Messages in AirborneWindEnergy group.                           AWES17043to 17092 Page 235 of 440.
Group: AirborneWindEnergy Message: 17043 From: dave santos Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17044 From: dave santos Date: 2/26/2015
Subject: Re: Radio telescope mount as solid analogue for isotropic expansion

Group: AirborneWindEnergy Message: 17045 From: Rod Read Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17046 From: Rod Read Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17047 From: Rod Read Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17048 From: Rod Read Date: 2/26/2015
Subject: Re: Radio telescope mount as solid analogue for isotropic expansion

Group: AirborneWindEnergy Message: 17049 From: dave santos Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17050 From: dave santos Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17051 From: dave santos Date: 2/26/2015
Subject: Re: Radio telescope mount as solid analogue for isotropic expansion

Group: AirborneWindEnergy Message: 17052 From: benhaiemp Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17053 From: dave santos Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17054 From: benhaiemp Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17055 From: benhaiemp Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17056 From: benhaiemp Date: 2/26/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17057 From: benhaiemp Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17058 From: Rod Read Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17059 From: Rod Read Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17060 From: dave santos Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17061 From: dave santos Date: 2/27/2015
Subject: VentAir's Early Concept

Group: AirborneWindEnergy Message: 17062 From: Rod Read Date: 2/27/2015
Subject: Re: VentAir's Early Concept

Group: AirborneWindEnergy Message: 17063 From: dave santos Date: 2/27/2015
Subject: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17064 From: Rod Read Date: 2/27/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17065 From: snapscan_snapscan Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17066 From: dave santos Date: 2/27/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17067 From: dave santos Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17068 From: Rod Read Date: 2/27/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17069 From: dave santos Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17070 From: dave santos Date: 2/27/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17071 From: David Lang Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17072 From: dave santos Date: 2/27/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17073 From: dave santos Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17074 From: David Lang Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17075 From: Pierre BENHAIEM Date: 2/27/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17076 From: Rod Read Date: 2/28/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17077 From: dave santos Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17078 From: benhaiemp Date: 2/28/2015
Subject: Re: Fabric Scaling?

Group: AirborneWindEnergy Message: 17079 From: dave santos Date: 2/28/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17080 From: David Lang Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17081 From: dave santos Date: 2/28/2015
Subject: Re: Fabric Scaling?

Group: AirborneWindEnergy Message: 17082 From: dave santos Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17083 From: Rod Read Date: 2/28/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17084 From: David Lang Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17085 From: dave santos Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17086 From: dave santos Date: 2/28/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17087 From: David Lang Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17088 From: snapscan_snapscan Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17089 From: Pierre BENHAIEM Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17090 From: dave santos Date: 2/28/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17091 From: Pierre BENHAIEM Date: 3/1/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17092 From: Pierre BENHAIEM Date: 3/1/2015
Subject: Re: Torque



Group: AirborneWindEnergy Message: 17043 From: dave santos Date: 2/26/2015
Subject: Re: Torque
Rod wrote (regarding torque ladder): "Nah it's never been meant to go there. Get a grip Dave. 
This is a low level only component. An enabler. You may stop ranting on now oh holy one."

This is where it seemed that "low-level only component" was your "finding or conclusion" seemingly consistent with Gordon, et al.


On Thursday, February 26, 2015 11:08 AM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17044 From: dave santos Date: 2/26/2015
Subject: Re: Radio telescope mount as solid analogue for isotropic expansion
This seems closely related to an old forum similarity case based on the Arecibo radio telescope, focused on its tri-tether (focal) analog. Its been proposed a pilot-kite lazy-jack (tensile whipple-tree) can hold up an isodome lattice, pulling up preferentially on the LE-

 


On Thursday, February 26, 2015 2:26 AM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17045 From: Rod Read Date: 2/26/2015
Subject: Re: Torque

Yes and that was consistent with the torque ladder method being "discussed" in that thread you pulled the excerpt from.
Torque however can be transferred with other methods such as linked rings. Or even run off to the side as a driven rope loop line.
So I can't put any limit on how high a torque device will work at.. nor yet do I know the detail of any limiting ratios sorry e.g. length to power ratio
So
I'll stand by the text excerpt as was.

Group: AirborneWindEnergy Message: 17046 From: Rod Read Date: 2/26/2015
Subject: Re: Torque

Well until i know more about its operation, torque ladder is definitely staying low level where i use it.
Come on wish me luck.

Group: AirborneWindEnergy Message: 17047 From: Rod Read Date: 2/26/2015
Subject: Re: Torque

This seems ridiculous again.
Pierre didn't even introduce torque ladder to this thread. Why argue it here torquophobe?
Has Kitelab done torque ladder testing?

Group: AirborneWindEnergy Message: 17048 From: Rod Read Date: 2/26/2015
Subject: Re: Radio telescope mount as solid analogue for isotropic expansion

Hmm I see what you're getting at. But...
No.
The mount details on the back of the dish are key here.
The load spreading helps maintain uniformity in dish shape... A reliable structure surface despite different loading conditions.. That's the key linking principle I was hinting toward.
Put it upside down to make a solid raised controllable tethered flying net.

Group: AirborneWindEnergy Message: 17049 From: dave santos Date: 2/26/2015
Subject: Re: Torque
Rod,

The question is not whether the torque ladder can be made to work marginally (it can), but whether it competes against safest and highest-power-to-weight aviation criteria.

I really do wish you luck (over Christian's objection to wishing for luck). In particular, good luck to you (and us all) quickly converging on AWE's early-classical forms, as a fellow "oh holy one". 

One thing at least is clear; if AWES of any kind saves the world, there will be many skeptics,

daveS


On Thursday, February 26, 2015 11:51 AM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17050 From: dave santos Date: 2/26/2015
Subject: Re: Torque
It was presumed that the Daisy Pierre referenced was intended to drive the torque-ladder, itself on-topic. KiteLab tested driveshafts (torque tubes) and tensioned twisted rope, and found these poorly scalable compared to common rope-pumping or rope-driving. The ladder was seem as a-priori dangerous and costly to scale, with high aerodrag to boot. It was hoped you could provide some tangible results for the ladder case, to help settle conflicting claims.


On Thursday, February 26, 2015 12:19 PM, dave santos <santos137@yahoo.com
Group: AirborneWindEnergy Message: 17051 From: dave santos Date: 2/26/2015
Subject: Re: Radio telescope mount as solid analogue for isotropic expansion
The lazy-jack pulley whippletree is proposed to allow a soft dome to hold its ideal shape, to convert solid structure into tensile versions with similar geometry. In the Arecibo model, the concrete parabolic is imagined upside down, made of fabric ("drop-stitch" bridled within its area), and tilted downwind to its AoA.


On Thursday, February 26, 2015 12:02 PM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17052 From: benhaiemp Date: 2/26/2015
Subject: Re: Torque
I  mentioned also crosswind kites (Ampyx, Enerkite...) by introducing the present topic, that about tangential force existing in different methods. I saw Daisy with several stages as a sort of torque-ladder. But a very recent analysis  shows me a (maybe already mentioned) possible kinship between ladder-torque and catenary Catenary - Wikipedia, the free encyclopedia .    

Each stick of ladder involves a different trajectory of rope, favoring torque, and probably favoring a higher ratio height/diameter I mentioned. Sticks can be replaced by rotors (as it is shown in Serpentine patent, but with ropes here). In case of Daisy with several stages (also as big levels of global torque-ladder), an intermediary torque-ladder can be added between stages to improve transmitted torque. So R&D about torque-ladder looks perfectly justified.


PierreB 

 
Group: AirborneWindEnergy Message: 17053 From: dave santos Date: 2/26/2015
Subject: Re: Torque
Sadly, catenary-sag of a rotating torque-ladder, due to gravity and wind pressure, is a critical power-dispersive stress-concentrating factor. A torque-ladder would work best in a zero-gravity vacuum, with no catenary curve. A sag curve is also the nominal geometric state for non-rotating pumped or driven tethers in wind and gravity. Such a sag curve does not help, nor hurt too much. Note that kiteline "catenaries" are more complex curves that only approximate true catenaries.

Shear-forces are not promoted in thin string when pumped or driven, compared to unstable shear-forces lurking in similarly lightweight torque transmissions, in wind and gravity. The AWES designer should ask this question (regardless of any catenary issue)- is torque transmission the lightest safest cheapest option for a long distance mechanical transmission? From both AWES testing and theoretic perspectives, the answer is increasingly well known: "no".




On Thursday, February 26, 2015 2:02 PM, "pierre.benhaiem@orange.fr [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17054 From: benhaiemp Date: 2/26/2015
Subject: Re: Torque

Yes, but let us make some comparison with the other well known ground method as yoyo (single unity, reel-in/out), or even reciprocating reel (two unities). The kite goes down by 1/3 wind speed, losing power by 2.25 times (3² / 2²) then globally by 2 times by recovering. So torsion transmission could be yet  interesting by being 0.25 % efficient.


PierreB
Group: AirborneWindEnergy Message: 17055 From: benhaiemp Date: 2/26/2015
Subject: Re: Torque

"So torsion transmission could be yet  interesting by being  25 %  [correction] efficient."


PierreB
Group: AirborneWindEnergy Message: 17056 From: benhaiemp Date: 2/26/2015
Subject: Re: Torque

Another corrections and precisions of my precedent post:

"The kite goes downwind by 1/3 wind speed, losing power** by 2.25 times (3² / 2²)* then globally by 2 times by recovering. So torsion transmission could be yet  interesting by being 25 % efficient.


PierreB

* force: the square of relative wind speed (wind speed less kite motion)

** power: force x 1/3 wind speed
Group: AirborneWindEnergy Message: 17057 From: benhaiemp Date: 2/27/2015
Subject: Re: Torque
About ladder to falco power test

 

, trying to make some analysis. Note 48 W output Rod mentions is roughly 1/3 of power input (161 W); due to other losses (bike, emotor system) it is quite a good result (compare with 1/4 or 1/5 for reel-in/out due to both recovering and loss of relative wind). Measure of axial force (traction) is needed to refine results.

How a so good result is  possible? I am going to try to risk an explanation.

Without sticks cosine is near zero, the same for power. With sticks one has far greater cosine between two sticks, then  cosine X cosine...,n sticks ( http://www.analyzemath.com/trigonometry/trigonometric_table.html) , and in a helical shape. 

So if sticks are replaced by rotors (in a way not too penalising  due to drag of turning ropes), rotors should not turn at the same time but with a gap.


PierreB
Group: AirborneWindEnergy Message: 17058 From: Rod Read Date: 2/27/2015
Subject: Re: Torque
I made some power today via PL lifter, Daisy kite, Torque Ladder & Falco ewheel.

ok, only a tiny bit so far.
There are some obvious looking (possibly wrong) tweaks to this new Daisy ring needed.
It was all a bit fiddly to set up.
The Daisy drivers didn't hold so well off the wind. Too much lift in the PL single skin single line lifter, so it had to be retarded at the inline bearing to keep the rotation flatter to the wind.
I set the drivers with too much pitch I reckon... Not using apparent wind enough.
The back end of the new ring is very hollow and too loose compared to the old one...
I may mix and stack them together for the next test.

I'll get some video of the test up soon.

Rod Read

Windswept and Interesting Limited
15a Aiginis
Isle of Lewis
UK
HS2 0PB

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17059 From: Rod Read Date: 2/27/2015
Subject: Re: Torque

Daisy making Power: http://youtu.be/2kfpTXT9abs

Torque working.
And not too deadly yet.

Group: AirborneWindEnergy Message: 17060 From: dave santos Date: 2/27/2015
Subject: Re: Torque
Cool demo, Rod. Operating from a mud pit is a nice touch.

Pierre, comparing torque efficiency to reeling AWES is just not enough of a boost, since a large torque drive is exponentially less efficient compared to the modest loss of downwind reeling efficiency. The prediction that drive shafts will not scale up under square-cube law remains the dominant factor. Then there are all the non-reeling tensile methods (crosswind drives) to compete against.

Note thatl EU teams with reeling architectures are simply flying far higher, safer, and cheaper in better wind than any torque drive ever seen, as predicted by Galileo's fundamental engineering scaling law.




On Friday, February 27, 2015 8:29 AM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17061 From: dave santos Date: 2/27/2015
Subject: VentAir's Early Concept
VentAir brings fresh enthusiasm to AWE, even though its initial concept faces well-known technical challenges. Disclaimer- Edmund Villarreal is from the South Texas Rio Grande Valley, from the same tiny spot on the US-Mexico border, where the modern detla kite was invented (Gayla Kites), where the soaring World Record Encampment* is based, and where my mother's family is from, and we are distantly related. kPower is hoping Edmund will study the AWE field diligently and harness his marketing talent in service of Open-AWE, as our industry continues to consolidate around leading methods-



* The model for the Texas AWE Encampment
Group: AirborneWindEnergy Message: 17062 From: Rod Read Date: 2/27/2015
Subject: Re: VentAir's Early Concept
This new utility / toy looks able to fly fast to a remote location, perform some precise delicate manoeuvre, and return.

It'd be nice if we could prune old worn kites from the top of a growing working kite cluster... As we fed in new kite roots from the bottom.
Chopping topology or kite topiary ?

Rod Read

Windswept and Interesting Limited
15a Aiginis
Isle of Lewis
UK
HS2 0PB

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17063 From: dave santos Date: 2/27/2015
Subject: Regenerating Kite Structure
Rod wrote: "It'd be nice if we could prune old worn kites from the top of a growing working kite cluster... As we fed in new kite roots from the bottom.
Chopping topology or kite topiary ?" *


The early AWES Forum reviewed ideas along this line. One idea was flying-rope or ribbon wing flying right out of the factory continuously, with the oldest part looping thousands of miles back into the factory to be recycled. A DIY variant is someone at a sewing machine with a growing ribbon wing arch flying directly from the sewing table. Another idea is laminated kite membrane, where new thin-film layers are pasted on one side as the other side wears away; like living skin. Rope could also be renewed by vast (planetary-cale) service loops.

In current early practice, the goal is 100% recyclable wing and string, which is easy for the softkite  "polymer only" AWES design path, but not for complex kiteplanes, rigid-rotors, control-pods, etc. (CC+ Open-AWE IP-Pool).

-----------------------
* Time flow processes are fundamentally topological. Topiary similarity-case implies overgrowth and littering in our context.

 
Group: AirborneWindEnergy Message: 17064 From: Rod Read Date: 2/27/2015
Subject: Re: Regenerating Kite Structure
Reuse is as good as recycle.
Say we have a stack or mesh of control pods with their kite set as a single lift points (SKysails like)
So the bridles or the lift skin get worn... don't throw the pod away. Yes trim it away from the structure and refit it.

How much power does the skysails pod need to run? What size ducted RAT trickle charger does that imply? Affect on overall L/D?
Which kite gives us as little pod print possible... could a control pod run from a microcontroller...I adjusted my PL SSSL by 2mm once before launch today to set it steady... That was not a lot of work.

Does an old net with multiple lift and gen layers need to shed a whole skin layer at a time? or just loose the odd cell kite unit here and there? Probably depends on interconnectivity of the parts.

Rod Read

Windswept and Interesting Limited
15a Aiginis
Isle of Lewis
UK
HS2 0PB

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17065 From: snapscan_snapscan Date: 2/27/2015
Subject: Re: Torque
Dave,

I have a hard time following your reasoning. I do understand the square-cube law. What I do not understand is why you believe it to be applicable to the torque ladder method. To increase the ladder length you are only scaling up in ONE dimension (not two, not three) - hence the weight will go LINEAR with the length.

Also I have gotten a copy of Gordon in the meantime but can not find his "famous declarations against torsion" in there. Would you mind pointing me to the right page/paragraph?

Your help is highly appreciated!

/cb
 
Group: AirborneWindEnergy Message: 17066 From: dave santos Date: 2/27/2015
Subject: Re: Regenerating Kite Structure
Unfortunately, thin membranes and lines do not "reuse"like other products due to the accumulated molecular damage of UV, mechanical wear, etc., which degrades material below required specifications.

Current kite machinery is not yet design-optimized by long experience, and is better donated to museums than reused like a flying milk bottle. If modern airliner and military aircraft  lifecycles are any guide, obsolescence cycles are short, and component reuse has not been a major factor. Smaller general aviation aircraft do have long lives, but they took several decades to "perfect", and live on as vintage heirlooms. Evolutionary aviation settled on birds molting their feathers, rather than reusing them.

Recyclability v. reuse remains a very clear cut philosophical divide in AWES design, with Makani representing the extreme case of poor recyclability, with hoped-for indefinite reuse cycles (between major overhauls). On the other hand, the "sell more cheap kites" economic model has the early market window. Reuse is predicted to grow in AWE, but perhaps too slowly for smart money, yet.


On Friday, February 27, 2015 1:23 PM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17067 From: dave santos Date: 2/27/2015
Subject: Re: Torque
Its untrue that you only have to scale up one dimension to scale a torque drive. If you do that, you still increase the probability of  local structural failure linearly, reducing reliability. Worse, you have only scaled a weak toy higher, an extended torque ladder can still only handle the original toy range of power (with linearly reduced reliability). To get to competative MW scale, you need large rigid ladder spars, which are penalized like the elephant bone in Galileo's original book, and would be very dangerous. Torque partisans are not worried about a torque-ladder's unavoidable low-rpm inefficiency or high-aerodrag, probably since so much bad news is hard to digest.

The shocking truth is that all AWES schemes depending on rigid structure aloft (kiteplanes, rotors, torque ladders, etc) are predicted not to scale economically. Its not just Gallileo's law, but also reflects that excess mass is toxic in aerospace design, and that most probable wind velocities for AWES are below convetional aircraft velocities. We can even now see this in terms of thermodynamic specific heat. Its a really solid finding that we were not so sure of ten years ago. Only soft-kite structure can unit-scale to many km, for proportionally far more power. Even kite farm piloting economics (pilot/MW ratio) favors avoiding the small unit scale of rigid flying parts. This is why GoogleX is likely to try to sell off Makani, but kPower is duly warning prospective investors there is not much value in the architecture, based on square-cube reality.


On Friday, February 27, 2015 1:54 PM, "snapscan_snapscan@yahoo.de [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17068 From: Rod Read Date: 2/27/2015
Subject: Re: Regenerating Kite Structure

If modern airliner and military aircraft  lifecycles are any guide,...
Then we should only build rigid wings

Evolutionary aviation settled on birds molting their feathers, rather than reusing them.
Yep,  luckily for the bird the control pod or bird body part gets reused.

Group: AirborneWindEnergy Message: 17069 From: dave santos Date: 2/27/2015
Subject: Re: Torque
Starting at page 271 of Gordon's "Structures" book is where torsion is famously critiqued in terms of excess mass-

"Nature...seems to avoid torsion like poison," is how it starts, and he goes on to make his case by explanation and examples.

 


On Friday, February 27, 2015 3:46 PM, dave santos <santos137@yahoo.com
Group: AirborneWindEnergy Message: 17070 From: dave santos Date: 2/27/2015
Subject: Re: Regenerating Kite Structure
In the Open-AWE reference case, the ground itself and ground-based actuation is "the control pod or bird body part [that] gets reused".

It can already be concluded that (re)use of land and land-based industrial COTS is maximized under our anchor-circle-based (ground-as-spar) Low Complexity AWES design. In fact, KiteShip was shopping for standard tugboat winches to actuate giant kites (when Makani bought them out and shut them down), Such common winches are rebuilt many times, for very long service lives.


On Friday, February 27, 2015 3:56 PM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17071 From: David Lang Date: 2/27/2015
Subject: Re: Torque
On Feb 27, 2015, at 3:46 PM, "dave santos santos137@yahoo.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com And this "All" includes "rotors" Who has "predicted" this?

DaveL
Group: AirborneWindEnergy Message: 17072 From: dave santos Date: 2/27/2015
Subject: Re: Regenerating Kite Structure
As it turns out, the maximal Open-AWE reuse case presented so far is to retrofit legacy utility-scale power plants as kite conversions or hybrids. Its as if a plant's destiny is to regenerate into an AWES. This is core CC+ Open-AWE IP-Pool thinking, at the civilizational level. A likely early target for reuse conversion will be a carbon-restricted coal plant in its own waste zone. Reuse would aim to create a paradise.


On Friday, February 27, 2015 4:26 PM, dave santos <santos137@yahoo.com
Group: AirborneWindEnergy Message: 17073 From: dave santos Date: 2/27/2015
Subject: Re: Torque
Galileo!


On Friday, February 27, 2015 5:02 PM, "David Lang SeattleDL@comcast.net [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17074 From: David Lang Date: 2/27/2015
Subject: Re: Torque
So what did Galileo know about rotor craft?

DaveL
Group: AirborneWindEnergy Message: 17075 From: Pierre BENHAIEM Date: 2/27/2015
Subject: Re: Torque

Earth's rotation!

 

PierreB

 

 

 

 
Group: AirborneWindEnergy Message: 17076 From: Rod Read Date: 2/28/2015
Subject: Re: Regenerating Kite Structure
Good argument, absolutely yes, ground as spar, we can't go wasting that...control lines from the ground have their drag implications though.
Open AWE has a number of reference cases to work from now.
Given that we resolved pure rag and string aloft is an ambition yet impractical ... Even if the non soft components are just small steel rings... reuse them as needed.

I had forgotten the buyout and cease of kiteship by Makani. Idiots. The poor abandoned kiteship.com google don't even release info there to explain themselves. Dicks! Grade A Dicks! That's like basic netiquette.

As a probable replacement for kiteship .... have we listed http://www.intpowertechcorp.com/
here or on energykitesystems.net yet?

Rod Read

Windswept and Interesting Limited
15a Aiginis
Isle of Lewis
UK
HS2 0PB

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17077 From: dave santos Date: 2/28/2015
Subject: Re: Torque
Yes, its rather funny that Galileo's Relativity suggests we can view a rotor as a stationary POV if we wish, with the entire cosmos orbiting.

The practical criteria presumed here is a maximal AWES rotor still conventionally rigid enough to support itself in gravity solely by its blade's cantilever rigidity. Galileo's Law predicts such a rotor will be sapped by excess mass, compared to smaller rotors. Galileo might still have underestimated how toxic excess mass is in aerospace design, but not Billy Roeseler, whose AWES (ribbon-wing blade) rotor proposal to Boeing, in the 70s was intended to overcome conventional rotor limits. German airship designers also experimented with ribbon-wing blade propellers to save weight, but the tradeoffs were less urgent that the AWE case. Sirohi's Rotor Lab at UTexas, with its UMD DNA, also has made a study of flexible rotors to transcend scaling limits and other operational factors. These are kPower's rotor domain-expert sources. We see the rigid rotor scaling problem as comparable to rigid wing scaling, under Galillean Scaling Law. The rotor hub in particular tends to become massive, just like the wing-roots of large non-rotating aircraft (disregarding motion observer POVs).

This may not be enough (public) proof for SkyMill's design team, but the stealth venture isn't offering any public counter-proof as to what they find is the conventional (semi-rigid) rotor scaling limit for an AWES, and its net power rating in most-probable wind velocities (after subtracting the power just to maintain flight). Billy Roeseler's AWES rotor scaling rationale against rigid structure remains the most authoritative public statement in AWE that square-cube law severely limits rigid rotor unit scale. Hopefully SkyMill has some key rotor-scaling knowledge everyone has overlooked ("secret sauce")!


On Friday, February 27, 2015 8:16 PM, "Pierre BENHAIEM pierre.benhaiem@orange.fr [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17078 From: benhaiemp Date: 2/28/2015
Subject: Re: Fabric Scaling?

For fabric multi-MW-scale , the kite area should be 100 (for crosswind system) or 1,000 (for stationary system) times bigger as the bigger existing kite (1,000 m²). We know 3D objects (rigid wings) scale by cube law (volume) , and 2D (soft wing) don't.

But what do we really know about fabric scaling  in multi-MW scale?


PierreB
Group: AirborneWindEnergy Message: 17079 From: dave santos Date: 2/28/2015
Subject: Re: Regenerating Kite Structure
We are swerving a bit off topic-

One way to over come actuation-line negative-lift (with an anchor-field) is to angle such lines upwind, for some positive lift. Multiple lines can be specified thinner for a comparable safety margin by redundancy against a single-line units. The ultimate way to eliminate all tether drag (which even a control pod does not do) is an arch restrained only by its wingtips (no tethers at all). Actuation lines can run within the wing-plane.

KiteShip is in a limbo, and could be revived (like Hans Solo in Carbonite). At least the principals were compensated enough to not have much cause for open complaint. We do not know the actual terms of the deal, which DaveC has insisted, without giving any details, this was not a wholesale buyout of KiteShip (but maybe was a smaller equity-play, option, or license). Dean Jordan, however, seems to have been finally compensated, grumbling vaguely about the deal, and has returned to his former kite work in Florida.


On Saturday, February 28, 2015 12:41 AM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17080 From: David Lang Date: 2/28/2015
Subject: Re: Torque
DaveS

Is an autogyro a rigid rotor?

DaveL
Group: AirborneWindEnergy Message: 17081 From: dave santos Date: 2/28/2015
Subject: Re: Fabric Scaling?
Galileo's Law still applies to soft structure, but less severely because "Rag and string" is an effective approximation of ideal lower-dimensional structure. Even though kite lines are really 3D, two of the mass-multiplier dimensions are very small, and kite membranes are also 3D, but one of the dimensions is inherently very small. To this extent, they greatly mitigate square-cube law. Tensile structure is also inherently favored by equivalent mass, by avoiding shear and bending stress concentrations. The working rule as we scale up soft kite structure is that the membrane thinness and aerodynamic wing-loading remains constant, but rope load paths are added in fractal stages to vast scale, as tensile organization like a mighty tree has stages of twigs, branches, and trunks. At some point too massive a trunk-line will not fly optimally, but this soft-kite limiting scale is beyond the vertical scale of the atmosphere (~15km high)!

It also helps that our membranes are ram-air inflated structure, and air is neutrally buoyant. We also experience wing-in-ground-effect boost at higher altitudes with vast wings, and even solar thermal and heat-of-compression boosts. While inferior rigid-structure AWES paradigms will fail to megascale, and tend to fall fatally out of the sky, the weird giant soft kite problem has been how to make them come down with kill lines. They really want to fly. Rigging 22m PLPLs as a stack, on the ground, in gusty winds, the kites seemed like loaded guns or coiled snakes (that killed Eideken), and it is a peaceful relief to launch. Rigid-wing AWES pioneers must deeply worry when flying. Their rigs have scant inclination to spontaneously fly, and seem to want to crash.

These are CC+ Open-AWE IP-Pool principles.


On Saturday, February 28, 2015 9:44 AM, "pierre.benhaiem@orange.fr [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17082 From: dave santos Date: 2/28/2015
Subject: Re: Torque

DaveL asked:"Is an autogyro a rigid rotor?"

An autogyro rotor can be designed anywhere along a soft-rigid structure spectrum (but the soft end of the spectrum is the scalable end). A  typical autogyro rotor is here called "rigid" if it is designed to hold itself in (drooped) shape at rest, by cantilevered blade structure, in normal gravity (as pragmatically defined in my previous post). Billy Roeseler's autogyro AWES concept is an example of a non-rigid rotor. kPower's looping foils and Rod's Daisy are also soft autogyro rotors. These are not self-supporting at rest.

Is all this not how you see it?


On Saturday, February 28, 2015 10:48 AM, "David Lang SeattleDL@comcast.net [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17083 From: Rod Read Date: 2/28/2015
Subject: Re: Regenerating Kite Structure
I could do with regenerating as a useful kite structure engineer.

Dave S, where you wrote...
One way to over come actuation-line negative-lift (with an anchor-field) is to angle such lines upwind, for some positive lift.
Can you please give some indication to a scheme or drawing you know of with this?
I do love the in wing plane arch control methods ... but we run into stacking , rotating, reaction speed and load complexities again.
Wind takes some big big swirls and dips. Is a singular big arch kite going down more hazardous than a breakable mesh?

Rod Read

Windswept and Interesting Limited
15a Aiginis
Isle of Lewis
UK
HS2 0PB

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17084 From: David Lang Date: 2/28/2015
Subject: Re: Torque
DaveS

…...on the subject of "whimsical discourse", and putting all of one's eggs in Galileo's "scaling basket"….wouldn't it be ironic to resurrect Galileo and magically, un-benownst to him, re-materialize him inside an Airbus 380 to witness folks therein flying rubber-band powered aircraft about, and hear Galileo say, "those little rigid wing airplanes will never scale up to any significant size" :-) :-).

DaveL
Group: AirborneWindEnergy Message: 17085 From: dave santos Date: 2/28/2015
Subject: Re: Torque
Galileo was uniquely equipped to see an Airbus as pathetically small, since he was the first modern person to see planets clearly as other worlds. We have a reducto-absurdum case against a fleet of thousands Makani M5s required to power a single large city (concept now defunct even within Makani). Fort Felker calculates that an AWES concept cannot be economic if it costs-out like current air transports. This is not whimsical thinking if the need is urgent.

We are talking about a civilizational scale energy need, so AWE soft-kite thinking is far beyond Airbus scale, not just by one order of magnitude, to roughly match power, but by two or three orders, with COTS line and fabric as the Low-Complexity AWES cost basis.

In any case, it will be fun to pit all our opposed AWES concepts to a serious fly-off, and settle all speculation.




On Saturday, February 28, 2015 2:29 PM, "David Lang SeattleDL@comcast.net [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17086 From: dave santos Date: 2/28/2015
Subject: Re: Regenerating Kite Structure
The troves of defensive-disclosure drawings contain hundreds of instances where tethers spread in all directions, including tilted upwind, for whatever purpose (transmission, actuation, etc.). All develop helpful positive lift. This is a good method where some kind of non-structural line is thicker (hose or insulated electrical conductor) and can be naturally angled upwind. Only the thin UHMWPE tether need angle downwind, and the rest can act as passive kite-killers if the primary tether parts.

In-plane control lines are not too exotic, for example, many sails have leech-lines, the Viennese curtain drawline works with just simple loops along the fabric. Muscles and tendons in bat wings are a biomimetic case.


On Saturday, February 28, 2015 1:43 PM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17087 From: David Lang Date: 2/28/2015
Subject: Re: Torque
I give up!

DaveL
Group: AirborneWindEnergy Message: 17088 From: snapscan_snapscan Date: 2/28/2015
Subject: Re: Torque
Thank you Dave, Now I understand that you apply the square-cube law to the spars - which is correct when you are talking about scaling up torque. It is not applicable however when Rod will start to scale up the length of his ladder. 

One more question on your "shocking truth about rigid structure aloft": How do you explain to yourself the fact that 99.99% of man made structures aloft are rigid? Some of them like the Airbus A380 do look bigger than an elephant to me and seem to maintain themselves in the air pretty ok.

/cb
Group: AirborneWindEnergy Message: 17089 From: Pierre BENHAIEM Date: 2/28/2015
Subject: Re: Torque

Torque-ladder can scale up keeping the proportions in length and in width.

A 6 MW-scale wind tower is bigger than an Airbus A380, and a multi-MW-scale AWES should be bigger than a wind tower (but far lighter).

 

PierreB

 

 

 

 
Group: AirborneWindEnergy Message: 17090 From: dave santos Date: 2/28/2015
Subject: Re: Torque
cb,

If Rod scales only the length of his torque-ladder, then he must still incur a reliability penalty, by the added failure points (or add mass, to maintain constant reliability. This is statistical law. Nor is scaling a low-powered AWES higher a big win. Rotating aerodrag and downforce also increase. If Gordon is correct about torsion as poison to mass-efficiency, in accord with Galileo's Law, then it makes total sense that no one can effectively get to 200ft with AWES torque-ladders, much less 2000ft.

Safety is also critical in aviation design, and a torque ladder of serious size (
Group: AirborneWindEnergy Message: 17091 From: Pierre BENHAIEM Date: 3/1/2015
Subject: Re: Torque

DaveS wrote: "If Rod scales only the length of his torque-ladder, then he must still incur a reliability penalty, by the added failure points (or add mass, to maintain constant reliability. "Yes, and torque input/output ratio will decrease (so keeping proportions in length and in width).

 

For scalability, comprising torque transmission, AWES face two different concerns: lift, where fabric wing seems favored; and power generation, where the discussion is more open (fabric, rigid, semi-rigid http://eartheasy.com/blog/2012/12/new-fabric-covered-blades-to-lower-cost-of-wind-energy/ ?).

 

PierreB

 
Group: AirborneWindEnergy Message: 17092 From: Pierre BENHAIEM Date: 3/1/2015
Subject: Re: Torque

Precision about "...AWES face two different concerns: lift, where fabric wing seems favored; and power generation..." : for some systems (Guangdong for example) power generation is included in lift, lift without any power generation concerning pilot kites as lifters.

 

PierreB