I can't read all the labels; some are obscured by the Yahoo panels in my client.  From what I see, it looks as if the blades would see more wind if the lifter was on the tail end.

Thanks, Bob.
Right click and get properties of image. Copy URL of properties and get
http://www.energykitesystems.net/JoeFaust/AWE/AWEselsam1everupfanbelt.jpg
Paste in a fresh window to see image only.
I will make here a tiny URL in the case the absolute URL breaks in e-mail:
http://tinyurl.com/imageLIFT333

Cheers,
JoeF

Thanks.  I see you anticipated the benefits of a tail lifter.  The front lifter seems to serve more to shorten the "fan belt" portion.  Assuming that pulleys suitable for kite string can be made, the weight penalty is just a second, return run of string.  This is probably much less than the weight of an airborne generator and a conductive string, but I'm not sure.  The lighter options would probably be less efficient, though, and the string rig can be quite good.  The drive efficiency could probably be kept over 95%.  It would be a good application for spectra "string."

Joe and Group,

The tensarity is hydrogen/helium filled? At the front a ninety degree gear, how to make fool proof against jammin up.

Dan'l

Doug,   Prepare to be further surprised by some of the great turbine talent still unknown to you on this list. They know that your choice of power v. diameter is a ridiculous measure of overall potential & notice that you simply ducked the issues raised on this list about torsion tube scaling, bird/human hazards, & so forth.   The NREL booth had a great clue for you- Take an Air turbine (a small-scale "gold" standard") & put your blades on it to match its performance at a lower capital cost (<100$). Pay DanF to fly both turbines (control & experimental) side by side for a couple of years & monitor output. Impress NREL & the pros that way.   Maybe we can agree on the foolishness of ranting about a defective ground turbines on an "airborne" wind list? DaveS   PS Hint- put a spiral stripe on your torsion tube to alert birds.

This thread is invited to be focused on turbulent entrainment along with findings impacting airborne wind energy conversion systems.  The thread may persist for years, as long as someone is interested.

That was a bit brief. Here is a step forwarding.

The drag topic, the variDrogue topic, the complex flows along Selby cabled beads of counter-rotators, the complex centerless helical blades of the SpiralAirfoil, the interferences and surfaces of vortices involved in the serpentine leeward stacked rotors of the Selsam favor, and much more in AWE all seem to invite turbulent entrainment study. Messy air energy mining with airborne works seem also to invite more attention on turbulence. The BWEA main photo with post-turbine turbulence seems to beg airborne replacement.
Turbulent entrainment and AWE
is title of new folder to support this thread.
http://www.energykitesystems.net/TurbulentEntrainment/index.html

Professor Robert Briedenthal is one of the leading experts in this field. For me, there is ever very much left to learn.

Lift,
JoeF

Here's a link to a wind energy article of interest:
 
http://www.energypulse.net/centers/article/article_display.cfm?a_id=2184
 
 
Harry

---

New! Open Hotmail faster on the new MSN homepage!

--- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...
Yes, this group's leading posted preface:
===============
TARGET:
RAPID DEVELOPMENT
of
practical AWE
===============

Good focus. Thanks.
So, I will not press to continue this thread in group space.

However, the folder of files for this thesis topic will remain open at EnergyKiteSystems.net for organizing inputs that may arrive from anyone on turbulent entrainment; the study over AWE will no doubt be going on for years to come. It is important for AWE to rapidly install some practical well-working and well-measured systems.

JoeF

Drag doesn't help performance but it can help stability. Certainly there is a trade between trim drag and stability in airplanes. I would expect it to apply to kites also.

Check out the Whalepower design that marine scientist Frank Fish has come up with.  It improves the efficiency blade rotors and plane wings lift by 20%  The leading edge of the pectoral fin of the Humpback whale was modeled, and disovered that by combing the airflow going over the wing surface has very beneficial results.  One is releasing drag, and the other is the quieting of the spinning rotor blade:

Bear in mind that these are essentially anti-stall devices.  They let us operate with less wind, but there is not much energy to extract at such speeds.  Meanwhile, there could be an increase in drag, if only because of the difficulty of construction, at the most productive wind speeds.  

Re-posted to include news about bumpy, whale-inspired leading edges,
truncated mysteriously:

Bear in mind that these are essentially anti-stall devices. They let
us operate with less wind, but there is not much energy to extract at
such speeds. Meanwhile, there could be an increase in drag, if only
because of the difficulty of construction, at the most productive
wind speeds.


Re: Drag - the parasitic drag of lines normal to the wind can be
halved by adding a simple, semi-rigid vane to the trailing edge.
Much greater reductions are probably possible with shaped fairings or
molded, unidirectional lines.

Bob Stuart

Thinking over alternatives to leading-edge bumps as a way to take advantage of lower winds, I wonder if anyone plans to adjust the size or number of the kites they loft, according to conditions?  With 3 sets of sails, the same generator and lines could be run much closer to capacity most of the time.  How about kites that change shape or size, as necessary?  Presumably, a roller-furler could be fitted to a flexi-foil.  Or is spilling wind close enough to optimum?

Spilling wind - french reefing to a sailor - generally is hard on structure. It usually results in luffing and unsteady loads. Variable geometry - flaps spoilers or furling works well in airplanes. Basically a weight trade. Is the extra weight aloft worth the benefits?

Is this the most efficient design for a lifter kite to use for this purpose?  http://kap-man.de/e-manlifter.htm

---

To: AirborneWindEnergy@yahoogroups.com
From: christopher.m.carlin@btinternet.com
Date: Wed, 21 Oct 2009 20:14:49 +0100
Subject: Re: [AirborneWindEnergy] Variability

 

Many years ago in my Hang Gliding days, someone was producing a fairing coating for the cables that did just that. I don't recall the name, place or date of such product or how it played out but something to look into.
-brooks

"French reefing" to an *English* sailor. No doubt "English reefing" or
similar to the French. :-) Often called "scandalizing" the sail in
America which somehow carries the same "naughty" or "foolish" theme as
the "french/english" thing. I'm referring, of course, to the various
"french letter"/"english letter"; "french disease"/"english disease"
etc, etc--which have gone on for centuries between the two cultures.

Funny stuff.

Dave

On Wed, Oct 21, 2009 at 12:14 PM, christopher carlin
<christopher.m.carlin@btinternet.com

Bob,   You are right to suppose a "quiver" of kites maximizes AWE capacity. There is no one-kite-does-it-all, but many are going that route. Varying the size & number of kites is quite useful to adapt to load, location, season, & daily conditions. Stored quiver stops the wear clock, its flight hours that count.   Existing highly variable wings are too heavy for current kite applications, but similar wings will someday rule the jet streams. Passive variability helps, like elastic TE bridle lines, or membrane decambering when a LE spar bends, like a mainsail mast does in a blow.   The varidrogue approach to variability offers a huge drag range, close to 100/1, Common depowerable kites have a variability during sweep around 5/1. Varying sweep from parked high to sweeping wide depowered is around 10/1. These guesstimates come from deep self-hypnosis sessions, then i have to mop up all the drool,   daveS   PS How come the English & French always get the credit? They should call it Mexican Reefing ;^)

How about this concept of a kytoon, where the wind makes the tail flap to create electricity that is sent down a dual-conductive tether!

They do my friend, they do. There's also the Mexican takedown, where
the sails are dropped in the water, then run over... There's also the
Samuri takedown (Cut the rope. Really!)

But the French/English thing seems to dominate on the European side of
the pond. They've been playing this game longer than we have, you see.
;-)

Dave

Hi Darin and Group,

Love it, the shape of things to come.

Dan'l

This was intended for the group:

This letter from Doug Selsam was intended for group in this thread:

fromdougselsam <doug@selsam.com

dateThu, Oct 22, 2009 at 8:38 AM
subjectRe: Open Letter to NREL and ARPA-E
mailed-byreturns.groups.yahoo.com
signed-byyahoogroups.com

hide details 8:38 AM (2 hours ago)

Hi Dan:
Here's a link to the California Energy Commission Report on my research.
http://www.energy.ca.gov/2007publications/CEC-500-2007-111/CEC-500-2007-111.PDF
Data was independently taken by Windtesting.com

I hope I clarified that no one rotor will beat Betz and it is futile to try.  But what is important is that EFFECT is the same insofar as it affects the commonly-applied interpretation of Betz: previously, Betz was interpreted as power being strictly limited by rotor diameter.  If you look at just my SuperTwin(TM) as a start, I've shown how to bring the rotor into the third dimension, abandoning the prison of the circle,  and instead having the projected area of an offset cylinder, which can be as long as you want.

My contribution is to combine the power of many rotors, using a single moving part, limited only by the torque capacity of the driveshaft.  Previously, anyone would have said a 4-foot diameter turbine can only get 400 watts at 30 mph, due to Betz etc.  That is usually as far as it goes.  Tell any wind person a diameter, and they will spit back a rated power level.

So when I say "I beat Betz" I am saying it with a wink. 
We "apparently" beat Betz, according to the common, habitual interpretation of Betz.  One could say we beat Betz by cheating.  Like a rotor can now call all its friends in for help, as in a tug of war, one could recruit all his friends against a single adversary.  So please don't get too literal on me when I make a comment like "We beat Betz".  Don't forget the "wink wink" part.

The fact is, understanding Betz is where the whole thing began.  That is the first difference between someone who "gets it" and the many who haven't established a background of understanding wind energy.

Again, nice book.  I have been recommending it.  And as you know, I admire your finely-crafted turbines. :)
Doug Selsam
http://www.USWINDLABS.com
P.S. It seems hard to believe you would be working on flying turbines, since you seem dedicated strictly to the exact Hugh Piggott design.  I'm curious, what is your interest on this list?

Funny this topic came up, Brook's & i actually pioneered this genre with the legendary Austin Robot Group starting in the late eighties & made many fish-like micro-LTAs. The incredible weight discipline required for micro-LTA nicely preadapts us for good AWE.   I did not find a link to one of many fish-tail variants, but this flapping-wing/running-leg model gives an idea of the work, still hardly surpassed after almost 20 years. Maybe Brooks has more links or can port some legacy video. Sadly, we learned helium is a very marginal basis for aviation.   www.robotgroup.org/history/ projects/ roboblimp.html

This post is from DougS sent through group moderator and meant for the group view:

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

fromdougselsam <doug@selsam.com

dateThu, Oct 22, 2009 at 2:43 PM
subjectRe: Selam's Missing Insights
mailed-byreturns.groups.yahoo.com
signed-byyahoogroups.com

Hi DaveS:
I try to not post on these lists anymore, though it is endlessly tempting cuz it can get fun, especially when the flame wars start :).

The bottom line is, talk is talk, and only talk.  As long as we are on "the all-talk format", your theories are equal to mine, your opinions that my opinions are bunk have equal weight, and any drag machine has as much power as anyone wants to wish for.  Words are only words.  It is when you have to stop talking and build a machine that not only makes power, but does it economically, and is still there (survived) months (preferably years) later, and not destroyed by the first big storm, that the rubber hits the road.

All I tried to point out is I see no evidence that anyone here (mostly) knows what they're doing (yet) for the most part.  That is not to say they aren't fine people, or that they won;t learn with experience and time, but an amateur is still an amateur.  I did also say "We all start out as beginners - I did too."  I had the veterans telling me how dumb I was to suggest more than 3 blades, per rotor etc., just like beginners do today.  I had to listen to the veterans.  I remember the day I dropped from 3 blades to 2 per rotor and saw my power increase a LOT.  Who knew?  I slowly found that the veterans knew a lot that I had no clue of, or just didn't want to believe.  One cannot adequately describe the functioning of a high-speed rotor in its power band - it has to be experienced to be believed. (wow!)

I can see that what I offer as facts and solutions is just more fodder for those with too much time on their hands to endlessly try to dissect and shoot me down.  That's OK I am used to it.  Anyone actually accomplishing anything is fodder for the gristmill of commentary.  No problem, just spell the name right. :)

Here's the deal with energy:
You need to generate electricity at 4 cents/kWh to improve on what is already available.  Keep that in mind. A 100 kW machine makes $4/hr in a full wind, less than minimum wage.  Including wind variability, it makes only 1$/hr (one dollar per hour), over the years, in a class 5 windfarm site.  Minus expenses, such as initial cost, and minus operation and maintenance (O&M) costs.  How much is left as profit?  How much dacron and helium will that replace every few weeks?  Put your financial calculator to that, K?

Now I don't hear anyone on this list saying:
"We HAVE a flying wind turbine and HERE is how much power it makes."
All I hear are hypotheziations by people mostly talking about the same stuff we have heard all the beginners talk about from day 1 in ground-based regular-old traditional wind energy.  These are the armchair inventors who speculate but never build.

If you think me saying I see no evidence that anyone here knows what they're doing (yet) then show me who does?  Where is the machine?  Do you have a link?  Maybe they are just lurking and not posting?
That statement is not an insult at all, just an observation that there is a learning curve ahead for most people.  And someone like Dan from Otherpower.com is the exception.  If you listen to people like him, there is a lot to learn.  He is kind to teach what he has learned.

Like I tried to point out, the beginners interpret someone who tries to give them the facts as insulting them.  Of course their design "must" be good, in their mind, and when they encounter someone with experience that can set them straight, they see how much work they have ahead, they don't like it, and are resistant.  You can look that up in any book on wind energy in the first chapter where they steer the reader away from  drag machines.  They also talk about how irate the beginners get when presented with any facts.  That is also "standard" and well-established in wind energy.

I think I have had enough of the all-talk format now.
I don't want to spend my time ruffling feathers here, if that is all that is gonna happen.  So I think I will bow out now and just observe.
If anyone has any flames to throw my way I won't respond anymore.

Please let me know when someone has something - anything - up and running in this "industry"...  Personally I am rooting for SkyWindPower as I believe that concept is solid.  Makani also seems perhaps to have some potential for having some future promise, (cautiously stated) given enough time, (lots of qualifiers) although as with "whale bumps", anything sounds good if all you look at is a press release or 1 or 2 facts, in the absence of ALL the rest of the facts.  But I don't see them on this list.  Are they posting?  They may have figured out, either you have something, or you don't, and all the talk doesn't change that.  So why talk?  And invite flames that they will be tempted to respond to?  Just build! :)

And I like the kite ideas as long as the kites are moving fast - drag versions I am not convinced will ever pan out.  I think a lot of concepts have a lot of promise and certainly the sky is where the real wind is found, but the devil is in the details, as they say.  Show me the machine!  OK that's my 2 cents and thanks for listening.
:)
Doug Selsam
PS a really stewpid website that I never finished, about vertical-axis scam drag machines, a few years back:
http://www.WhyAreYouSoLame.com

How many here are going to Chico? Real AWE, real working prototypes, real science. Anybody?

Suggest that this thread stays on its topic. Follow, post, and discuss matters related to HAWP Conference 2009. Keeping a thread on topic may form a strong group dynamic. Please keep cutting out duplicating full prior posts as a reply is made; we can do it!

DaveC just asked who in this list is going to Chico, CA for the conference.

I'll be there.

DaveL

I'll be there too:

JoeF

This post is from Doug Selsam for the group for this thread sent through moderator:

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

fromdougselsam <doug@selsam.com

dateThu, Oct 22, 2009 at 1:22 PM
subjectRe: Whalepower (Whalebumps)
mailed-byreturns.groups.yahoo.com
signed-byyahoogroups.com

Glad to know my dripping paint has a purpose. ;)  So the drips have a name - whale bumps - who knew?  Maybe we should run some tests, with the bumps and without, and verify that 20% number.
Beware of press releases substituting for real research.  This idea has been around for awhile now and I haven't seen any results except for a lot of press, but no examples of any turbine talking advantage of whale bumps.

You hear stuff like this all the time.  I'd say concentrate on getting something working at all, then improve on 1000 years of airfoil fine-tuning later.  Turbulators have been around in aviation for many years, and have the same effect.  If there were any true advantage to whale bumps, would they be "stick-on bumps" applied over a unidirectional fiber skin?  Or would we expect to waver our otherwise straight unidirectional roving layup?  Oh forget it I have probably lost most of the audience by now.

Anyway let me just say that there is room for endless speculation in this field that combines 3 invisible forces: wind, magnetism, and electricity.  There are lots of people on these lists who live in their mom's basement and have all day to discuss a press release as though it were a fact etc.  Let me just say that you have to have your feet on the ground before you will ever make any progress in this field of flying wind turbines, or any kind of wind turbine, or really any machine period.

Much of what we read on these lists is as though we were talking about internal combustion engines and someone says they want to introduce a lot more fuel without more air to go with it.  That is like saying you want to increase the solidity of a rotor by adding more blades, or a continuous blade.  The more blades you add to the circle, the more you bog the machine down.  By that time, you are running the engine with the choke on all the time, and you have a drag machine.  People get tired of having the choke on and want to hit the power band, so they get rid of 96% of their structure and find, lo and behold, less blade = more power.  Fly blade, fly!  Then there are the whale bumps.  Here's a limerick:

"A girl was quite down in the dumps
from having developed whale bumps
The chafing of her thighs
was a sight for sore eyes
Especially when walking with pumps"

:)
Doug Selsam
P.S. Press Release: Intergalactic SuperPhD ultra-scientist Frank Whale has developed Fish Bumps for blades!  No self-respecting fish in his right mind would be caught dead without fish bumps.  So get witgh what is hip, and learn a lesson from your ancient ancestors: Fishpower.  Seeking investors.  80% extra power is "projected"  - Google? ;)

Dear all,

I am the organizer of the HAWP 2009 conference and I hope that all of
you will come. This will be the first time that the airborne wind
energy people can get together in a professional environment and show
each other what they got and how they got it.

There is still time to register here:
http://www.hawpconference.org/registration.html

Note that the $125 registration fee includes: a dinner at the Sierra
Nevada Brewery, home of the great Sierra Nevada beer; 2 lunches; 1
breakfast; registration to the This Way to Sustainability conference
at Chico State (http://www.csuchico.edu/sustainablefuture/
conference/), and transportation from Chico to Oroville.

Not to mention that Doug Selsam has promised us to show a demo of his
device ...

Regards,
Cristina
*****************************************************
Cristina L. Archer

Assistant Professor
Department of Geological and Environmental Sciences
Holt Hall, Room 312
California State University, Chico
Chico, CA 95929-0205
Tel. +1 (530) 898 5618
carcher@csuchico.edu

Consulting Assistant Professor
Department of Civil and Environmental Engineering
Stanford University
Stanford, CA 94305
http://www.stanford.edu/~lozej
lozej@stanford.edu
*****************************************************

Attachments :

darrieuskite2.jpg

---

New Windows 7: Find the right PC for you. Learn more.

Hi Peters and the group,

Crosswind accelerations are not a problem and cannot be avoid when a high part of the fly window is used.The cyclic hydraulic storing smooths the production before entering to generators.

Half-turn must be quick and with a low radius:so the driving device must be near or on the kite.When I try crosswind trajectories (with 2 or 4 lines 4 m² or 9 m² kites,ratio LD = 4 or less),there are no problem during trajectory.With high ratio LD (8 to 12 and more if possible),the speed is higher,and so the kinetic energy of the kite:so high speed can be an element for trajectory kite stabilisation.

OrthoKiteBunch with only one kite is OrthoKite,with orthogonal transmission between lines and double lever in alternance.So first trials will determine gains of useful tangential strengths.

Pierre Benhaïem

OrthoKiteBunch 

 

 

 

(for my precedent message  reading Peter (not s).

Experience of drag with solar balloon jumping 

After jump the 200 N lift balloon and me go down,then the balloon goes on (inversing kinetic energy):I must pull the balloon for 1/5 of descent;the difference is balloon drag.Such a balloon as AWE would have a valve to the top for cyclic descent.A 400 m3 balloon produces 1800 J/10 seconds.Little power for little cost (10 kg of HDPE).

Pierre Benhaïem

OrthoKiteBunch  

If this design is for an incredible art exhibit, it is really cool.  Though, if you are wanting to make a practical electricity-making device, it is way too elaborate.

---

To: AirborneWindEnergy@yahoogroups.com
From: pierre.benhaiem@orange.fr
Date: Fri, 23 Oct 2009 16:52:13 +0000
Subject: [AirborneWindEnergy] Drag

 

Attachments :

After the posts of Joe and others, I have been inspired to re-draw the kite, as well as the "dual H-Darrieus" assembly, re-scan it and send it to you here.  So, I've placed all of the pertinent information that I've found, into this one email.

 

It’s a more practical design than the last posted drawing, because it utilizes an H-Darrieus rotor unit with only two blades.  Here is some background information on it:

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

 

Instead of needing an elaborate tower to mount it all on, now it's held aloft by a hexagonal lifter kite:

http://www.cradleofaviation.org/exhibits/dream_of_wings/marconi/

http://www.kites.org/tmr/baden-powell_eng.htm

http://www.kiteplans.org/pln_120/

http://people.zeelandnet.nl/kitepassion/Baden.htm

To assemble this very stable kite, and then send it aloft to only 100-200 feet, would probably take as much effort as setting up the family tent!  Then, an abundance of electricity can be made.  

 

By changing the design of the contra-spinning "dual H-Darrieus" rotors to have only two blades per unit instead of four, it becomes simpler to assemble, and actually, as I have just discovered, more efficient! 

What this wind energy engineer, Doug Selsam,http://www.superturbine.info/, has recently written about, makes a lot of sense.  Even though he speaks of propeller blades, I believe that it can also be translated over to H-Darrieus blades as well.  Basically, adding more blades than the original two, only leads to more drag:

 

“I had the veterans telling me how dumb I was to suggest more than 3 blades, per rotor etc., just like beginners do today.  I had to listen to the veterans.  I remember the day I dropped from 3 blades to 2 per rotor and saw my power increase a LOT.  Who knew?  I slowly found that the veterans knew a lot that I had no clue of, or just didn't want to believe.  One cannot adequately describe the functioning of a high-speed rotor in its power band - it has to be experienced to be believed. (wow!)”

 

This company, Carbon Concepts, who appear to have a superior design to all other 'Darrieus'-style wind power generators.  They do use four blades, but that can easily be edited back to the original 2-bladed system, from the 1921 patent.  They also manufacture their own designed electricity generator.  http://www.carbonconcepts.co.uk/

 

They also are set up to fabricate any shape and contour of a blade that one may require.  I was studying their present carbon fiber blade design, and it came to mind that the Ultralight trike wing blade shape, that I've come across, may even turn out to be even more efficient.  This wing is shaped in such a way as to most likely increase the leading-edge pull, or lift.  (see attachment section^)

 

Then even experiment with attaching those"bumps” on the leading edge of the bladewings.    Why not?  It may just turn out to be all that marine scientist, Frank Fish, says that it is.   If the Humpback whales are doing it, it must be good, eh?   There has  to be a particular reason why these tubercles exist on the leading edge of their pectoral fins.  And, I believe that he has discovered why.  

They migrate over 5100 miles.  These boney  tubercles (that’s right, they are part of the bone structure), comb the water, to make it more fluidic, and less chaotic, as it flows over the fin.  This means that more of an organized slipstream is created.  So too, one might as well place this “Whalepower” technology on the leading edge  of each carbon fiber, V-wing shaped blade.   And then receive 20% improvements, according to the tests they’ve done. 

 

Here is a review made of Carbon Concepts present-day carbon-fiber blade unit: 

 

"Carbon Concepts, UK based designers of lightweight composite structures, have developed a near silent vertical axis turbine for domestic and industrial use.

 

The company have developed carbon fibre technology for a variety of industries and applications, and applied their experiences with aerodynamics and composite construction to create an innovative vertical axis turbine which claims to offer an almost silent operation, even at high speed and load.

 

The vertical axis machines are generically quieter than traditional wind turbines, with the novel design of the blade tips rendering the turbine virtually silent even at the highest speeds. The company do credit outside assistance, with much of the aerodynamic technology being built on the electrical generator and aerodynamic expertise from the University of Durham.

Most of the functionality of the turbine is based around the use of carbon fibre, a material which has added fatigue resistance, with many other vertical turbines having failed through fatigue in similar aluminium structures, according to the company.

 

Testing has confirmed that, even at high speed and load, the rotor is effectively silent, and attempts to measure the noise of the rotor showed that perceived noise was dominated by the wind and adjacent trees.

 

The turbine also has a carbon spar made with glass fibre skins, which is required to keep the fatigue levels below the endurance limit, providing a virtually infinite life.”

http://www.carbonconcepts.co.uk/

 

As powerfully-efficient as Doug Selsam’s  multi-rotor system is,

http://www.superturbine.info/, one needs to also consider having a multi-propeller noise factor, which would be much greater than that of an a multi-unit H-Darrieus system. 

 

Granted, it may not even be close to producing the same amount of power-output of this multi-propeller system, yet the trade-off would be its quietness and portability.  Four detachable Carbon fiber V-shaped bladewings, and two rotating hubs, with an electricity generator in-between, with a slipring assembly below it.

 

The other advantage is that these “contra-spinning”, H-Darrieus assemblies can be vertically-stacked in numbers, while hanging beneath the kite string pulley.  The constant tug from the spring-loaded spool reel, is fastened below to the ground. This spool may be located about 100 feet away from where the trailer-mounted kite tether, hand-crank spool is located. 

 

The multi-propeller system has props spread out on a relatively horizontal, spinning axle.  So in that regard, it needs an elaborate “yawing” rudder fin to stay pointed into the right wind direction.  The simpler, H-Darrieus assemblies will continue to spin, no matter what direction the wind is coming from.

 

I would also venture to say that, having vertical-spinning, carbon-fiber blades would be more benign to flying creatures.   As these units get larger, the chaos vortex turbulences also have to be accounted for.  There is already trouble with bats’ lungs exploding, from flying in the downwind vicinity of a wind farm. 

 

Multiple spinning blades mean a smaller, more concentrated, trailing vortex street. http://en.wikipedia.org/wiki/Kármán_vortex_street

That means a smaller, more intense area of low pressure turbulence, is created.  To maximise its efficiency and capture the “fresh wind”, these many spinning blades are tilted, upon its one long spinning axle.  So, the area of downstream chaos vortex turbulence is magnified upon that one horizontal axis.

http://www.speakerfactory.net/Truss.jpg

 

Stacked H-Darrieus, contra-spinning units, would tend to spread its downstream chaos vortex turbulence along a vertical axis.  This means less of a concentrated, low pressure zone in one area.  This is better for the bats, and preventing the barotrauma from happening.

 

Is it really about making more wattage than the next guy’s design, or is it more about efficiently utilizing the amount of power that is being created?  That is, highly-efficient appliances, which would be used on a daily basis (i.e. refrigerator, lighting, computer, water pumps, electric vehicle).  This upgrade to appliances that use micro-power, could offset a lower wattage output of a not-as-powerful, yet more benign, wind energy harvesting system.  ~Darin

p.s. There are also some .doc and .pdf attachments to look at.

 

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Simplistic assertions against aerodrag were expressed on this list. DaveL replied with a fine explanation of L/D v. ROI as a predictor of market success. The following mock FAQ expands the idea that some Drag is golden, especially for kites, where low weight usually counts more than high L/D. ===========================    How is more lift extracted from a wing by adding Drag?

Several companies seek to put flygens at high altitude. Expert opinion sees Sky Windpower as the most promising of this bunch. They have the best engineers, the longest trackrecord, the best studies, the safest design, & have been by far the most generous & open with public information.   But the flygen approach has daunting challenges, particularly the safety-critical issues of placing high mass at high altitude & practical concerns of managing a long conductive tether. Remote unobstructed siting mitigates the risks & is still a vast opportunity. Vigorous research is justified. This note addresses conductive tether issues in particular; problems & possible solutions.   Mcnaughten & associates calculated years ago that a conductive tether flygen would often leave miles of cable laying on the ground, nevermind runaway. This would be terrible around populations, especially across powerlines or highways. KiteLab's tether experiments support these concerns.    When tether force slacks a heavy cable sags very quickly to the ground, often faster than a normal reel or motoring aloft can react. Thicker conductive lines don't just add drag, but negative lift by negative AoA. Imagine how much 20km of downforce amounts to on top of the high weight of a flygen. Aluminum is the lightest conductor for its electrical capacity, but fatigues rapidly in high flexural cycling like reeling-unreeling. Copper is quite heavy & the limited supply is needed for global generation capacity, as Brooks pointed out.   Possible Solutions-

I am voting to use "a" instead of "the" for small fixed location solution.

The statement:
The alternative would read:
"DanF is right that a tower is a solution for a small fixed installation."

What tickles this tension?
I am assuming that by "tower" was meant the hard-structured tower with compressional members with or without cable stays for holding rotors of various number of blades (1, 2, 3, 4, etc.). I am not ready to quit on searching and finding neat ever-up AWECS (EU-AWECS) for the sector that might be covered by "small fixed installation." For one, I sense we are yet in the infancy of putting on the choice table the possibilities.

Your two-line tether tension-only tower and your three-line tension-only tether tower are yet incubating; out of those may come something strong for small fixed installations. Also, the kytoon continues to be improved and make intrusions into AWECS designing that may be fit for small fixed installations. And there will be the wrestle with just what "small" and "fixed" means per site and need. And I keep open that the three mentioned avenues for tension-only towering may be a beginning part of a short-list of AWE solutions for small fixed installations.

It will be interesting to see total system cost per kWh that may come out of competing solutions for small fixed installations. Total system cost will include operator's time, average casualty, replacement smoothing, property value changes from installation fact, repair, maintenance, etc.

The hard towered evolving is also not finished for small fixed installations. AWE infancy will grow up. Then we will see wider choices.

JoeF

JoeF,   Re: small tower solution, i was speaking for gentiles who are not "tako kichi" (kite crazy). Flying kites from towers is a good compromise, no?   Here is a fix for sudden conductive tether sag-   Neat Volcano Application   A tall volcanic cone with a top crater is ideal terrain for anchoring large scale AWE. Simply bore anchors thru the thin crater wall & bring the cables together in the center. An AWE array can launch & land suspended from this center. Several great volcanoes reach to around 15000 ft not far from large populations, For example, Popocatepetl volcano could serve as a high altitude base to tap the subtropic jet stream within sight of Mexico City.   -------------------------------------  Whoops. last post failed to mention problem of high conductive losses of long flygen tethers.

1 of 1 Photo(s)

Hi
Thanks to Christina for the invitation to run a demo airbourne Superturbine(R) at the upcoming HAWP conference. As someone who has been waiting for such an event for my entire life, it would seem I should certainly attend.

I spent the weekend rebuilding the Popular Science "Invention of the Year for 2008" machine with 25 propellers - it was built as a "disposable" demo and was damaged in a crash landing.
Every propeller was handmade and many had to be replaced, as do sections of driveshaft.

I'm also fabricating a few demo machines for an upcoming TV show, answering phone calls from turbine customers, filling orders for wind turbines, electronics, inverters, working on patents, providing replacement parts, etc.

I've been advised regarding the HAWP conference that:
1. there is quite an extensive infrastructure of towers etc. onsite
2. The windmaps show this area as a class 1 wind resource on the scale of class 1 - class 7. (low wind area)
3. There are some roads we might drive down for moving demos if there is no wind.

Now one thing that anyone in the wind energy industry can tell you, there is nothing more frustrating that having large groups of people standing around for days waiting for a slight breeze that might coax the rotors into spinning. In fact the unwritten rule is a new turbine installation will shut down all winds for at least 3 days :)... That's why we normally try to do demos in class 5 or 6 windfarm areas. Even then, it is not unusual to have the special day, scheduled far in advance, turn out to be calm.

There is a solution: A wind tunnel. This means you hold the turbine still and attempt to move the atmosphere through the turbine. Like the old joke about screwing in light bulbs (acquire a budget that will allow the scientists to rotate the building around the light bulb), this is a solution only a scientist could love, since it allows them to continue to sit in their chair and do nothing, while lamenting the prohibitive cost of a wind tunnel, or the unaffordability of time in an existing tunnel.

Another solution is to mount your turbine on the front of a vehicle and drive it through the atmosphere, but scientists cannot seem to fathom such simple solutions that require them getting out of their chair and, say, ordering some steel and welding it into a mount. The cost is $100 instead of $100,000,000 and the results are superior.

It makes one wonder: maybe scientists never learned to weld - that might explain it. So you won't find scientists out driving around taking data and doing demos - they instead stay safely in their chair and if questioned, tell you how many years they have been sitting in a chair now (degree & "experience"). Perhaps a welding class rather than 4th prder differential calculus would help... but I digress

For this and related reasons (excuses) I don't expect to see NREL nor ARPA-E, with their billions of dollars, bringing any machines to demo at the conference (surprise me). No, that task would probably fall into the hands of all those little inventors scattered across the nation that our president said would now be funded and have the government's help, however we are left twisting in the wind as usual.

So the question is, if I can build (or rebuild) the PopSci machine, or another, longer and more powerful machine with factory propellers, and get it up there, 10 hours drive North, will there be any wind?

That other solution (remember the light bulb joke) is to save a lot of effort by moving the turbine through the atmosphere (like screwing in the light bulb by turning the bulb - gee ya think?), using a vehicle.

So, should I bring a turbine I can tow using my "inside-out wind tunnel" also known as my van with over 300,000 miles on it, with a rack welded onto the front that holds wind turbines?

Next choice: How to support the upper end? My popular Science 80-foot long flying turbine with 25 propellers weighs about 30 lbs total, so we need about say 20 lbs of lift for the upper end. Turbulence and wind thrust want to push balloons to the ground, so I'm sort of leaning toward balloons AND a kite, but which kite and which combination will depend on whether there is any wind, or whether I have to bring no only the machine, but also the wind itself.

I have a 9-foot lifter kite but it is not suitable for strong winds - mine is merely a tourist-grade recreational kite. I'd say its design lifetime of a few hours has already been exceeded.

Trash bags make the best balloons for the cost. Each 55 gallon bag will lift about 6 ounces.

Meanwhile I am so over-the-top busy with customers ringing the phone off the hook, and nobody to handle it all but me (no help from NREL & ARPA-E? Hard to believe, no?) that I am at the point that every day is just solid emergencies and that includes Sundays and Holidays.

I'm wondering if anyone else is bringing any:
1. Kites
2. Balloons
3. Combinations of the above
to tether to the upper end of such a 30-lb, 80-foot long turbine with say 25 three-foot hand-carved wooden propellers as seen in popular science (article 10-times the turbine).(?)

Also, is anyone bringing any heavy-lifter kites that could lift one end of a 120-foot long steel driveshaft, with factory propellers - say 100 lbs or more?

I realize these questions are difficult to answer without stating a wind speed.

I have gotten to the point that I am blowing off ALL grant proposals, conferences, etc., as I simply HAVE to make progress and since ARPA-E, NREL etc, and even Google, BP, etc., have taken so much of my time for no result I am really in a pinch now to realize that I have to do it ALL myself while trying make up for the time lost time to the funding deniers.

<pause - woops had to answer the phone - another turbine order - can I have it to you how fast?
OK I'm back, away
<wait the phone again - whoa - girlfriend - no time for that either - need a new phone battery - wait need to pay the electric bill too...
OK wait I'm back again.
Now as I was saying, it is a LOt of work being the only one pushing ahead in this field of multi-rotor turbines, especially having to do so much of it myself. I just received a press release e-mail from ARPA-E a few minutes ago - they just funded 20 companies for 150 million. Wow impressive. I am still holding the bag as far as I can see.

Anyway, bottom line is I am scrambling to see if I can get up there for the conference, but I just don;t know, becuase everything seems to turn into one more unpaid assignment for Doug, yet I have only 2 hands and half-a-brain, not enough help, and, though now well-funded, I am still the only "shot-caller" on board and so I just don;t know what I can pull off by then.

Any info regarding probably windspeeds, others' apparatus available for lifting, etc., would be eagerly appreciated.
This conference is long overdue in my opinion so thanks for having it and thanks for the invitation, to whomever has worked hard to make it happen.
Thanks for your time
Doug Selsam
Selsam Innovations / Superturbine Inc. / USWINDLABS
2600 Porter Ave. Unit B
Fullerton, CA 92833
714-992-5594
http://www.Selsam.com

*****Synopsis******
So I'm wondering what other machines others are bringing, what kitees, balloons, etc., and what might be capable of lifting the upper end of a Superturbine(R) if I can manage to get one up there?

I'll stop now while there is still daylight left and this is not too long to read.
*******************************************************88
Sincerely
Doug Selsam
digressing into just a few more minutes of "the all-talk-format"
(it's always "just a few more minutes")
It is very hard to actually get anything done. That is my point. And with all these patents all around the world and such promising solutions, I could use some help. Superturbine(R) IS the solution the world purports to be looking for.
Superturbine is a registered U.S. Trademark.