-grabbing cam-cleat can hold-and-release a pumping line by phase. Its a very similar principle to technical climbing ascenders driven in a mirrored frame-of-reference.

Such line-trolleys can do relay-transport across the sky with just one line.

CC BY NC SA

No other kite wing basis for current AWE R&D is so dominant as Domina Jalbert's Parafoil. This trend is evident in gliding sports as well, where parafoil-based paragliding quickly overtook hang-gliding and performance-gliding in popularity, and now dominates participation.

This success is due to several advantages over other gliders. The parafoil is the cheapest unit-lift, requiring far less capital investment. Slower flight allows less-expert piloting, with lowered consequence to most mishaps. The parafoil packs far smaller for transport or storage. It is more easily maintained and repaired or replaced. For AWES, the parafoil is more scalable, and continues to rapidly improve in performance and capabilities, outpacing technical progress in the other gliding methods.

A curious fact about the varied glider-sports is that they have a similar sink-rate, even as average flight velocity varies by a factor of five or more. This involves the spectrum of glider L/D ratios matched to the range of Reynolds Numbers. Two countervailing challenges to parafoil dominance in AWE are rigid-wings (including rotors) and single-skin wings. These opposed options suggest that the parafoil is all-in-all a good engineering trade-off. 

KiteLab thinking added two interesting twists to this picture. On one hand, large Mothra kite-arches operate in surface-effect, reproducing the the ram-air cell principle of the parafoil. In effect, the surface boundary is the "second-skin". Another promising constellation in AWES design space is a rigid wing sweeping suspended under a single-skin pilot-lifter, as an optimal wing hybrid. A ghostly "missing parafoil" occupies the flight-envelope gap between rigid and single-skin wing elements.

Further clues are found in data like gliding distance records. A performance sailplane can fly about 1000 miles in a "session" (limited by human-factors endurance). A hang-glider can do about 500 miles, and a paraglider about 250. One sees a basic logarithmic progression here. By computing cost-against-work-performed, one clearly flies more person-hours and even more person-miles-per-dollar with the lowly parafoil. Only if the hotter gliders can be flown over a far longer life-cycle can they (perhaps) close the gap.

Conclusion- We will likely see continued parafoil dominance in AWE, or dominance by closely equivalent ideas, for a long time to come.

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

Bias Disclaimer- I grew up alongside the early skydiving parafoil, and just learned that an old family friend, the late Bill Ottley, was quite close to Jalbert, as documented by the Drachen Foundation in its Fall Journal of 2004-

-------------------------------------------------------------------

Skydiving Legend Bill Ottley Recalls How the Parafoil Revolutionized His Sport

As skydiving icon Bill Ottley, of Washington, D.C., notes, people in his sport tend to think of today, of the 
moment; or maybe tomorrow, what’s ahead? But yesterday, or history, doesn’t interest them much.
Holder of degrees from Yale, Georgetown, and Embry Riddle, Ottley, a much-honored veteran of parachuting, has 
a more scholarly take. He knows and honors the history of the sport.
Ottley in the late l960s in fact flew down to Boca Raton, Florida, specifically to meet Domina Jalbert, inventor of 
the Parafoil. It was Jalbert’s ram air inflation concept that led to the steerable square parachute and to safer, more 
precise jumping. The new ‘chute had two layers of fabric and in flight air was ducted between the layers, forming a 
semi-rigid airfoil cross-section, enabling the freefaller to “fly” the ‘chute down like a highly maneuverable glider. 
“I wanted him to know the parachuting world recognized his genius,” says Ottley. “He had invented something 
basic to aviation. It was something that rearranged the lives and even the safety of an enormous number of people-
--hundreds of thousands of people around the world have skydived at least once, and here in the United States 
more than 40,000 people are active in the sport today.”
Ottley explains that “with the old round ‘chute, the sport skydiver attempted to land on a predetermined ground 
target using a kind of black magic. It was Mary Poppins floating through the air. The jumper had to calculate the 
position of the airplane, wind speed, and other elements. Then he took a deep breath and jumped.”
With Jalbert’s steerable ‘chute, the sport changed radically. Skydiving became more controllable and safer. With 
the square canopy able to move forward at 35 miles an hour or more, the jumper could now go where he wanted, 
instead of where the wind pushed him. He could challenge the wind. He could land on a dime, literally.
The Jalbert invention had a direct impact on Ottley’s own life. Having taken up jumping in l959 after a short-lived 
U.S. Air Force career, Ottley made 2,500 sorties in the early years and collected 20 broken bones. He cracked 
a fibula on his 13th jump, but was back at it as soon as his leg healed. This was the equivalent of a bullfighter 
receiving his first goring and coming back for more.
With the round parachutes, Ottley had 19 malfunctions and lots of crash landings, some really jolting. A malfunction 
meant his main ‘chute refused to open and he had to cut it away so he could activate his reserve parachute. And he 
had to do it in seconds. “These malfunctions were heart-stopping seconds,” he says. “There was a lot of adrenalin 
flowing. Some of the landings were rather hard.” He winces in recollection. With the introduction of the Jalbert 
airfoil ‘chute in l970, Ottley made 1,700 more jumps without a single malfunction and no serious injuries. “In 
fact, the control is so good I’ve landed on one foot more than once.”
“I did break six other bones,” he says, “but those came in other sports-----snow and water skiing, flying planes, 
gliders and balloons, riding motorcycles.”
After visiting Jalbert at his laboratory in Florida, Ottley saw him frequently at air events over the years. “We 
always talked. We were the old men. I found him a fascinating man, full of ideas.” Ottley like many others recalls 
Jalbert as unusually handsome. “He looked something like Tyrone Power.” Ottley adds: “I always held him in 
awe for his mind. He was an important innovator. Others took his Parafoil idea and perfected and commercialized 
it----- and cashed in on it-----but Jalbert was the inventor. He deserves to be honored for this.”20 Drachen Foundation Journal Fall 2004
Why did Ottley spend a lifetime pursuing skydiving as a sport? He recalls himself as the guy with the thick glasses 
and lack of athletic skills who learned to do something excitingly different. “I’ve always liked the adrenalin rush that 
goes with jumping. Then there is the camaraderie of the sport. That’s the big thing. You get to know an enormous 
number of extraordinarily likeable people, a wonderful collection of all-American type A personalities.”
Ottley spent his life working in aviation and has a long and impressive curriculum vitae. Among his many jobs 
and honors, he points to being U.S. delegate to the International General Aviation Committee of the Federation 
Aeronautique Internationale, based in Europe, as being one of the most long-term and meaningful. 
Now 74, Ottley has long since had to give up sports because of an old skydiving ankle injury suffered in a night 
landing that now causes him to hobble and use a cane. “It was my error and not an equipment failure,” he says, 
with his customary straightforwardness.

for those of you into enough kite detail
http://youtu.be/IjIEpc6YKEs
A video about replacing bridle pulley line for surf kites with a round profile 3mm rope line.

Should be a winning combination with friction ring pulleys like...
http://www.drtuba.eu/Other-Parts/PULLG/Bridle-Pulley-Guide.html