Messages in AirborneWindEnergy group.                           AWES17093 to 17142 Page 236 of 440.
Group: AirborneWindEnergy Message: 17093 From: dave santos Date: 3/1/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17094 From: dave santos Date: 3/1/2015
Subject: Re: Hello i am student from korea and i wanna know if i can get a ch

Group: AirborneWindEnergy Message: 17095 From: joe_f_90032 Date: 3/1/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17096 From: Rod Read Date: 3/1/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17097 From: benhaiemp Date: 3/1/2015
Subject: Re: Fabric Scaling?

Group: AirborneWindEnergy Message: 17098 From: Rod Read Date: 3/1/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17099 From: dave santos Date: 3/1/2015
Subject: Re: Fabric Scaling?

Group: AirborneWindEnergy Message: 17100 From: dave santos Date: 3/1/2015
Subject: Passive Barometric Kite Killers

Group: AirborneWindEnergy Message: 17101 From: dave santos Date: 3/1/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17102 From: dave santos Date: 3/1/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17103 From: dave santos Date: 3/1/2015
Subject: Re: Regenerating Kite Structure

Group: AirborneWindEnergy Message: 17104 From: snapscan_snapscan Date: 3/1/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17105 From: dave santos Date: 3/1/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17106 From: dave santos Date: 3/1/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17107 From: Rod Read Date: 3/2/2015
Subject: Re: Fabric Scaling?

Group: AirborneWindEnergy Message: 17108 From: Rod Read Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers

Group: AirborneWindEnergy Message: 17109 From: Pierre BENHAIEM Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers

Group: AirborneWindEnergy Message: 17110 From: Pierre BENHAIEM Date: 3/2/2015
Subject: Re: Fabric Scaling?

Group: AirborneWindEnergy Message: 17111 From: Rod Read Date: 3/2/2015
Subject: Bowstring geometry

Group: AirborneWindEnergy Message: 17112 From: Rod Read Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17113 From: Rod Read Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers

Group: AirborneWindEnergy Message: 17114 From: Rod Read Date: 3/2/2015
Subject: Re: Fabric Scaling?

Group: AirborneWindEnergy Message: 17115 From: joe_f_90032 Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers

Group: AirborneWindEnergy Message: 17116 From: joe_f_90032 Date: 3/2/2015
Subject: Integrated Power Technology Corporation™

Group: AirborneWindEnergy Message: 17117 From: benhaiemp Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17118 From: benhaiemp Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17119 From: joe_f_90032 Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17120 From: christopher carlin Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers

Group: AirborneWindEnergy Message: 17121 From: dave santos Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers

Group: AirborneWindEnergy Message: 17122 From: dave santos Date: 3/2/2015
Subject: Re: Bowstring geometry

Group: AirborneWindEnergy Message: 17123 From: dave santos Date: 3/2/2015
Subject: Re: Fabric Scaling?

Group: AirborneWindEnergy Message: 17124 From: dave santos Date: 3/2/2015
Subject: Re: [AWES] Integrated Power Technology Corporation™

Group: AirborneWindEnergy Message: 17125 From: dave santos Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17126 From: dave santos Date: 3/2/2015
Subject: Why UHMWPE is so AWEsome

Group: AirborneWindEnergy Message: 17127 From: snapscan_snapscan Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17128 From: Rod Read Date: 3/2/2015
Subject: Re: Bowstring geometry

Group: AirborneWindEnergy Message: 17129 From: dave santos Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17130 From: Rod Read Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17131 From: dave santos Date: 3/2/2015
Subject: Re: Bowstring geometry

Group: AirborneWindEnergy Message: 17132 From: Rod Read Date: 3/2/2015
Subject: Re: Bowstring geometry

Group: AirborneWindEnergy Message: 17133 From: dave santos Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17134 From: dave santos Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17135 From: dave santos Date: 3/2/2015
Subject: Re: Bowstring geometry

Group: AirborneWindEnergy Message: 17136 From: joe_f_90032 Date: 3/2/2015
Subject: Re: Why UHMWPE is so AWEsome

Group: AirborneWindEnergy Message: 17137 From: benhaiemp Date: 3/2/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17138 From: Rod Read Date: 3/3/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17139 From: dave santos Date: 3/3/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17140 From: Rod Read Date: 3/3/2015
Subject: Re: Torque

Group: AirborneWindEnergy Message: 17141 From: benhaiemp Date: 3/3/2015
Subject: Lift during loop

Group: AirborneWindEnergy Message: 17142 From: dave santos Date: 3/3/2015
Subject: Re: Torque



Group: AirborneWindEnergy Message: 17093 From: dave santos Date: 3/1/2015
Subject: Re: Torque
The General Electric fabric-covered HAWT blades are not suited to fly, but to reduce the capital cost of wind towers. They do not constitute a radical AWE solution to square-cube law, since they are based on massive rigid spar cantilevers (they do show that fabric can endure outdoor conditions for many years). Even fabric covered airplanes are not a valid example of a major scaling solution (like all-soft-kite construction).

Soft kites already hold the world record for the largest wings ever flown (Osborne's
Group: AirborneWindEnergy Message: 17094 From: dave santos Date: 3/1/2015
Subject: Re: Hello i am student from korea and i wanna know if i can get a ch
Dear Yeji Kim,

It would be a pleasure to help your Airborne Wind Energy study project. Feel free to ask any questions and we will do our best to answer.

Its a very exciting early stage in AWE, and you and your classmates have a fine opportunity to advance the state-of-the-art by reviewing the research so far, and adding your own discoveries.

Cheers,

dave santos 
kPower




On Sunday, March 1, 2015 8:04 AM, "yeji kim yeahji1@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy-noreply@yahoogroups.com
Group: AirborneWindEnergy Message: 17095 From: joe_f_90032 Date: 3/1/2015
Subject: Re: Torque
Preamble:  Square-cube law - Wikipedia, the free encyclopedia

 

Then consider seeing the rung compression beams in the torque-ladder as having volume.

Group: AirborneWindEnergy Message: 17096 From: Rod Read Date: 3/1/2015
Subject: Re: Regenerating Kite Structure

So,  by tilted upwind Dave S you mean.. Like a tail? From the trailing edge going down to ground downwind?
Otherwise please annotate or post a picture example. We shouldn't have to suffer a language battle. This is a communication age. You have the skill.

In plane control lines are not exotic true.
Yes they can run through large sails.

For stability in real wind fields... Large sails on the scale you're looking for need to be broken into kixels and networks of fractal divided topologies. This way they will react faster to disturbance.

A Daisy has a spinning network set over a lift line.. Preferably held aloft on a network. That's redundancy, fast acting change and inherent generation in soft architecture. It's fast load motion too. Sounds great. Lets get lifting them in strings.
Can they be pruned for recycling at the top of their tether? Maybe. Probably.
Can new blade kites set on old rings?
Maybe. Probably.

I'm likely about to reuse the old Daisy set with the new for stability improvement.

I best now rescind my claim of the Google x or Makani crew being Grade A dicks.

Ps. In my recent test, think there was a coms issue between my phone app and bike wheel regeneration setting level... That level should have kicked out way more power at that speed.
It's always a comms and cable link problem.

Group: AirborneWindEnergy Message: 17097 From: benhaiemp Date: 3/1/2015
Subject: Re: Fabric Scaling?

DaveS,


Please can you indicate at what maximal area do you estimate scalability of a (manageable) ram-air wing as  New Payload Record for Largest Autonomously Guided Ram-Air Parachute - Airborne Systems - Military Suppliers - Copybook (10,400 ft² or 966 m²) ? Thanks.

 PierreB
Group: AirborneWindEnergy Message: 17098 From: Rod Read Date: 3/1/2015
Subject: Re: Torque

Torque drive believers are invited to try to beat the 200ft torque challenge, and experience firsthand just how desperately limited the method is; never mind engineering calculations based on Galileo's Scaling Law, and  all the other defects (low-rpm with excess aerodrag, cost, and risk).

I'm going to say you're right. Never mind the poor engineering guesses, irrelevant science, and wrong statements.

Low rpm as compared to your looping parafoil torque device? The pricey one kite with a bunch of excessively spongy long long lines and no multiple line backup... Right?

Group: AirborneWindEnergy Message: 17099 From: dave santos Date: 3/1/2015
Subject: Re: Fabric Scaling?
On Sunday, March 1, 2015 12:47 PM, "pierre.benhaiem@orange.fr [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17100 From: dave santos Date: 3/1/2015
Subject: Passive Barometric Kite Killers
 A megascale soft kite will require layers of safety to operate permanently over populations. The greatest danger would be concentrated drag-line forces causing mass destruction. A reliable passive fail-soft mechanism is a critical requirement.

A novel form of kite killer would be barometrically activated line releases that hold securely at high altitude but passively release at low latitudes, to depower the lanyard-retained kite structure. Such a device could be as simple as an air bladder that expands to pull a pin or drive a line-cutter. It could passively arm by ground-anchored taglines that pull out arming pins as the kite structure reaches a minimum altitude. This method would be minimally burdensome for lattices that fly continuously by reverse-pumping in calm.

CC+ Open-AWE IP-Pool
Group: AirborneWindEnergy Message: 17101 From: dave santos Date: 3/1/2015
Subject: Re: Torque
Note that kPower's looping parafoils naturally create high-speed load motion by a "bow-string geometry" * (main anchor, PTO, and looper forming a tri-tether variable mechanical advantage transmission).

A favored high rpm mechanism at the generator is a belt wound around around a small gen shaft (with rachet and elastic-retract). Typical pumping-stroke rpms are many times higher than a torque ladder can possibly reach. Added flywheel mass can smooth the generator output. A gear train or excessively large generator is avoided.

CC+ Open-AWE IP-Pool
-------------
* Imagine an arrow replaced by a pull-string added to a bow-string, for high-speed motion. A small slower spreading motion of the bow-string ends results in ultra-fast motion at the pull-string.
Group: AirborneWindEnergy Message: 17102 From: dave santos Date: 3/1/2015
Subject: Re: Regenerating Kite Structure
-tether POV relative to flier on the ground-

WIND = /\
negative lift / \ positive lift
/ \

"tilted downwind" / \ "tilted upwind"
/ \
------------------ ground -----------------------
Group: AirborneWindEnergy Message: 17103 From: dave santos Date: 3/1/2015
Subject: Re: Regenerating Kite Structure
Having problems with old-scholl ascii art in this crappy mailer- Does this work for others?
Group: AirborneWindEnergy Message: 17104 From: snapscan_snapscan Date: 3/1/2015
Subject: Re: Torque
Thank you Dave, 

I found&read the chapter "The mysteries of shear and torsion".

Fun fact: There are 0 shear or torsion forces in the spaced ladder. It's all just tension and compression. This is the beauty of this method: It is a method to TRANSFER torque by using nothing but tension and compression. Hence Gordon's critique is not applicable.

Also, Gordon concludes the chapter with "Unlike engineers Nature has little interest in rotary motion [...] she has never bothered to invent the wheel"

Well, I am an engineer - hence Gordon correctly predicts my interest in rotary motion. I am also very grateful for the invention of the wheel.

Gordon is right in assuming that something is a sound concept if nature is using it - otherwise it would have gotten rid of it.

However! It is a fallacy to conclude that the opposite holds true too. Humans have invented the wheel and the torque to power it - both concepts are pretty cool - even if nature has not come up with them. You would have had a point if nature used torque in the past and abandoned it (maybe we will find out that dinosaurs had wheels!).

Summary:

I honestly appreciate your critique of the spaced ladder for if if would hold up I could save time and money. As for now both of your points seem however not applicable.

1. You can scale a spaced ladder in one dimension without running into the square-cube law. Will it be an issue when trying to scale up the power? Maybe.

2. It is cool that Gordon and mother nature do not like torque - because the spaced ladder does not use it.

In another post you stated:

"No one can effectively get to 200ft with AWES torque-ladders" Hence let me conclude with:

Challenge accepted! (having grown up in old Europe where we use the metric system I would like to slightly lower this to 50m if you do not mind. Until Rod reaches that height I will not post anything on this topic.

If Rod (or somebody else) should make it all I want to see is a post from you saying:"Damn, Rod maybe you are up to something"

Deal?
/cb



Group: AirborneWindEnergy Message: 17105 From: dave santos Date: 3/1/2015
Subject: Re: Torque
There is no escaping Galileo and Gordon by means of torque ladders, in my opinion.

There is in fact bulk torsion and shear forces in a torque-ladder, if it is fairly treated a single geometric object, not as separate parts. The structure as whole clearly experiences torsion based on applied torque, as formally defined-


The foundational condition of "pure shear" is characterized by "a body [that] is elongated in one direction while being shortened perpendicularly"; in this case each helical torque-ladder line axis elongates as each perpendicular spar axis tends to shorten. There are also secondary local shears where lines cross spar ends, as the ladder undergoes high "density-of-states" deformations-


If Galileo was wrong about rigid structure like torque-ladder spars, and Gordon was wrong about torsion and shear limits to a torque-ladder (not a case of "poison"), then we should expect to find successful torque ladders in nature or technology. Let someone present such a similarity case, or attempt a scaled-up torque ladder AWES. The ladder does have a modest scaling edge, being a quasi-2D ribbon, but its not enough; its essential spars are too similar to Galileo's elephant bones.
 


On Sunday, March 1, 2015 7:06 PM, "snapscan_snapscan@yahoo.de [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17106 From: dave santos Date: 3/1/2015
Subject: Re: Torque
AWES torque-drive claims stand or fall on comparative testing and simulation against standard mechanical transmission options like rope-driving. Here is the classic baseline reference for rope-driving, which will be new to some, but was extensively reviewed before on the Forum. The astounding rope-driving performance of past centuries has been greatly multiplied by modern super-fibers-

 


On Sunday, March 1, 2015 10:29 PM, dave santos <santos137@yahoo.com
Group: AirborneWindEnergy Message: 17107 From: Rod Read Date: 3/2/2015
Subject: Re: Fabric Scaling?

A single 10km2 kite sounds nightmarish.
Baggsie I'm not being the pilot in command. With the current weather here I wouldn't be able to see the whole kite for a start.
Next problem is our gusty, rolling, swinging wind.
Having 1000 kites totaling 10km2 fly autonomously together sounds loads easier.

Group: AirborneWindEnergy Message: 17108 From: Rod Read Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers
If you use multiple unit kites on a net instead of 1 sheet...
Net hauling gear set on multiple anchor site locations.
If each one is capable of hauling in more than their normal share.
Breakaway is mitigated and controlled.

I'd hazard a guess that radio release systems will be more reliable and lighter than barometric.
Thus allowing you to remove patches of net from the sky at a time.

A net above a populous to protect from fall.
It's going to be easier to get permission to put a net over the city than flying a similarly sized kite over a city.
If you've watched the film / documentary  "Man on Wire" You'll realise it's possible to tie two tall buildings together to steady them...
but the law and society may take a bit of time to catch onto the practical uses of the idea.

Rod Read

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

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17109 From: Pierre BENHAIEM Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers

Why not an airborned "net above a populous to protect from fall." ?

 

PierreB

 

 

 

 
Group: AirborneWindEnergy Message: 17110 From: Pierre BENHAIEM Date: 3/2/2015
Subject: Re: Fabric Scaling?

10 km² : 5-15 GW range. An AWES plant can be attractive from 500 MW range, which is that of coal plant range. Does not look possible above a town, even with an (why not airborne !) net of protection. But above great farms, seas, deserts where AWES as secondary use can provide shade (see JoeF'topic about shade)...

 

PierreB

 

 

 

 
Group: AirborneWindEnergy Message: 17111 From: Rod Read Date: 3/2/2015
Subject: Bowstring geometry
It has been claimed recently that ...

looping parafoils naturally create high-speed load motion by a "bow-string geometry" * (main anchor, PTO, and looper forming a tri-tether variable mechanical advantage transmission
A favored high rpm mechanism at the generator is a belt wound around around a small gen shaft (with rachet and elastic-retract). Typical pumping-stroke rpms are many times higher than a torque ladder can possibly reach. Added flywheel mass can smooth the generator output. A gear train or excessively large generator is avoided.
* Imagine an arrow replaced by a pull-string added to a bow-string, for high-speed motion. A small slower spreading motion of the bow-string ends results in ultra-fast motion at the pull-string.

OK so I imagine this retracted rope arrow is "fired" by releasing the ratchet hold on the elastic rewound gen shaft when the looping kite is at 7 o clock... Is that right?
How is the ratchet released?
To get the "rope arrow" to retract in time do you keep the gen take off shaft spinning for full phase reversal or retract it half phase reversal?

I still struggle to see this dynamic as anything like bow string.

Please if you understand or propose this as a useful AWES consider trying even the smallest of open source graphics software.
This will help to efficiently communicate the principle... maybe Inkscape or Anvil for overlaying on existing videos.

 
Rod Read

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

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17112 From: Rod Read Date: 3/2/2015
Subject: Re: Torque
The rungs of a torque transmitting spaced ladder on a lift line are not all purely in compression.
Most notably the top rung also has a bending moment induced in it's centre where it is retarded from travelling down along the lift line vector.

Also if this holds true....
The foundational condition of "pure shear" is characterized by "a body [that] is elongated in one direction while being shortened perpendicularly";
It certainly does not describe the motion inherent of a torque transmitting spaced ladder.
The ladder widens as it is stretched and will only narrow on the perpendicular axis between rungs if it is allowed to shrink in length.

The statement ... in this case each helical torque-ladder line axis elongates as each perpendicular spar axis tends to shorten.
is completely the wrong way round.

Rod Read

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

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17113 From: Rod Read Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers
Airborne would suggest it could fall when the means of using air for support fails.
A propped up net is really very reliable... Especially if the buildings exist at height already.

Rod Read

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

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17114 From: Rod Read Date: 3/2/2015
Subject: Re: Fabric Scaling?
How to derive the best arch to put over a population...
https://vimeo.com/120671854

Rod Read

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

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17115 From: joe_f_90032 Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers

The intro post in this topic had a phrase: 

"an air bladder that expands to pull a pin or drive a line-cutter".

I suggest that the "expands" does not occur when the device goes to lower altitude, but rather an air bladder contracts as the bladder goes to lower altitude.  Hence, having instead a contracting chamber to pull a pin or drive a line cutter could be the passive actuator.   Do we affirm the suggested correction?  CC+ Open-AWE IP-Pool

JoeF
Group: AirborneWindEnergy Message: 17116 From: joe_f_90032 Date: 3/2/2015
Subject: Integrated Power Technology Corporation™

Rod, in another topic thread, asked : have we listed

 http://www.intpowertechcorp.com/

  http://www.intpowertechcorp.com/ here or on http://energykitesystems.net/

 yet?


No. Except your intro above. So, this topic thread.


Integrated Power Technology Corporation™ Their tech in first blush to me feels nearly as a hydro version of IFO of Dobos style; the tech seems to be an untethered system. This topic thread invites discussion of IPTC's tech with RAD in focus. What first comes to mind for me is using kite systems instead of the close-coupled low-altitude sails that IPTC offers. We actually have such as Jon Chul Kim as a strong contender for water hull based kite systems doing much of what IPTC suggest. IPTC has a focus on their unmanned control systems' patent applications ... software. The mechanical concepts have been in public domain up to generation electricity and making chemicals at sea by use of sail and kited sail means. IPTC might arrive to the forum to point out any specific novelty involved.


KitVes also contributes to the water world touched by IPTC.

http://www.energykitesystems.net/0/KitVes/

~ JoeF

Group: AirborneWindEnergy Message: 17117 From: benhaiemp Date: 3/2/2015
Subject: Re: Torque

CB wrote : "There are 0 shear or torsion forces in the spaced ladder. It's all just tension and compression."

So is torque-ladder + tension by kite (or other) = a novel variant of

Tensegrity - Wikipedia, the free encyclopedia

?


PierreB 
Group: AirborneWindEnergy Message: 17118 From: benhaiemp Date: 3/2/2015
Subject: Re: Torque

So is torque-ladder + tension and torque by kite (or other) = a novel variant of

Tensegrity - Wikipedia, the free encyclopedia?

 
Group: AirborneWindEnergy Message: 17119 From: joe_f_90032 Date: 3/2/2015
Subject: Re: Torque
Group: AirborneWindEnergy Message: 17120 From: christopher carlin Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers
Same mechanism as automatic releases for life rafts. 

Regards,

Chris
On 1 Mar 2015, at 22:58, dave santos santos137@yahoo.com [AirborneWindEnergy] <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17121 From: dave santos Date: 3/2/2015
Subject: Re: Passive Barometric Kite Killers
Thanks JoeF for correcting inflation to deflation, and ChrisC for the life-raft similarity case. In principle a directly self-actuated mechanism can be more reliable and cheaper than more complex systems with aging radio links, batteries, command requirement, etc. The place for active control might be to deactivate the device network for a planned landing. Note that a full-kill of separable parts was not proposed, only a minimal "spoiling" of flight trim to kill power.

The dream is a vast perpetual airborne lattice*, able to furl its sail area ahead of storms and reverse-pump and/or slow-descend in calm (with spot hotswapping of blown kixels aloft, as opposed to scheduled replacement of all kixels on the ground). Then the passive kite killer network is reserved for a rare worst-case loss-of-control (like a sudden rogue gravity wave breaking on the lattice).

------------------
* That is not socially oppressive.


On Monday, March 2, 2015 8:52 AM, "christopher carlin christopher.m.carlin@btinternet.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17122 From: dave santos Date: 3/2/2015
Subject: Re: Bowstring geometry
In this case the PTO "arrow line" is not "fired" all at once, but pumps the flywheel/generator shaft in a smoothed sinusoidal cycle (rounded saw-tooth waveform).

The mechanical advantage of the pulsing bow-line is the same as bow-geometry, but without the sudden violent release, just a smooth high load-velocity phase. A sprag or rachet on the gen shaft and elastic return for the PTO line completes the device.


On Monday, March 2, 2015 5:08 AM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17123 From: dave santos Date: 3/2/2015
Subject: Re: Fabric Scaling?
Yes, giant wings in the sky could be a nightmare, but those of us who grew up preparing for nuclear war are hard to scare, and we know worse scenarios than wind-powered sky cities
Group: AirborneWindEnergy Message: 17124 From: dave santos Date: 3/2/2015
Subject: Re: [AWES] Integrated Power Technology Corporation™
Lets also recall DaveL's white-paper to crack hydrogen on a global scale by towing water-turbine ships with kites, which is a more advanced platform than IPTC's.


On Monday, March 2, 2015 7:37 AM, "joefaust333@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17125 From: dave santos Date: 3/2/2015
Subject: Re: Torque
How can the ladder possibly "widen" as its spars are compressed? Its only ever as wide as its spars. Yes, the overall twisted ladder will constantly shorten and lengthen by normal chaotic dynamics, but the string length stress cycling is fairly independent of overall length.

Another way to see ladder flaws is to compare with the same amount of string used as a rope-drive loop. The sticks are then seen as an avoidable source of diminished performance and added expense, danger, mass-aloft, excess-drag, etc.


On Monday, March 2, 2015 8:35 AM, "joefaust333@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17126 From: dave santos Date: 3/2/2015
Subject: Why UHMWPE is so AWEsome
The carbon backbone of the UHMWPE molcule is a zig-zag line of carbon atoms just like a path on a graphene lattice, so its the closest thing to carbon nanotubes, but already a standard COTS polymer. The zig-zag bonding creates a high quality spring that is stretched into an ultra stiff line with increased thermodynamic order. Its an entropy-order storage capacitor.

The carbon atoms are packed in with hydrogen atoms; the low final density is due to hydrogen and carbon being only 1 and 6, respectively, on the periodic table, so UHMWPE floats on water (whose oxygen is 8 on the Table). Low density and high stiffness is the secret of the super high internal speed of sound of UHMWPE (~40km sec).

The sonic limit correlates with high Debye specific heat (
Group: AirborneWindEnergy Message: 17127 From: snapscan_snapscan Date: 3/2/2015
Subject: Re: Torque
Yes, I was actually looking at different Tensegrity structures when coming up with the center tension line. Not a single element in a torque-ladder experiences any torsion or shear forces.

 /cb
Group: AirborneWindEnergy Message: 17128 From: Rod Read Date: 3/2/2015
Subject: Re: Bowstring geometry

Is the ground anchor considered as 1 end of this bow line?

Group: AirborneWindEnergy Message: 17129 From: dave santos Date: 3/2/2015
Subject: Re: Torque
One must first accept as applicable the formal definitions of "torsion and "pure shear" to willingly concede torque-ladder experiences torsion and shear forces as emergent formal properties of the elements as a whole.

One must also look closely at the line-spar junctions to see critical local shear stresses promoted where tensed lines cross narrow sticks perpendicularly, with high side-loading shear on the line. Therefore added stress-relieving mass is wanted to cushion lines from prematurely failing from shear at these joints. Nor do ladder joints line up a single angle. A crude torque ladder will flex lines at spar joints in shear-stress cycles (unless a pivot is provided at every joint, tending toward further excess complexity and mass).

Gordon and Galileo's curse is strongest for design-imposed compression loads, not pure tensile-structure design. Compression is easily converted to shear stress by rotational eigenstates common in real-world chaos. Too much extra mass is required for an equivalent reliability factor or loading for scaled-up spars. This predicts the torque ladder cannot compete with simple rope-driving in any critical factor (safety, cost, performance). The 200ft torque-ladder challenge is intended as a Pyrrhic Victory only, where the cost and comedy would underscore the inability to scale to 2000ft, where the action is.

Anyone who tries to do a large AWES torque-ladder is a hero for testing Galilean Law, as long as there are influential non-believers (v. believers) in the theory and lack of similarity cases.


cb wrote: "Not a single element in a torque-ladder experiences any torsion or shear forces."


On Monday, March 2, 2015 12:34 PM, "snapscan_snapscan@yahoo.de [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17130 From: Rod Read Date: 3/2/2015
Subject: Re: Torque

How can the ladder possibly "widen" as its spars are compressed?
Well I certainly haven't suggested that. And it's a ridiculous question. Posed by someone avoiding straight sense.
The point I made now reiterated for those hard of comprehension...
When Two rungs of a rope ladder are being twisted against each other around a central line they tend toward each other. When viewed Axially in this twisted state the side lines are seen to move closer (at their centres) toward the central line (axis of rotation).
Thus the ladder shortens and thins simultaneously.

Conversely untwisting the rungs allows them to extend along their axis.

In the case of the recently demonstrated ladder the inter rung axial twist is 45deg 60cm spacings 60cm wide (long tube) rungs.

Limiting the max twist is important for good torque transfer.

Group: AirborneWindEnergy Message: 17131 From: dave santos Date: 3/2/2015
Subject: Re: Bowstring geometry
The ground is one end of the "bow", and the kite is the other, and the mainline is the "bowstring". The "bowstring" pulls fast motion on the orthogonal PTO (like an archer's arm worked in reverse, but no "arrow" drawn).


On Monday, March 2, 2015 12:46 PM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17132 From: Rod Read Date: 3/2/2015
Subject: Re: Bowstring geometry

The ground doesn't move.

Your pto rope is going to have some "unscalable" shear stress of doom points around the knot on the "bowstring"

Group: AirborneWindEnergy Message: 17133 From: dave santos Date: 3/2/2015
Subject: Re: Torque
The "strait sense"" is this: the spar remains the defining maximum-width location (which does shrink slightly, in accord with pure-shear), and the lines twisting towards each other can be seen as incipient necking*, and easily leads to "bow-tie (twist) failure" in the flat ribbon geometry.




On Monday, March 2, 2015 2:17 PM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17134 From: dave santos Date: 3/2/2015
Subject: Re: Torque
Correction: "straight sense" was the intended spelling.


On Monday, March 2, 2015 2:29 PM, dave santos <santos137@yahoo.com
Group: AirborneWindEnergy Message: 17135 From: dave santos Date: 3/2/2015
Subject: Re: Bowstring geometry
Under Galilean Relativity the ground does move in relation to the kite, and one is free to choose a POV. The bowline is a good similarity case, if one can see motion like Galileo. Einstein rightly reckoned Galileo as the "father of modern science" for this sort of insight, which is still unacceptable to many.

Its true that knots and joints do require special care and extra mass to reduce the stress-concentration, but in the looping-foil case such critical details are number-minimized and therefore easily and cheaply mitigated, but in the ladder case, multiplied, and proportionally more costly to correct.

No AWES scheme is perfect, but KIS design tends strongly to win in engineering design, so my bet is on KIS, even if 17th century physics explanations are rather advanced.


On Monday, March 2, 2015 2:33 PM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17136 From: joe_f_90032 Date: 3/2/2015
Subject: Re: Why UHMWPE is so AWEsome
Ultra-high-molecular-weight polyethylene - Wikipedia, the free encyclopedia

 
Group: AirborneWindEnergy Message: 17137 From: benhaiemp Date: 3/2/2015
Subject: Re: Torque

So the kite both tows _ providing tension in torque-ladder _ and rotates _ providing compression ,spars tending to be moved closer.

Two ways for torque :

ladder to falco power test

 looping foil, pumping air

Torque-ladder allows continuous power, avoiding expensive devices like flywheel or hydraulic accumulator. But launching looks difficult . A mean to launch ropes in first and spars in second could be studied. And if spars can be "depowered" in case of storm ropes will twist without acting the generator...


PierreB
Group: AirborneWindEnergy Message: 17138 From: Rod Read Date: 3/3/2015
Subject: Re: Torque
Mechanical decoupling of the ladder drive from the PTO could be as simple as an inline clutch.
I think what's more pressing is understanding correctly the dynamic ratios of lift needed per power & length.
More likely to be lift needed per torque per spar gap dynamic. and at what line stability or straightness.


Rod Read

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

07899057227
01851 870878
Group: AirborneWindEnergy Message: 17139 From: dave santos Date: 3/3/2015
Subject: Re: Torque
Note that short-cycle energy storage is cheap, because a momentary amount of storage capacity does the job (including elastic potential-energy stored briefly in an AWES lattice). A utility scale kite farm, with many WECS sub-units pumping in-phase, will not require any short-cycle storage.

These are just more reasons to avoid the critical problem of torque drives (excess mass-aloft) with pumping-drives. Don't like pumping? Classic rope-driving is continuous, with two lines like a ladder; but without added spars. Torque-ladders are not even the preferred short-distance high-mass torque-engineering design, or vehicles would use them instead of universally adopted torque-tubes. Airplanes, however, abandoned torque tube aileron control actuation in favor of lighter cheaper cables a lifetime ago.

The original 2006 KiteLab prediction: "Best AWE physics wins". Has anyone yet offered a successful similarity-case for long range torque-drives or large-scale torque-ladder driving? No such similarity-cases are predicted by Gordonian and Galilean physics critique. 




On Tuesday, March 3, 2015 1:36 AM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 17140 From: Rod Read Date: 3/3/2015
Subject: Re: Torque

Dave S,
I'm very happy for you to motivate and organise the worlds political will into making the giant kite you desire.
Heck I may even get back into drawing some massive collective action kite devices soon. I have some ideas burning away.

In the meantime...
Torque gets the job done unit by unit.

I'll keep working on spinny units, lifters, meshes etc without giving up on rope driving.

The spaced ladder torque method certainly is not
high-mass torque-engineering

A similarity case search is hardly a physics approach.

Group: AirborneWindEnergy Message: 17141 From: benhaiemp Date: 3/3/2015
Subject: Lift during loop

Lift is Joe's key word .


During my tests of loops with a ram-air two lines, I must pull one line to make lift in each loop, allowing the kite keeping its global altitude (the same for Makani with other means of control). In case of no control it is like  Rotating kite  where you can see the loop lossing slowly average altitude. Some ideas to keep altitude?



For Daisy (excepted by pilot kite) there is not enough lift: perhaps some lift can be obtained by cyclical action on the three rotating wings , a little like variable picth for helicopeters. Some ideas to increase the angle of flight (before pilot kite)?

wind turbine with no tower

  


PierreB
Group: AirborneWindEnergy Message: 17142 From: dave santos Date: 3/3/2015
Subject: Re: Torque
Its absurd to claim I "motivate and organise the world's political will". Nor do I desire a "giant kite" as such (its a forced engineering response to perceived crisis*). My philosophy is to promote comparative flight testing of all ideas, and let results decide winners and losers.

My concern is for anyone who over-embraces torque into a losing down-select, if Gordon and Galileo really are right. If torsion really is AWES "poison", better that you find out soon, so you can move on to the better solutions faster.
----------------
* We need more renewable flight options than dependence on kites.


On Tuesday, March 3, 2015 1:43 PM, "Rod Read rod.read@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com