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.

http://markeymachinery.com/history.asp

Markey Machinery

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

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")

 

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/

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

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".

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

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

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

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

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

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.

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."

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 

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  

 

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 

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

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

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.

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