Messages in AirborneWindEnergy group.                       AWES3389to3439 Page 48 of 79.

Group: AirborneWindEnergy Message: 3389 From: dave santos Date: 4/16/2011
Subject: Re: Sense & Avoid Radar Function (Open Source Standard)

Group: AirborneWindEnergy Message: 3390 From: Robert Copcutt Date: 4/16/2011
Subject: Re: Open Source AWE Automation?

Group: AirborneWindEnergy Message: 3391 From: Dave Lang Date: 4/16/2011
Subject: Re: Open Source AWE Automation?

Group: AirborneWindEnergy Message: 3392 From: Grant Calverley Date: 4/16/2011
Subject: Re: Open Source AWE Automation?

Group: AirborneWindEnergy Message: 3393 From: Joe Faust Date: 4/16/2011
Subject: Re: Open Source AWE Automation?

Group: AirborneWindEnergy Message: 3394 From: Uwe Fechner Date: 4/16/2011
Subject: Re: Open Source AWE Automation?

Group: AirborneWindEnergy Message: 3395 From: dave santos Date: 4/16/2011
Subject: Two Great "Smart Winch" Primers

Group: AirborneWindEnergy Message: 3396 From: harry valentine Date: 4/16/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")

Group: AirborneWindEnergy Message: 3397 From: Joe Faust Date: 4/16/2011
Subject: Re: Two Great "Smart Winch" Primers

Group: AirborneWindEnergy Message: 3398 From: Carlo Perassi Date: 4/17/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")

Group: AirborneWindEnergy Message: 3399 From: dave santos Date: 4/17/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")

Group: AirborneWindEnergy Message: 3400 From: dave santos Date: 4/17/2011
Subject: Ampyx Power Plane Video

Group: AirborneWindEnergy Message: 3401 From: dave santos Date: 4/17/2011
Subject: Joby downsizes its concept; Makani adds more motors & tail-booms...

Group: AirborneWindEnergy Message: 3402 From: dave santos Date: 4/17/2011
Subject: ATCRBS Radar Environment for AWE (TACO Addendum)

Group: AirborneWindEnergy Message: 3403 From: Joe Faust Date: 4/17/2011
Subject: Re: ATCRBS Radar Environment for AWE (TACO Addendum)

Group: AirborneWindEnergy Message: 3404 From: DavidC Date: 4/18/2011
Subject: Onboard data logging

Group: AirborneWindEnergy Message: 3405 From: mmarchitti Date: 4/18/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")

Group: AirborneWindEnergy Message: 3406 From: Bob Stuart Date: 4/18/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")

Group: AirborneWindEnergy Message: 3407 From: dave santos Date: 4/18/2011
Subject: Re: Onboard data logging

Group: AirborneWindEnergy Message: 3408 From: DavidC Date: 4/19/2011
Subject: Re: Onboard data logging

Group: AirborneWindEnergy Message: 3409 From: dave santos Date: 4/19/2011
Subject: Re: Onboard data logging

Group: AirborneWindEnergy Message: 3410 From: dave santos Date: 4/19/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")

Group: AirborneWindEnergy Message: 3411 From: Theo Schmidt Date: 4/20/2011
Subject: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE Auto

Group: AirborneWindEnergy Message: 3412 From: Pierre Benhaiem Date: 4/20/2011
Subject: FlygenKite at "Concours Lépine International Paris"

Group: AirborneWindEnergy Message: 3413 From: Pierre BENHAIEM Date: 4/20/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE

Group: AirborneWindEnergy Message: 3414 From: Joe Faust Date: 4/20/2011
Subject: TR Tether Rotations

Group: AirborneWindEnergy Message: 3415 From: Robert Copcutt Date: 4/20/2011
Subject: Re: Sense & Avoid Radar Function (Open Source Standard)

Group: AirborneWindEnergy Message: 3416 From: dave santos Date: 4/20/2011
Subject: 10USD COTS AWECS

Group: AirborneWindEnergy Message: 3417 From: dave santos Date: 4/20/2011
Subject: Open Source Collaboration

Group: AirborneWindEnergy Message: 3418 From: Grant Calverley Date: 4/20/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE

Group: AirborneWindEnergy Message: 3419 From: dave santos Date: 4/20/2011
Subject: Single v. MultiLine AWECS

Group: AirborneWindEnergy Message: 3420 From: dave santos Date: 4/20/2011
Subject: Survey of US Midwestern AWE Research (Pt. 1, Nebraska- "Furry" of th

Group: AirborneWindEnergy Message: 3421 From: Bob Stuart Date: 4/20/2011
Subject: Re: Survey of US Midwestern AWE Research (Pt. 1, Nebraska- "Furry" o

Group: AirborneWindEnergy Message: 3422 From: dave santos Date: 4/20/2011
Subject: Survey: Midwestern AWE Research (Pt 2, Texas High Alitude Kite Test

Group: AirborneWindEnergy Message: 3423 From: Pierre BENHAIEM Date: 4/21/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE

Group: AirborneWindEnergy Message: 3425 From: Pierre Benhaiem Date: 4/21/2011
Subject: AWE to take the place of conventional wind turbines

Group: AirborneWindEnergy Message: 3426 From: maccleery Date: 4/21/2011
Subject: Re: Airborne Wind Media Coverage

Group: AirborneWindEnergy Message: 3427 From: Grant Calverley Date: 4/21/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE

Group: AirborneWindEnergy Message: 3428 From: Grant Calverley Date: 4/21/2011
Subject: Re: Single v. MultiLine AWECS

Group: AirborneWindEnergy Message: 3429 From: dave santos Date: 4/21/2011
Subject: Re: Single v. MultiLine AWECS (gigawatt strategy)

Group: AirborneWindEnergy Message: 3430 From: Pierre BENHAIEM Date: 4/22/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE

Group: AirborneWindEnergy Message: 3431 From: dave santos Date: 4/22/2011
Subject: Realistic Tether Dynamics

Group: AirborneWindEnergy Message: 3432 From: Grant Calverley Date: 4/22/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE

Group: AirborneWindEnergy Message: 3433 From: Joe Faust Date: 4/22/2011
Subject: Lateral veering (LV)

Group: AirborneWindEnergy Message: 3434 From: Dave Lang Date: 4/22/2011
Subject: Re: Realistic Tether Dynamics

Group: AirborneWindEnergy Message: 3435 From: dave santos Date: 4/22/2011
Subject: Re: Realistic Tether Dynamics

Group: AirborneWindEnergy Message: 3436 From: dave santos Date: 4/22/2011
Subject: Re: Airborne Wind Media Coverage

Group: AirborneWindEnergy Message: 3437 From: Bob Stuart Date: 4/22/2011
Subject: Re: Single v. MultiLine AWECS

Group: AirborneWindEnergy Message: 3438 From: Joe Faust Date: 4/22/2011
Subject: Re: Lateral veering (LV)

Group: AirborneWindEnergy Message: 3439 From: dave santos Date: 4/22/2011
Subject: Re: Single v. MultiLine AWECS




Group: AirborneWindEnergy Message: 3389 From: dave santos Date: 4/16/2011
Subject: Re: Sense & Avoid Radar Function (Open Source Standard)
Robert,
 
"Professional pessimism" was meant in the special sense of, say, a cautious sea captain pondering a bold course, or like Daedalus & Icarus.
 
Its true that kite-killing will become less frequent at larger scales (large arrays), but the back-up need may remain.
 
No one else is doing it, so you should seriously undertake to draft the central plan you describe, it would be welcomed,
 
daveS
 
 
 
Group: AirborneWindEnergy Message: 3390 From: Robert Copcutt Date: 4/16/2011
Subject: Re: Open Source AWE Automation?
Doug,

Your warning is heard but I have not seen your alternative suggestion in
enough detail to be convinced that it should be pushed as a global
standard.

Cranes, lifts (elevators) and fishing boats use winches. They do wear
but a well made system should last long enough to be economical. At
least with AWE there is no need to get to the top of a tall tower to do
that servicing.

Again, fabric is still used in many applications. Covering the blades of
turbines on a tower may not be the best plan because of difficulty of
access. The system I am thinking of does not have these access problems
because the airborne wing will be easily docked for repair as soon as a
problem develops.

Turbines all need a system for turning out of the wind when it gets too
strong. They still rarely achieve a capacity factor better than 25%. AWE
could do a bit better than this by having different sized wings for
different conditions. That eases the durability requirement of the
fabric. It also means the wings need to be cheap and using fabric should
help with this too.

Robert.


Group: AirborneWindEnergy Message: 3391 From: Dave Lang Date: 4/16/2011
Subject: Re: Open Source AWE Automation?
FWIW, regardless of what Doug may claim about winch-reliability,
the folks at Markey Winch in Seattle (I think they have about 60% of the world marine winch manufacturing trade), quote MTBF's of 40 YEARS!

DaveL




At 10:16 AM -0700 4/16/11, dave santos wrote:
Group: AirborneWindEnergy Message: 3392 From: Grant Calverley Date: 4/16/2011
Subject: Re: Open Source AWE Automation?
Markey Winch in Seattle also make a smart winch for tugs that dock monster LPG tankers. The dynamic wavy offshore conditions  would snap lines on dumb winches.  We saw it demonstrated.  It generates up to 1 MW of power that gets dumped into electric heat on the outbound stroke and is a regular winch on the inbound. You can have one for 800 grand and they last 40 years.
 

Grant Calverley
360-378-6186



Group: AirborneWindEnergy Message: 3393 From: Joe Faust Date: 4/16/2011
Subject: Re: Open Source AWE Automation?
Group: AirborneWindEnergy Message: 3394 From: Uwe Fechner Date: 4/16/2011
Subject: Re: Open Source AWE Automation?
Hi,

as some of you will know, we are implementing an automated kite power system at TU Delft.
This is not an easy task. I support the idea of open source kite power automation. Some
ideas:
- as communication protocol for the inter-operation of equipment of different groups
  I suggest to use the CAN aerospace protocol:
  ( http://www.stockflightsystems.com/index.php?option=com_content&task=view&id=13&Itemid=53 )
  Advantages:
  - cheap
  - reliable
  - freely available standard
  - quite easy to implement
- we use the following software components:
  - Linux
  - Xenomai (to make Linux hard real-time capable)
  - RTNet for real-time communication between the computers on the ground
  - Orocos as middle-ware, to implement distributed, real-time, agent-based control systems
  - C++
  - MISRA C++ coding standard for secure C++ software

I think, that the high security requirements of aviation are not needed for kite based HAWP systems,
because kites are very safe, as long as you are able to cut the main power cable in case of a control
system failure.

This are all the ideas, I currently want to share with you.

Hope to see you in Leuven.

Regards:

Uwe Fechner, TU Delft

Group: AirborneWindEnergy Message: 3395 From: dave santos Date: 4/16/2011
Subject: Two Great "Smart Winch" Primers
Sorry Doug, it seems winches are quite viable as an ECS, as the oceanographic state-of-the-art shows, with high reliability (winches lasting longer than the ship itself) & fairly high efficiencies (
 
Oceanographic winches meet very similar dynamic demands to what AWE requires. DaveL mentioned Markey Winches, but who knew old Markey, P.E., was such a prose artist (Join the "Waterfront Tribe")? Note that ocean winches are shown to generate considerable power during pay-out-
A competing firm, InterOcean, is also very impressive-
 
 
 
 
 
Group: AirborneWindEnergy Message: 3396 From: harry valentine Date: 4/16/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")
Good to hear of Kitegen's progress. Perhaps a future scaled-up version of the carousel will involve a circular railway track, providing guidance in the horizontal direction and vertical restraint. It would be interesting to see if they could combine kites at 10,000-ft in the power generation phase of the cycle with other kites at 1000-ft in the relaxed phase of the cycle. Big diameter of the circular track will reduce the risk of lines crossing each other.
 
 
KiteGen's concept definately has potential
 
 
Harry

 

To: airbornewindenergy@yahoogroups.com
From: santos137@yahoo.com
Date: Sat, 16 Apr 2011 09:01:31 -0700
Subject: [AWECS] KiteGen Completing 3mw Pilot Plant ("video interessanti")

 
 
KiteGen has for years led the AWE field in demonstrating significant power generation from kites, with 40kw the standing record since 2006. Now they are poised to activate a 3mw (estimated) pilot plant, the first utility scale operation ever. Their sercet seems to be a lucky combination of great timing, practical visionaries, cooperative R&D, & old fashioned fundraising.
 
One can predict they will produce lots of power, but also experience all sorts of (valuable) hard lessons. They do not intend to stay at this scale, its just a stepping stone to the gigawatt-scale they are focused on (carousel concept). The video link below is an interview with Massimo, with many shots of the large construction being completed-
 
http://www.hybrid-synergy.eu/showthread.php?tid=20873

Machine translation of the text below-
 
Recent Interview of Ippolito & system images-
 
Saying goes that in this last year c' it has been un' acceleration dell' visible activity. To July dell' past year I have accompanied of the persons on the knoll of Berzano, where c' it was only a part of the external structure. Little weeks after the intense activities have moved to Sommariva Hinge, and here l' activity has gone ahead in phrenetic way: winches, motoalternatori, slitte, canes, pulegge, groups buffer of power have been assembled the mechanical subcomponenti () many already have been installed all' inside of the structure as it can be seen from the video, and already has been carried out some maneuvers. We keep in mind who the first flight can be little meaningful, with the exception of the first flight of an aircraft. Speaking with some I have had l' impression that us has been a misunderstanding on supposed delays of the plan. Probably it will have been spoken about un' installation of the Gen Piece of furniture, thus com' it was, under the structure, for tests on the software: un' relatively simple and fast operation. Someone will even have intentional to understand instead that in a short time l' system would have worked. Insomma, also to good sense it can be understood that it is not come true un' system of the sort, of this complexity and innovation, in little months, as someone expected.
 
 
----- Forwarded Message -----
From: mmarchitti <marchitti@hotmail.com
  
Recente iintervista a Ippolito e immagini dell'impianto
 
http://www.hybrid-synergy.eu/showthread.php?tid=20873

Va detto che in questo ultimo anno c'è stata un'accelerazione dell'attività visibile. A Luglio dell'anno scorso ho accompagnato delle persone sulla collinetta di Berzano, dove c'era solo una parte della struttura esterna. POche settimane dopo i lavori si sono spostati a Sommariva Perno, e qui l'attività è andata avanti in modo frenetico: sono stati assemblati i subcomponenti meccanici (argani, motoalternatori, slitte, canne, pulegge, gruppi buffer di potenza) molti sono già stati installati all'interno della struttura come si può vedere dal video, e sono già state effettuate alcune manovre. Teniamo presente che il primo volo può essere poco significativo, a differenza del primo volo di un velivolo. Parlando con alcuni ho avuto l'impressione che ci sia stato un equivoco su supposti ritardi del progetto. Probabilmente si sarà parlato di un'installazione del Mobile Gen, così com'era, sotto la struttura, per prove sul software: un'operazione relativamente semplice e veloce. Magari qualcuno avrà voluto capire che invece in poco tempo l'impianto avrebbe funzionato. Insomma, anche a buon senso si può capire che non si realizza un'impianto del genere, di questa complessità e innovazione, in pochi mesi, come si aspettava qualcuno.




Group: AirborneWindEnergy Message: 3397 From: Joe Faust Date: 4/16/2011
Subject: Re: Two Great "Smart Winch" Primers
Group: AirborneWindEnergy Message: 3398 From: Carlo Perassi Date: 4/17/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")
On Sat, Apr 16, 2011 at 6:01 PM, dave santos <santos137@yahoo.com Dave, according to what Dr. Marchitti (the board member of Kite Gen
Research Srl you cited) stated during a meeting last Friday - and
using the well known Beatles song as a pun - the path for that machine
to reach and hold for some period a power of 3 MW is still a long and
winding road. Don't expect that it reaches such a goal in a few
months... it's a long run target, though he didn't say how long it
would be.

--
Carlo Perassi - http://perassi.org/
Group: AirborneWindEnergy Message: 3399 From: dave santos Date: 4/17/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")
Carlo,
 
Yes, its quite clear that KiteGen must work up to the calculated 3MW, starting with smaller kites in modest winds, but the large scale of the turret house looks like its built to go all the way. Its also predictable that there will be a lot of redesign of some components.
 
My particular concern is about the kite. An LEI C-kite will spin wildly with considerable drag if pulled in fast by one line & even a flat parafoil would not be too stable. Twisted lines will generally result in a session failure. It seems that a special new kind of kite is needed to fly the retract reliably. The solution may be as simple as swivels on each line at the kite, or as complex as active-control sideways flight during retract.
 
The stem also looks prone to whiplashing under short-lined launching conditions & may require strong damping.
 
But overall WOW/KiteGen is a clear leader in the AWE field & just needs to persevere,
 
daveS 

From: Carlo Perassi <carlo@perassi.org
 


Group: AirborneWindEnergy Message: 3400 From: dave santos Date: 4/17/2011
Subject: Ampyx Power Plane Video
Ampyx has cast its lot with with AWEC's (AWE Consortium) deceptive pay-to-play promotional model & was therefore (marginally) included in the Popular Mechanics cover feature last month, which otherwise studiously omitted consideration of EU teams & many promising low-complexity AWE players.
 
The latest video from Ampyx contains a brief sequence of actual flight mixed with animations, but the toughest part, the spinning launch & landing arm, is not shown working in the real world. They also seem to be claiming scalability without sprawl by mature collision avoidance of multiple kiteplanes set within each other's tether scopes.
 
 
 
Group: AirborneWindEnergy Message: 3401 From: dave santos Date: 4/17/2011
Subject: Joby downsizes its concept; Makani adds more motors & tail-booms...
As pathetic as the March Popular Mechanics article was as a balanced picture of AWE R&D, it did contain hints to the problems the "leaders" are having. 
 
When Joby Energy first announced its intention to develop a jumbo-scale electric autonomous high-duty aircraft capable of VTOL & aerobatic operation, the no-brainer KiteLab prediction was that they could not possibly succeed, given severe scaling penalties, inadequate capitalization, & limited aerospace culture. So its no surprise that Joby has downscaled its target design from a 240ft WS to a 200ft WS, for a nearly 50% reduction in scaling penalty. We previously saw Makani Power's kitesurfer management go through the same process of quietly backing off of 10,000m altitude targets for their flygen kiteplanes, only to end up well under 1000m, for multiple critical reasons. Makanis current scale is around 90ft WS. Somewhere along the line they learned that flying wings are not yaw-stable enough & now they have likely overreacted by adding three tail-booms to the M-1 concept. Three more motor/generators have also been added, for six total, but its still unlikely to perform robust VTOL.
 
The revised KiteLab prediction is that Joby will be forced to continue to downsize drastically & even a "retooled" Makani must continue to reduce its ambitions. Its also probable that given continued poor performance of overrated flygens, the groundgen companies will finally begin to attract major quality investment & take-off spectacularly, while the once hot flygen comapanies languish in the famous VC "valley-of-death", bleakly awaiting maturation of premature dreams.
 
 
 
 
Group: AirborneWindEnergy Message: 3402 From: dave santos Date: 4/17/2011
Subject: ATCRBS Radar Environment for AWE (TACO Addendum)
The US Congress has approved funding to replace the existing Air Traffic Control Radar Beacon System (ATCRBS) with a GPS enabled system as part of NextGen starting about 2014. The transition will be slow & both types of technology will coexist for a long period. Radar is still rapidly improving as a tool (Mode S) even as questions about GPS over-reliance persist. 
 
Standard ATCRBS is capable of providing the data required for managing large AWECS arrays in shared airspace, but the AWE Utility needs to operate its own system or somehow get its data in realtime from governmantal ATC. The critical AWE data needed is how well elements keep station or fly patterns, plus detecting intrusions from outside for "sense & avoid". Radar transponders are a major feature, but not really needed operationally by an AWECS, as each element is constrained by tether(s) in its known airspace. Airspace management may not need an AWECS transponder squawk since a kite farm is more like a persistent obstruction marked on the airspace.
 
GPS will eventually provide far more functionality with adequate security, but it may be the riskier R&D play if competing with secondhand or futher optimized ATCRBS systems of higher security. A KIS advantage is not to fly any more avionics that absolutely necessary, for reasons of O&M, weight, power, etc. An AWECS radar system can be almost entirely ground-based.
 
 
 
 
Group: AirborneWindEnergy Message: 3403 From: Joe Faust Date: 4/17/2011
Subject: Re: ATCRBS Radar Environment for AWE (TACO Addendum)
Group: AirborneWindEnergy Message: 3404 From: DavidC Date: 4/18/2011
Subject: Onboard data logging
In the search for onboard airspeed measurement and data logging, I ran across this site:

http://www.eagletreesystems.com/standalone/standalone.htm

At these prices, maybe I'll buy two.

DavidC
Group: AirborneWindEnergy Message: 3405 From: mmarchitti Date: 4/18/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")
Sure Dave, there is a lot of work to do, a lot of research and effort to complete the plant. Nevertheless we have to be content about the job already done, that in the last period has been noticeable even to the absent minded eye. There are people (not so many, as this project actually would deserve) that are very committed to its success, that are working a lot and very hard, with very little money reward.

Actually it is difficult to settle a road map or a precise timetable of the activities, for several reasons: many technical aspects are at the border of the research, as Dave has pointed out, and are in some ways unpredictable: the wing, the cables, the sensors, the data transmission, the safety, the motor/generator drivers, the energy buffer, the control software - just to name a few. (We have to remember that important aircraft project (Boeing 787, Airbus A380, A400) has suffered several years delay). Moreover, the KiteGen project is not supported by safe and substantial funds, therefore it is difficult to offer contracts for technicians, therefore tasks that could proceed in parallel have to proceed in series. But there are also social difficulties, with the authorities, with people organizing fund raising, etc. Unfortunately KiteGen program has been very very little supported by the government fund; and private support is not easy to manage/arrange. Therefore we have to look at KiteGen with a benevolent eye on these aspects. Actually, for KiteGen project, my commitment has been mainly devoted to this last aspect, as a WOW founder (at that time with the biggest share with another founder) and WOW board member.

I think that in the last decades society has lost cohesion, it has lost the spirit that in the previous century allowed the achievement of important scientific-technological goals. For example Einstein letter to Roosevelt was followed by the Manhattan project to exploit the nuclear energy - even though for war purpose. I am always moved when I look at this video at time 14'28", http://www.youtube.com/watch?v=XrhDaAmn5Uw , when JFK announces the space program: "we were all in it together".

Group: AirborneWindEnergy Message: 3406 From: Bob Stuart Date: 4/18/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")

On 18-Apr-11, at 1:52 PM, mmarchitti wrote:


I once spent a weekend trying to understand a research grant application.  Finally, I realized that it could be summarized as follows:
1  What will you discover?
2  How much will it cost to find it?
3  Sign here to swear you don't already know.

Business is uncomfortable with uncertainty, so it permits lying.
Bob Stuart
Group: AirborneWindEnergy Message: 3407 From: dave santos Date: 4/18/2011
Subject: Re: Onboard data logging
DavidC
 
You may want to hold out for more functionality; the 2010 Brunion Unit below is discounted to the same price (37USD) & does far more than record one peak data point on a single digit display. You can also get an IR/USB data port to log from, say, a cell phone.
 

Pro: Brunton - Lanterns, Solar Power, Headlamps, Binoculars ...

The most comprehensive data center available to backcountry explorers and outdoor professionals. Measures, counts, tracks, interprets, forecasts and logs virtually every aspect of your trip. Because knowledge is power. ...
store.bruntonoutdoor.com/instruments/altimeters-wind/pro/ - Cached-
 
 
There are endless new wirstwatch altimeter windspeed combos, look for those that are discounted, log, & have data ports-
 
High altitude kiters use two watches & witnesses for record attempts.
 
Wayne German likes the Android OS platforms, but every flashy feature can be nicely done by cruder means, any full featured dataphone can do essential intrumentation, with a few external sensors. I like to point a videocam at an experiment with small readable instruments in the frame; advanced videogrammetry.
 
Another option is the great varios used in soaring sports, which with kites would  report tether angle gust response. 

Paragliding Variometer - Paraglider Varios, Altimeters and GPS ...

Back in 2007 i used Hobo data loggers KiteShip gave me, with the light level sensor as an optical channel for my DIY sensors.
 
With a kite you can always just do as the ancient Chinese general & measure theodolytic angle from the ground for altitude. One easily finds altitude by line length & flight angle, with a correction for line sag, who needs more? Windspeed  is also measured  by simple means, if one is not too proud. Hotwire anemometers are an easy school-kid project, but you have to calibrate them on a moving vehicle.
 
Back in 2007 this was THE hot tiny autopilot, but its pricey. Reed Chistiansen is gifted designer, even if his product is used for dubious defense apps.

Procerus Technologies : Kestrel Autopilot 

At 16.65 grams, the KestrelAutopilot is the smallest and lightest full- featured autopilot on the market
Careful with spending, money runs out fast with avoidable purchases & UHMWPE is the biggest outlay,
 
daveS 
 
 

 
Group: AirborneWindEnergy Message: 3408 From: DavidC Date: 4/19/2011
Subject: Re: Onboard data logging
Wow. This certainly is a wealth of data, Dave. Thanks.

We have found that most anemometers are not designed for high parafoil wind velocities. In addition, we have had to recalibrate several off-shelf units with our in-house wind tunnel and pitot tube setup. The great thing about a pitot tube is that they are easy to fab, and you can look directly at the manometer fluid without having to trust someone else's electronics.

Being a Chinese general has a certain appeal. We will certainly employ redundant data checking, and the old trig approach has real appeal in this regard. Getting the angular rate info will be more challenging, though I could rig a couple of pots after I master the basics of flight.

What is your concern about UHMWPE? Is there some particular component of concern? I use PE and UHMWPE for many of my high voltage assemblies, but it doesn't rank much above other material in modest prototype quantities.

DavidC

Group: AirborneWindEnergy Message: 3409 From: dave santos Date: 4/19/2011
Subject: Re: Onboard data logging
DavidC,
 
Angular rate data is part of a good videgrammetric record. Its probable that at high airspeed the flow in the tiny pitot on the Eagle unit acts nolinearly, even acting like a whistle at off angles, but such issues just distract from core inventive solving of AWE. A hot wire anemometer is even easier to fab, one just breaks a small light bulb open. Avionics used in hang gliding & ultralight aviation have the right airspeed range for fast parafoils. The point about UHMWPE tethers is that of all the fancy things one can spend AWE R&D money on, likely no other single item is so worthwile to blow some money on, from a reliability cost-benefit view. Small AWE players who would outperform the lavishly funded teams must do so with superior ideas, not purchasing power.
 
I forgot to mention how the tremendous depth-of-field of a tiny phone cam lense is what enables arrays of tiny instruments to display right at the camera (like a meteo watch face), with distant objects also in focus. Its also practical to set up little "rear view mirrors" to monitor proximity events outside the FOV. Video is the dominant logging multi-sensor of our time,
 
dave
 
 

From: DavidC <david@carmein.com
 
Wow. This certainly is a wealth of data, Dave. Thanks.

We have found that most anemometers are not designed for high parafoil wind velocities. In addition, we have had to recalibrate several off-shelf units with our in-house wind tunnel and pitot tube setup. The great thing about a pitot tube is that they are easy to fab, and you can look directly at the manometer fluid without having to trust someone else's electronics.

Being a Chinese general has a certain appeal. We will certainly employ redundant data checking, and the old trig approach has real appeal in this regard. Getting the angular rate info will be more challenging, though I could rig a couple of pots after I master the basics of flight.

What is your concern about UHMWPE? Is there some particular component of concern? I use PE and UHMWPE for many of my high voltage assemblies, but it doesn't rank much above other material in modest prototype quantities.

DavidC



Group: AirborneWindEnergy Message: 3410 From: dave santos Date: 4/19/2011
Subject: Re: KiteGen Completing 3mw Pilot Plant ("video interessanti")
Mario,
 
A nice strategic option for KiteGen is to host experiments of several leading kite variations, from autogyros & varidrogues to kite trains & turbine blimps, to recoup capital costs & directly compare practices. If the path is hard for KiteGen, due to authorities & impatient stakeholders, at least you can say- "Non dubitate Colombo, il Nuovo Mondo è reale."
 
You noted- "I think that in the last decades society has lost cohesion, it has lost the spirit that in the previous century allowed the achievement of important scientific-technological goals."
It is alarming how fast the old is dissolving right before our eyes, but maybe the world is like a chrysallis, wherein the larva must first dissolve to reorder as a butterfly-
 
Now, if Doug can explain how the delicate kite-like inflated membrane wings of a Monarch Butterly endure such heroic migrations....
 
daveS
Group: AirborneWindEnergy Message: 3411 From: Theo Schmidt Date: 4/20/2011
Subject: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE Auto
Doug schrieb:
...
...

Wind turbine sailboats use the rotor *either* unbraked in the autogyro mode as a
sail, *or* as a turbine connected to a load. I'm wondering if this would be any
different with AWE. I.e. a rotor would be *either* a kite *or* a turbine.
Presumably a rotor could do both at the same time, but would it be better to use
multiple rotors?

Theo Schmidt
Group: AirborneWindEnergy Message: 3412 From: Pierre Benhaiem Date: 4/20/2011
Subject: FlygenKite at "Concours Lépine International Paris"

I shall present FlygenKite and AWE (perhaps for the first time for this manifestation) at the "Concours Lépine International Paris", Pavillon 7.3/Foire de Paris,Parc des Expositions,Paris, France,  

2011 April 28-May 8.

Shedules:from 10 a.m. to 7 p.m.,excepted April 29 and May 3-5:from 10 a.m. to 9 p.m.;and May 6 :from 10 a.m. to 11.p.m. .

Number of my stand:II 7.I shall be on my stand April 28-May 2 and May 6-8.

And also I wish a good conference AWE in Leuven (I cannot be present).

PierreB

http://flygenkite.com

Group: AirborneWindEnergy Message: 3413 From: Pierre BENHAIEM Date: 4/20/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE
It seems that SkyMill Energy, Inc. shows a reel-out scheme where the autogyro is towing the drum working the ground generator,that like a kite (in reel-out scheme).Rotokite Sequoia | Patents and Rotokite could be defined as a sort of autogyro being a set of two opposite soft kites.In contrast the autogyro in Sky wind power (flygen,not reel-out) works both as kite and turbine.

PierreB

http://flygenkite.com


Group: AirborneWindEnergy Message: 3414 From: Joe Faust Date: 4/20/2011
Subject: TR Tether Rotations

KITE SYSTEMS' TETHER ROTATIONS
(kite is an object having a wing set, tether set, and resistive-system set, and media set)

1. Around the mooring as a radial arm. (booms, stems, linear push-pull).
This may be incidental or a matter of high focus for energy production or performance of special tasks or both.

2. Around its own longitudinal axis. (twist, torque, adjusting from twist, adjusting  from tension).
This may be incidental or a matter of high focus for energy production or performance of special tasks or both.

3. Reel-in-reel-out cycling. 
This may be incidental or a matter of high focus for energy production or performance of special tasks or both.

4. Around tether terminal pulleys in the loop or fan-belt mode.
This may be incidental or a matter of high focus for energy production or performance of special tasks or both.

5. Session on-and-off cycling.
This may be incidental or a matter of high focus for energy production or performance of special tasks or both.

6. Cross-sectional size cycling (from temperature changes, from tension changes)
This may be incidental or a matter of high focus for energy production or performance of special tasks or both.

7. Electrical-charge condition of tether set cycling.
This may be incidental or a matter of high focus for energy production or performance of special tasks or both.

8. Maintenance change-out cycling.
This may be incidental or a matter of high focus for energy production or performance of special tasks or both.

9. Vogue cycling. Tether type and use will come in and out of focus or use. Some choices and combinations will cycle in and out of focus or use for various reasons; good design for target purpose may or may not drive actuation; art or open play might drive the choosing; exploration might bring in a cycle of use of a partcular tether combination. 

10. Tethers may cycle lengths by stretch-shrink actuated by say mechanical force, light, electrical reaction, moisture reacting, chemical triggering, etc. Cycling of the length of tether elements may have niche applications.

11. Color or illumination cycling for tether elements may be actuated in various ways to serve various purposes (communications, hazard warning, art, condition reporting, etc. )

12. Tether elements may rotate wholly or segmentally about centers of wave action in planes or in full 3-space. (standing wave nodes, anti-nodes, harmonics, etc.; longitudinal waves, etc. The frequencies and cycles about numerical quantities form another branch of cycling or rotation for tethers.)

13. Tethers (wholly or in part) may rotate in and out of a media ( e.g., in and out of water, in and out of air) during an operation session

Types of tether rotations may occur singly or in combination with other rotations.

The count of combinations and niche applications of these rotations is substantial with subsequent opportunities for designers and products. Some arrangements will be more popular than others. Profit in the production and selling of energy from an AWECS or kite-energy system may be maximized in part by a certain use of tether rotations.

Missed tether rotations are invited to be described.
 
Examples and niche applications of each type of tether rotation (or combination of rotations) are invited.

Presentation of practical products employing one or more or combination of tether rotation are invited to be described and discussed.

Well describing the rotations in a particular specification is invited for the record, even if some of the description is absent from sales literature.

Neglect of knowing and respecting  the rotations occurring in a tether could possibly be part of a failure mode. Attention over tether rotations may play in a success story.

Happy tether rotating ...
JoeF

Group: AirborneWindEnergy Message: 3415 From: Robert Copcutt Date: 4/20/2011
Subject: Re: Sense & Avoid Radar Function (Open Source Standard)
Dave S,

Oh well, I walked straight into that one! I am happy to start off with a
document that explains my thinking but in the spirit of open source I
think it should become a collaborative effort.

Robert.


Group: AirborneWindEnergy Message: 3416 From: dave santos Date: 4/20/2011
Subject: 10USD COTS AWECS
 Last night a mysterious red light appeared high in the Texas sky. It was the latest AWE science toy, assembled & flown by a kid. The wind generator used was a popular science kit selling for under 8USD & the pilot-lifter kite was a 3USD toy delta. Total assembly took about 20 minutes & the kite then easily lifted the generator in about an 8kt breeze, flying at a ~45 degree angle. It would have taken a bit more wind to lift an added conductive cable, but thats the obvious next step. If nothing else. this is clearly an effective milliwatt AWECS for educational purposes.
 
Green Science Windmill Generator by Toysmith 4151
 
This is the exact model kite, but any comparable wing will do.
 
Ages 8 & up. Learn about renewable energy with this wind generator. LED light will glow as it is powered by free energy from the wind. No ...
Compare
Group: AirborneWindEnergy Message: 3417 From: dave santos Date: 4/20/2011
Subject: Open Source Collaboration
Robert,
 
Its lately become clear that the open source AWE movement is the biggest & most dynamic player, so your initiative is timely. Count on wide group support of your effort to draft a common open-source AWE R&D plan. A suggestion is to fully integrate academia & base core findings on direct comparative testing by multiple independent parties.
 
Good luck with an important task,
 
daveS
 
 

 
Group: AirborneWindEnergy Message: 3418 From: Grant Calverley Date: 4/20/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE
Hi Theo and Pierre,
Autogyros or Gyrogliders, wind turbines and helicopters are all related but are quite different.  With a wind turbine the blade angle of attack (AOA) tends to be negative (below 0 degrees). This negative angle directs the lifting force of the airfoil more into torque. With a helicopter the AOA is positive (above 6 or 8 degrees) Most of the force is directed to lift but of course needs to be powered around with a motor. An Gyroglider is the exact middle with a AOA from 2 to around 6 degrees.  The middle third of the rotor acts like a wind turbine and add torque and rotation to the system. The outer 1/3 of the disc act like a helicopter and adds lift.  The torque and the lift magically balance each other. The variable is the rotors RPM which goes up and down with the wind speed or the amount of wind collected.  (the rotor discs AOA or how much it is tipped into the wind)
 
The problem as I see it, is a airfoils lift goes up or down as a function of the square of the wind speed. (actually cubed in theory).(this is true up to the point of the airfoils drag rise as it gets close to Mach 1, but that is another issue unique to rotors).  With concepts like Skywind power or Doug S. Super Turbine (TM) they are taking torque out of the autogyro rotor. Doing that they are slowing the rotor down and loosing lift by the square.  This is like stealing the goose the laid the golden egg and adds an complex control balancing act.  How much lift can you steal by tapping the torque of an gyroglider rotor before you fall out of the sky?. (the answer is not very much, if you ask a aurogyro pilot who has touched the rotor break in flight, not a recommended maneuver. Freeflight and tethered flight are quite different so it is not a perfect example.) One could say reeling out by 1/3 windspeed does the same thing with the ground gen, cross wind maneuvering helps bring some of the lift back.  (However, there is a big limiter to cross wind power and that is tether drag, which also goes up by the square (cube?) as the speed increases.  Having 2 to 4 tethers really adds killer drag. To fly fast, say 200mph like Makani or Ampex you need a short single tether under 1000 meters or the tether drag will be overwhelming. (I don't buy that they are only flying low because of the FAA)  At jet steam altitudes gentle shunting crosswind maneuvers can help with gyrogliders up to a point where they begin be a detriment due to the drag caused by the long fast moving tether.
 
Letting the rotor free spin and find its natural RPM there is no concern about over speeding the generators so that control problem is not an issue. Also changing from wind turbine to helicopter and back as Joby, Skywindpower and Makani are proposing can be done but is very complicated with helicopter style swash plates, motor/generators and such.  If they are to work for months at a time without maintenance this mechanical complexity is an issue. The pure Gyroglider uses a bearing and some simple hinges in the hub making in mechanically robust concept working in almost pure tension.
 
Concepts like the rotokite, Jobys latest auto rotation style patent, and other twin kites will work well at low line angles, low in the sky. From 0 to 45 degrees. Basically they are just working like a big tethered downwind wind turbines.  The same could be said for Makanis circle looping kites.  To go above 45 degrees they kind of need that middle third of a rotor adding torque into the system so it can drive the outer third back into the wind.  Also the hub (not just a tether connection between kites) is an  important component.  There is desymmetry of lift in a rotor.  The hub helps transfer torque generated on one side to the other keeping the system in balance. This I have learned this is critical especially at the start up.
 
If you are satisfied with working 500 to 1000 meters with tether angles low to the ground (under 45 degrees) most of these concepts will work fine.   To go higher to the jetstream levels you need to get your single tether above 45 degrees or your line length gets crazy long and adds too much drag. We have found the gyroglider rotor with a ground gen is one way you can do that.
 
The biggest question in the end is ROI.  If your ROI is 2x what a HAWT is, is there enough profit for the risk the investor takes or would the prudent investor just invest in twice as many HAWT and accept a lower more stable return.  With the SkyMill Gyroglider we are seeing a preliminary 4x improvement in ROI over HAWT in select locations. We find this very encouraging.
 

Grant Calverley
360-378-6186



Group: AirborneWindEnergy Message: 3419 From: dave santos Date: 4/20/2011
Subject: Single v. MultiLine AWECS
Grant,
 
Thanks for a very insightful description of autogyro-based AWE. An old issue raised was the single v. multi-line debate, hence this thread reviewing new findings. Old objections to multilines were generally true, that there is a drag penalty & handling issues, but the counter case is ever more compelling. The reality is that both methods have ideal uses.
 
KiteGen rightly points out that two lines provide useful redundancy to prevent cross-country breakaway. Such safety & reliabilty wins may be a decisive regulatory advantage. A severe problem with single anchor AWECS is the wide scope required, resulting in sprawl without density. A single line cannot overcome this problem, even with kite trains. Single lines also are wasteful of control systems, with each unit requiring stand-alone support instead of sharing.
 
KiteLab has discovered that multilines are easily "staked-out", spread roughly as wide as the kite part is tall. So imagine a string tetrahedron with its apex in the jet stream. The three lines can be thinner than a single equivalent line & overall aero downforce is reduced by those tethers set downwind. The upper part stays more or less in place instead of hunting over a wide area.Bow-tie twist is eliminated by staking out. Furthermore, lines can have kite elements all along them, making power or adding lift, & multi-line lattices naturally host maximal kite density. A crosswind kite arch already shows the advantage, even as just "two lines". One can really fill the sky with advanced multiline techniques.
 
The truth is that every common kite farm concept is in fact multiline (multiple single lineAWECS) if not optimally so. The real disagreement is whether to crosslink at altitude. KiteLab advocates large multiline kite lattices as the ideal method to run many close-spaced autogyros (or kiteplanes) up & down along set lines, so each rotor also has a line running upward from its hub, as well as down. KiteLab Ilwaco experiments show the small added drag of these multiline methods is seemingly far out weighed by the advantages cited.
 
daveS
Group: AirborneWindEnergy Message: 3420 From: dave santos Date: 4/20/2011
Subject: Survey of US Midwestern AWE Research (Pt. 1, Nebraska- "Furry" of th
Something strange is happening across America; ordinary folks are undertaking fundamental kite research with whatever is at hand with spactacular results.
 
This rockin' clip shows doubters the brutal power of the PlaySail concept, apparently spontaneously reinvented by kids, who may even have sincerely believed they had created "The Biggest Kite in the World". "Manlifting" & "Kitekilling" are featured, with an unusually effective two-line bridle arrangement possibly unknown in the George Peters PlaySail lineage-
 
 
 Next: Survey of US Midwestern AWE Research (Part 2, Texas- High Alitude Kite Trials, with Beer)
Group: AirborneWindEnergy Message: 3421 From: Bob Stuart Date: 4/20/2011
Subject: Re: Survey of US Midwestern AWE Research (Pt. 1, Nebraska- "Furry" o
That vid title - "A windy day in Nebraska" reminds me of another saying from there:  "On a nice ca'm spring day 'round here, you can still fly a cast-iron kite."

Bob

On 20-Apr-11, at 5:40 PM, dave santos wrote:


Group: AirborneWindEnergy Message: 3422 From: dave santos Date: 4/20/2011
Subject: Survey: Midwestern AWE Research (Pt 2, Texas High Alitude Kite Test
The main US Midwestern AWE Survey finding is that the Natives of Tornado Alley are restless, even if incapable of a Manhattan Project as Dr. Marchitti predicts; but they are still gotta fool with kites. Here one encounters the most monstrous wind on earth, where surface windspeed in an F5 is double jet stream, unreal power cubed (
 
This next case is of operational high altitude research based not far from where this report is written (Austin, Texas). Once again, the key was material at hand (lots of fishing line & beer). The experimental platform was a 3USD Cinderella delta kite (KiteLab Austin has two).  This kind of world-dominant toy delta kite was first developed over sixty years ago in South Texas (Gayla/Pharr) at the bottom tip of the Alley. The improvised multi-spooling electric reel in the video is uncannily like KiteLab's (which is missing...). A commentator unfairly supposes these Texans fail to apply the "Pythonorean" Theorem in their altitude claim. Human Factors experts cannot fail to note urination (noise) during the flight sequence (to prevent ruptured bladder). That the kite was "shaped like a gun" would go entirely unobserved in places like the UK. The comment that "Benjamin Franklin would kiss my ass (to see this)" is a properly respectful boast in these parts. Utimately, the police had no clue who was researching over Walmart. The main scientific expense was cheap cold beer. VC investor advice- buy the next six-pack.
 
 
 Next- Control Survey: Florida Amateur AWE Research- High Voltage Kiteline Near Thunderstorm Experiment, with vintage "old hippy" Dean Jordan Deltas. 
Group: AirborneWindEnergy Message: 3423 From: Pierre BENHAIEM Date: 4/21/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE
Hi Grant,

Great post.What is your opinion about this:"Furthermore, as the cable becomes more aligned with the vertical the cable drag increases, requiring larger kites to compensate." ,p.12 Long-Term Laddermill Modeling for Site Selection - kyoto ... .
Can be it a problem for a very long cable near the vertical (even without or little crosswind motion)?
 
PierreB 




Group: AirborneWindEnergy Message: 3425 From: Pierre Benhaiem Date: 4/21/2011
Subject: AWE to take the place of conventional wind turbines

HAWE is a field for AWE or perhaps for non or partially airborne light structures (some configurations of Doug'Superturbine and perhaps other configurations to come).

But in contrast before the exploitation of really HAWE ,AWECS could be studied to take the place of conventional wind turbines with the advantage of lesser cost and weight,and visual obstacles,and that with the same limit of altitude (under 500 ft).It is a possibility for commercial development of AWECS before the solutions on bottlnecks of both the great length of tether (drag,weight,and also losses for flygens) and aerial rules (FAA) in altitude.

My idea is searchers and companies should realize quickly and step by step (in altitude) commercial and (now) limited AWECS,then invest founds to lift.

Steps can be:

1) little AWECS like Manual FlygenKite 

2) Transportable AWECS

3) As conventional wind turbines and off-shore if possible (the same working height, the same power).FlygenKite is also working on this field.

4) Really HAWE (200 to 400 m for crosswind flygens,more for crosswind reel-out-in,more for autogyro mode in reel-out-in scheme...)

5) Jet Stream

Pierre  

 

Group: AirborneWindEnergy Message: 3426 From: maccleery Date: 4/21/2011
Subject: Re: Airborne Wind Media Coverage
Recent airborne wind activity:


RTC Magazine: Advanced Controls Enable Airborne Wind Power Generation

3-minute presentations by KITEnergy and WindLift:
Green Engineering Grant Recipient Videos

WindLift quote in NI News Release: National Instruments Announces 2011 Green Engineering Grant Program 

Airborne wind featured in Earth Week webcast keynote: Extreme Green Engineering: Making Clean Energy Cheaper Than Fossil Fuels 







Group: AirborneWindEnergy Message: 3427 From: Grant Calverley Date: 4/21/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE
Hi Pierre,
This is really a Dave Lang question but I will try and make some sense of it.
 
I think it might be that the sentence is a bit out of context or perhaps a translation problem. It is not very clear to me either.
 
What I think they  may be referring to a fixed length of tether.  Call it 1000 meters long.  If you look a both extremes, a horizontal 1000 meter long tether and a vertical 1000 meter long,  the vertical one will have much more form drag and similar surface drag then the one that is laying down horizontal, it experiences only surface drag and a very tiny tiny bit of form drag.
 
In the same paragraph you have these sentences which make sense if you consider the mix of form and surface drag the tethers are experiencing.

"It shows that for a fixed cable angle, increasing the kite altitude leads to a decrease in performance. This is due to the increase in cable length and therefore cable drag." (= more form drag and more surface drag) "Similarly, fixing the kite altitude and increasing the cable angle results in an increase in cable length and decrease in performance. " (= almost the same form drag plus more surface drag)

I may be reading this wrong still.

Grant


 
Group: AirborneWindEnergy Message: 3428 From: Grant Calverley Date: 4/21/2011
Subject: Re: Single v. MultiLine AWECS
Hi Dave
A couple of points to add to this multi line tether discussion.
 
SkyMill does not have the same runaway kite problem as kite wings and soft kites.  If there is a tether problem or break the skymill will come down just like a rock or targeted smart bomb.  If added safety is needed you could add a parachute that opened near the ground. So for SkyMills two line redundancy is not very helpful assuming it is offshore or over some desert area.
 
Mutltiline control or arrays are fine, I just think jet stream high arrays are going to be a tough nut to crack and certainly you can't fly to jet stream levels with any sort of high crosswind speeds needed by kite planes if it means dragging the tether around as well. Not to say there is not still allot of room for innovation in these areas. it is still a wide open field.
 
Consider this rope value table
 
Say you want a line that will take 207,000 kilos of breaking tension so you pick the 52 mm line.
If the line is 10,000m vertical that gives you a form drag area of 500 sq meters. Now try and imagine what sort of a kite plane wing that could drag the top half of the 500 sq  (250 sq) meters of form drag at even 180 km an hour. It would be a very big wing indeed. That is like dragging the area of a large house around behind a 747.  I think traditional crosswind flight is wishful thinking at jetstream altitudes.  It works at 500 to 1000 meters and is advertised as 2x as good as HAWT, is that good enough?
 
SkyMill gets its cross wind power out of the rotor motion and gentle cross wind shunts at about 80 kmh so the tether drag is manageable even at 10,000 meters. SkyMill wastes much potential power at these heights and tether lengths but in the end it all comes down to ROI.
 
Your tripod lines might work but the drag penalty is considerable if you go high.
Consider to get the same 207,000 kilos breaking strength you would need three lines at 30mm (75,000 kilos each) with a total form drag area of 90 mm. That is like 900 sq meters of form drag vs the 500 meters above.  In reality any one of the three tethers might at some point need to take the full 207,000 kilos so you would really need closer to three 52 mm lines to do the same job.  That is 1500 sq meters of form drag surface area instead of 500sq m. Could be done with lifter kites but does that work well for the ROI when the line is one of the most expensive elements?  The same type of issues apply for kites that run up and down leader lines from pilot kites above.  Another way of looking at it is if you were to decide the three lines with 90mm of drag was acceptable why not consider a single 88 mm rope with a whoping 662,000 kilo breaking strength? ok well it is a bit heavier but any ways food for thought.
 
As far as line drag goes in general it seems to favor scaling up to larger sizes of single line if you can lift them.
 
Grant Calverley
 

360-378-6186



Group: AirborneWindEnergy Message: 3429 From: dave santos Date: 4/21/2011
Subject: Re: Single v. MultiLine AWECS (gigawatt strategy)
Grant,
 
You well-frame core problems that KiteLab Group R&D has solved. There's lots of credit to go around, but JoeF, Wayne, DaveL, Kay, DaveC, DeanJ, Lee, Gaylord, Harry, Pierre; well this list could go on & on of those who contributed critical resurrected art & inventive leap, yourself included.
 
The established solution to easily carry line all the way to the tropopause is an eddy or ohashi kite train. Its been proven again & again for about a century & even been done by school kids. The US Govt routinized high altitude kite operations before WWI, with a national network of meteorological kiteports, & so did several EU countries, in a little known corner of history. HAWE is so doable based on classic kite methods, a new age of sailing in the sky.
 
A triangulated lattice that keeps place, with self orienting eddy & ohashi rigged kites all over, is a suitable scaffold  from which to host many turbines (including autogypros) or kiteplanes of all kind flying tight patterns on short leashes from halyards. About half of the tethers to the ground in these isotropic structures actually angle to windward for some upforce offseting downforce by other tethers. Don't forget the coolest trick of all; tug a high altitude mesh in small circles by phased tugs from around the anchor rose & it continues aloft indefinitely in calm. All generator/motor function is industrial COTS (not aerospace) & stays on the ground. Even launching & landing need not be a big deal by cascased sequences of metastable states.
 
This is true MegaEngineering compared to the biggest rigid single wing or rotor AWECS imaginable. Consider that you can also fly a mesh of autogyros on a grand scale, but the common idea of single line systems just doesn't promise to scale to gigawatt as well as 3D dense arrays will. Parachutes are an avoidable burden & cost with soft kites or redundantly suspended masses.
 
Its been a wonderful in recent years as all the needed ideas gelled; anyone who gets them joins a party,
 
Cheers,
 
daveS
KiteLab Group CTO 
 
 
 
Group: AirborneWindEnergy Message: 3430 From: Pierre BENHAIEM Date: 4/22/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE
Hi Grant,

Thank for the explain.Following another question:is form drag really identical if the vertical (sine) is the same for two tethers in comparison but the length of one tether is higher and so its angle is closer to the horizontal?It seems a component of negative lift could be integrated due to the angle in front of wind (the question is for all sort of AWECS).Simulations and experiments of tether drag according different (static,or crosswind with variations of angle,and also according to possible profiles of tether) configurations remains a big field of research.

Note:the kite helping to carry the tether and situated above the kite power DaveS mentions as a solution can be a problem during reel-in phase.

PierreB



Group: AirborneWindEnergy Message: 3431 From: dave santos Date: 4/22/2011
Subject: Realistic Tether Dynamics
These are notes bearing on Pierre's recent tether questions-
 
There are interesting high altitude tether conditions & dynamics omitted from most of AWE's crude numerical models. Simple models do give helpful indications when the sea of ignored factors tend to cancel each other, but far greater caution is required further along the engineering cycle (to validate all Design Loads Cases).
 
High altitude tethers hardly resemble the straight line of a given angle presented in simple models, but are catenaries. The lower part tends to the horizontal; the upper to vertical. Only at one point is the average angle found. The wild swings in line tension & pattern of gusts & lulls create a lot of operationally significant dynamics missed in simple models.
 
A wind gradient is often included in the simple models, but usually as a single idealized curve. Real wind is capricious & the gradient can even be highly reversed by an LLJ, with far stronger flow below. Hardly anybody's model includes the common Coriolis driven Ekman Spiral, which can appear intensified, masked, & even completely over-ridden, with a fully reversed hodograph. Its the most common condition, in the Northern Hemisphere, to see a high flying kite twisted counterclockwise from its general tether direction, but who is modeling this?
 
Then there endless issues of tether materials, construction, harmonics, etc., especially with massey conductive cables or "high" frequency mechanical pulsing, fast moving loops, etc.. Multi-tether systems of  very diverse tethers in one AWECS have hardly begun to be modeled.
 
The lesson is that simple models & early theory do not predict all the important dynamics: that persistent testing & close observation is required to discover unsuspected behaviors & inform the improved kite tether models of tomorrow. A fine scale method to gain high altitude experience is to seek out remote places & fly tiny kites very high for many hours in all conditions. 
Group: AirborneWindEnergy Message: 3432 From: Grant Calverley Date: 4/22/2011
Subject: Re: Autogyro and turbine mode [was: Re: [AWECS] Re: Open Source AWE
Now this really is a Dave Lang question. Tether dynamics are very complicated.  I think the core question is the form drag of an ellipse (cross section of the the sloped tether) the same as a circle if they both have the same width projected to the wind.  Then you add in the extra surface drag, lift, and lift induced drag and the downward windage on the sloped tether .   Or you go fly a kite like Dave Santos suggests and get out your fish scales and seek what you can find out.
Grant Calverley
360-378-6186



Group: AirborneWindEnergy Message: 3433 From: Joe Faust Date: 4/22/2011
Subject: Lateral veering (LV)
  April 20, 2011, Wed.   While in the pool:  I saw clearly how VAWT tether segments could cause  lateral veering (LV) of the tether away from center; the direction left or right could be set by the form of the tether segment. This lateral veering (LV) could be used for kite tree branching. At a branching have opposite-parity tether segments while using same-element kites on the two branches.  This adventure still uses centrally windward stable kites, as the veering tether does the work of separation. The lower tether inclination is lowered by the drag of the working LV tether segments.
Cost of branching via LV?.... CoB.
  This thread is dedicated to the study, analysis, development, and description of explorations and applications of in AWECS of lateral veering (LV) via any device:

LV of tether-set members
LV of tail-set members
LV of laundry-set members (laundry of wing elements, tail elements, tether elements, or resistive set elements)
LV of resistive-set members
LV of wing element members   [The much-discussed wing LV involves such as cross-winding via control steering units and control lines and also passive LV mechanisms. Full explication for open source is yet to be for these methods. ]

Benefit anticipations regard tree formation, array construction, mesh management, lattice options, ...

LV costs, but target gains may be worth having LV.

Aspects incomprehensively started:
Stable LV. Stable unilateral LV (just left of windward or just right of windward).
Controlled LV (amount, lateralization choosing, rate control, timing)
Uncontrolled LV.
Unexpected LV.
=========================
Balloon trajectory control system
Kim Maynard Aaron
Patent number: 6402090
Filing date: Jun 29, 1998
Issue date: Jun 11, 2002
Application number: 9/106,563


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

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

Disclosure: Perhaps others have found the same, but I present an option that has been occurring in my explorations: tether segments that are swiveled top and lower and are S formed for autorotation for stabilized LV set one way for left LV and set oppositely for right LV; think kite arch rotating ribbon kite like versioned in SkyBow, but instead sky-anchor one end for tether continuation while the lower end goes to resistive-set elements to get LV functionality with left parity or right parity depending on choice of the S formatted tether segment.  EKS invites 10% of product sold for the LV function; thanks.

It is to be mentioned here that at HAWP Conference 2009, Wayne German presented a strong interest in LV; his trophy to several people at the conference involved LV intimation via a pendulum process in his sculpture. He is also invited to this study thread.
~JoeF

==================================================
To veer: to let out
To LV: to let out to the side of wind direction.See related file: http://www.energykitesystems.net/Kites/RibbonBowArchRotators/index.html
==================================================
Group: AirborneWindEnergy Message: 3434 From: Dave Lang Date: 4/22/2011
Subject: Re: Realistic Tether Dynamics
If a good tether dynamics model is combined with a good aerodynamics model of a slender-cylinder (representing an element of tether), then most of the complexities that DaveS alludes to (that may plague grossly simplified models) are automatically addressed.

DaveL



PS.  DaveS, could you explain more fully/elaborate on....

At 7:36 AM -0700 4/22/11, dave santos wrote:
Group: AirborneWindEnergy Message: 3435 From: dave santos Date: 4/22/2011
Subject: Re: Realistic Tether Dynamics
DaveL,
 
No one seemingly has presented a realistic wind model that covers all (or even most) relevant conditions to input into a good tether analysis tool like yours. Some have used random noise to simulate turbulence, some have considered a special case or two, but the micrometeorological side of AWE models is grossly underdeveloped.
 
I'm not sure what to add to the previous note, but a common sort of windfield gradient assumption is like "a doubling of velocity with every five-fold increase in altitude". Common nighttime inversions disobey this sort of simplification. A common reversal of the wind gradient is when a local katabatic drainage wind slides downslope in a thin surface layer when the sun stops heating the slope. Even a very gentle slope can develop a strong flow.
 
A adequate semantic model of local wind could consist of hundreds of such cases. I have noted a few dozen so far,
 
daveS
 
 
Group: AirborneWindEnergy Message: 3436 From: dave santos Date: 4/22/2011
Subject: Re: Airborne Wind Media Coverage
JohnO,
 
This thread is Cc:ed to the Forum as of general interest. Thank you for noting the philosophical divide in AWE R&D that predicts how the subject gets reported. Brian is quickly getting up to speed as to the many schools of thought. Its natural that PR driven venture starts under the AWEC model have an initial mind-share advantage, no matter what the ultimate winning solutions might be.
 
I am in Austin at present & will be meeting with Brian. We will go over the curious politics & technical issues in specific detail, but the quick picture is that a preponderance of experienced aerospace veterans in AWE circles are concerned that certain poorly-qualified players are using hype rather than merit to maintain investment interest. These veterans also tend to support a class of solutions overlooked in most reporting (high inherent stability, low complexity, low capital cost, etc.). While National Instruments' formidable offerings can be easily misused by a hype-driven player to create false value, a better use of these test-engineering tools is to do basic science, especially in the comparative evaluation of competing fundamental concepts conducted by third parties like NASA & academia.
 
There is a far bigger opportunity for NI than a trickle of orders from AWE starts. Even if any such start triumphs in the new energy market, NI has no automatic equity in the historic success. NI has the depth & resources to proactively enter the AWE field with a spin-off program or venture that develops to the specific "clean-room" standards of certified avionics, as well as energy instrumentation & AWE manufacturing automation. It can dominate these niches, whatever winning configuration emerges from our race. The back-flow of experience would enhance its core business & the vast new markets created could take NI to ultimate greatness. While the window of opportunity may be quite narrow, NI clearly sees the potential of AWE & has the executive moxie to act.
 
Speaking as a Native Austinite, its great to see NI doing so consistently well over the decades,
 
daveS
 

From: Hardensoft International Limited <hardensoftintl@yahoo.com
Brian,
Thanks for your subject links.
Permit me to say here that your report on AWE seems skewed in favor of Joby-led AWE Consortium without as much as a mention of the public, open, co-operative styled Airborne Wind Energy Industry Association (AWEIA International - www.aweia.org ).
It will interest you to know that the open Yahoo Forum is part of the AWEIA efforts in furthering the rapid development of Airborne Wind Energy globally. I think AWEIA deserves a better mention as do the continuing efforts of Mr Joe Faust(www.energykitesystems.net) & David Santos Gorenna-Guinn of KiteLab Group.
Regards.
John Oyebanji
President-protem, Airborne WInd Energy Industry Association (AWEIA International)


Group: AirborneWindEnergy Message: 3437 From: Bob Stuart Date: 4/22/2011
Subject: Re: Single v. MultiLine AWECS
How about using single lines, with all kite-control functions provided by flight control surfaces with servos, just like model aircraft?  A small on-board generator would provide the power, and the brains could be either on board, or using radio control.

Bob Stuart

On 20-Apr-11, at 1:34 PM, dave santos wrote:


Group: AirborneWindEnergy Message: 3438 From: Joe Faust Date: 4/22/2011
Subject: Re: Lateral veering (LV)

Rough sketch of LV on elementary branching tether set in small-count-branched tree:

 

Group: AirborneWindEnergy Message: 3439 From: dave santos Date: 4/22/2011
Subject: Re: Single v. MultiLine AWECS
Bob Wrote-
How about using single lines, with all kite-control functions provided by flight control surfaces with servos, just like model aircraft?  A small on-board generator would provide the power, and the brains could be either on board, or using radio control.
 
===============
 
Bob,
 
Its certainly feasible & many plan the RC APU approach, but the possible disadvantages are many-
 
-More failure points
-Airborne failure points
-Increased mass aloft
-Required actuation force reserve = added mass & power required aloft (compare with "tugboat winch" on ground)
-Radio link interference potential (ground override will be an FAA reg.)
-Etc.
 
With a giant array at high altitude, direct mechanical actuation from the ground in realtime is aided by the slow gross dynamics.
 
Airborne APUs can be minimally employed to drive nav lights & transponders with failsafe redundancy.
 
daveS