Messages in AirborneWindEnergy group.                           AWES14590to14639 Page 187 of 440.

Group: AirborneWindEnergy Message: 14590 From: dave santos Date: 9/20/2014
Subject: Why level HTA flight inherently requires power (viscous drag, lift-i

Group: AirborneWindEnergy Message: 14591 From: Pierre BENHAIEM Date: 9/20/2014
Subject: Re: Progress in AWES R&D (utility-scale)

Group: AirborneWindEnergy Message: 14592 From: Pierre BENHAIEM Date: 9/20/2014
Subject: Re: Progress in AWES R&D (utility-scale)

Group: AirborneWindEnergy Message: 14593 From: dave santos Date: 9/20/2014
Subject: Minimum Drag ("aviation power curve")

Group: AirborneWindEnergy Message: 14594 From: dave santos Date: 9/20/2014
Subject: Re: Who is an AWE Engineer? (The lies of Dave S.)

Group: AirborneWindEnergy Message: 14595 From: joe_f_90032 Date: 9/20/2014
Subject: Re: Multi-rotor kite-lifted "Coaxial multi-turbine generator" by Ha

Group: AirborneWindEnergy Message: 14596 From: dave santos Date: 9/20/2014
Subject: Re: Multi-rotor kite-lifted "Coaxial multi-turbine generator" by Ha

Group: AirborneWindEnergy Message: 14597 From: dave santos Date: 9/21/2014
Subject: KiteMill Rising

Group: AirborneWindEnergy Message: 14598 From: dave santos Date: 9/21/2014
Subject: Shipping News' ongoing AWE drum-beat

Group: AirborneWindEnergy Message: 14599 From: dave santos Date: 9/21/2014
Subject: MIT data-mines JoeF for Makani Clues

Group: AirborneWindEnergy Message: 14600 From: dave santos Date: 9/21/2014
Subject: IFO Mountain and Cloud DSing Opportunities

Group: AirborneWindEnergy Message: 14601 From: dave santos Date: 9/21/2014
Subject: India's Kite Energy magazine (announcement)

Group: AirborneWindEnergy Message: 14602 From: dougselsam Date: 9/22/2014
Subject: Re: Who is an AWE Engineer? (The lies of Dave S.)

Group: AirborneWindEnergy Message: 14603 From: dougselsam Date: 9/22/2014
Subject: Re: Engineering Credentials?

Group: AirborneWindEnergy Message: 14604 From: dougselsam Date: 9/22/2014
Subject: Re: Progress in AWES R&D (utility-scale)

Group: AirborneWindEnergy Message: 14605 From: dougselsam Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)

Group: AirborneWindEnergy Message: 14606 From: dave santos Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)

Group: AirborneWindEnergy Message: 14607 From: joe_f_90032 Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)

Group: AirborneWindEnergy Message: 14608 From: dave santos Date: 9/22/2014
Subject: Re: Engineering Credentials?

Group: AirborneWindEnergy Message: 14609 From: dave santos Date: 9/22/2014
Subject: Re: Multi-rotor kite-lifted "Coaxial multi-turbine generator" by Ha

Group: AirborneWindEnergy Message: 14610 From: dougselsam Date: 9/22/2014
Subject: Re: Engineering Credentials?

Group: AirborneWindEnergy Message: 14611 From: dougselsam Date: 9/22/2014
Subject: Re: Engineering Credentials? Technician...

Group: AirborneWindEnergy Message: 14612 From: dave santos Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)

Group: AirborneWindEnergy Message: 14613 From: Baptiste Labat Date: 9/22/2014
Subject: Reconciliations

Group: AirborneWindEnergy Message: 14614 From: dougselsam Date: 9/22/2014
Subject: Re: Reconciliations

Group: AirborneWindEnergy Message: 14615 From: dougselsam Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)

Group: AirborneWindEnergy Message: 14616 From: dave santos Date: 9/22/2014
Subject: Re: Engineering Credentials?

Group: AirborneWindEnergy Message: 14617 From: Pierre BENHAIEM Date: 9/22/2014
Subject: Re: Progress in AWES R&D (utility-scale)

Group: AirborneWindEnergy Message: 14618 From: dougselsam Date: 9/22/2014
Subject: Re: Engineering Credentials?

Group: AirborneWindEnergy Message: 14619 From: Joe Faust Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)

Group: AirborneWindEnergy Message: 14620 From: dougselsam Date: 9/22/2014
Subject: Re: Progress in AWES R&D (utility-scale)

Group: AirborneWindEnergy Message: 14621 From: dave santos Date: 9/22/2014
Subject: Re: Engineering Credentials? Technician...

Group: AirborneWindEnergy Message: 14622 From: dave santos Date: 9/22/2014
Subject: Re: Engineering Credentials?

Group: AirborneWindEnergy Message: 14623 From: Joe Faust Date: 9/22/2014
Subject: Re: Progress in AWES R&D (utility-scale)

Group: AirborneWindEnergy Message: 14624 From: dougselsam Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)

Group: AirborneWindEnergy Message: 14625 From: benhaiemp Date: 9/22/2014
Subject: Criteria towards an AWE standard (for electricity production)

Group: AirborneWindEnergy Message: 14626 From: dave santos Date: 9/22/2014
Subject: Re: Reconciliations

Group: AirborneWindEnergy Message: 14627 From: dave santos Date: 9/22/2014
Subject: Micro-Disturbances in AWES Winds

Group: AirborneWindEnergy Message: 14628 From: dave santos Date: 9/22/2014
Subject: Re: Who is an AWE Engineer? (The lies of Dave S.)

Group: AirborneWindEnergy Message: 14629 From: dave santos Date: 9/22/2014
Subject: DIY Drone AWE discussion (past years)

Group: AirborneWindEnergy Message: 14630 From: dave santos Date: 9/22/2014
Subject: Re: Reconciliations

Group: AirborneWindEnergy Message: 14631 From: Baptiste Labat Date: 9/23/2014
Subject: Re: Micro-Disturbances in AWES Winds

Group: AirborneWindEnergy Message: 14632 From: Rod Read Date: 9/23/2014
Subject: Re: AWES Torque Transfer via Tensegrity Tensairity Towers (TTviaTTT)

Group: AirborneWindEnergy Message: 14633 From: Rod Read Date: 9/23/2014
Subject: Re: Criteria towards an AWE standard (for electricity production)

Group: AirborneWindEnergy Message: 14634 From: Rod Read Date: 9/23/2014
Subject: Re: Reconciliations

Group: AirborneWindEnergy Message: 14635 From: Rod Read Date: 9/23/2014
Subject: Re: Micro-Disturbances in AWES Winds

Group: AirborneWindEnergy Message: 14636 From: Rod Read Date: 9/23/2014
Subject: Does this clutch exist yet

Group: AirborneWindEnergy Message: 14637 From: dougselsam Date: 9/23/2014
Subject: Re: Reconciliations

Group: AirborneWindEnergy Message: 14638 From: Rod Read Date: 9/23/2014
Subject: Smart atom spaxels

Group: AirborneWindEnergy Message: 14639 From: dougselsam Date: 9/23/2014
Subject: Re: Who is an AWE Engineer? (The lies of Dave S.)




Group: AirborneWindEnergy Message: 14590 From: dave santos Date: 9/20/2014
Subject: Why level HTA flight inherently requires power (viscous drag, lift-i
Various kinds of drag are unavoidable for HTA level flight, like Form-Drag (no such thing as an infinitely thin wing). Lets just consider one kind in detail, Viscous Drag, since just one drag effect is enough to invalidate the "zero power" HTA level flight fallacy-

-Air is a classic Newtonian Fluid, with Viscous Drag as a natural effect of wings working in Air.

-If Air were a Non-Newtonian SuperFluid, there would be "zero" Viscous Drag, but its not.

-Viscous Drag of HTA flight must be overcome by power to sustain level flight.

-The albatross does not fly by "zero-power", but overcomes Viscous Drag (and other drag factors) by DSing.

-Powered aircraft offset Viscous Drag by applied-power for level flight.

-Kites overcome Viscous Drag by the thrust of its tether-anchor in wind, for level flight.

-A glider overcomes Viscous Drag by tapping kinetic energy of rising air, for level flight.

-Even "infinite-wingspan" model assumptions must account for (or neglect) Viscous Drag.

-The Standard Drag Curve is telling. The Viscous Drag coefficient actually grows if one vainly seeks to achieve "zero power" HTA level flight by designing ever larger slower wings.


Other kinds of drag are worth reviewing, if there is any doubt about the "zero power" flight fallacy-






Group: AirborneWindEnergy Message: 14591 From: Pierre BENHAIEM Date: 9/20/2014
Subject: Re: Progress in AWES R&D (utility-scale)

DaveS,

Concerning "FAA-driven kitefarm window (600M high x 1200M wide reference-unit)" we had some discussion with some discord not about theoretical possibilities but, for me, about efficiency on method involved. So the number you gave (a fraction of 60 MW, 20 MW (?) please correct me if it is not that) seems correct. The number I gave (1/520 of it ) was about what I saw on the method involved and by taking account (rightly or wrongly) of a schema of both not directional HAWT and WECS as looping-units, since I do not saw (rightly or wrongly) arch as (easily) directional.

So I propose to take again numbers, then refining them, then going to methods. For it take us for example Vestas V164 , swept area 21,124 square metres, diameter of rotor 164 metres , output 8 MW, wind speed 11 m/s , total height 220 metres.

Note for conventional wind turbines 11 m/s is often the value of reference. So the altitude of AWES being from 50 metres to 600 metres instead of from 56 metres to 220 metres, we can push to something like 13 m/s to make equal things. So the 8 MW/21,124 m² become 13 MW.  Swept area is a little reduced: 550 m x 1150 m = 632,500 m². Power in HAWT features raised in 13 m/s wind speed:  389 MW. An AWES being able to take 1/10 ( 39 MW) of it would be more than excellent.This value is not too far the value you provided, the difference here being wind speed reference. 

 

PierreB

 

Group: AirborneWindEnergy Message: 14592 From: Pierre BENHAIEM Date: 9/20/2014
Subject: Re: Progress in AWES R&D (utility-scale)

"since I do not saw" corrected in "since I did not see"

 

PierreB

 




Group: AirborneWindEnergy Message: 14593 From: dave santos Date: 9/20/2014
Subject: Minimum Drag ("aviation power curve")
Fact: Drag is a fundamental property of aviation, and requires power to overcome.

Third-party validation for inherent minimum drag of flight (v "zero power" flight fallacy)




Group: AirborneWindEnergy Message: 14594 From: dave santos Date: 9/20/2014
Subject: Re: Who is an AWE Engineer? (The lies of Dave S.)

Doug, 

I can't find the "lie" quote (below) that you attribute to me, but I do stand on 10W as an honest "first approximation" (under standard definition). 3.8W is the second approximation, and its pretty solid as such. Give me time now, if your sincere challenge is to find engineers who disagree with your flight phyics conclusions (I am very busy, and recruiting the engineers requires their lag time too)

The quotes of yoursI referenced also got changed. You did claim "zero power" several times, as I quoted correctly (not "trending towards zero", which is not right either (see viscous drag note).


Google Search- "No results found for "It takes 10 Watts to remain aloft - final answer"."


On Saturday, September 20, 2014 10:16 AM, dave santos <santos137@yahoo.com
Group: AirborneWindEnergy Message: 14595 From: joe_f_90032 Date: 9/20/2014
Subject: Re: Multi-rotor kite-lifted "Coaxial multi-turbine generator" by Ha
Group: AirborneWindEnergy Message: 14596 From: dave santos Date: 9/20/2014
Subject: Re: Multi-rotor kite-lifted "Coaxial multi-turbine generator" by Ha
Here is further prior art ('90) for ST, except for driveshaft.

Nice kite savvy. Likely Harburg can be found kicking yet.


On Saturday, September 20, 2014 7:07 PM, "joefaust333@gmail.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 14597 From: dave santos Date: 9/21/2014
Subject: KiteMill Rising
KiteMill of Norway swooping upward-


Group: AirborneWindEnergy Message: 14598 From: dave santos Date: 9/21/2014
Subject: Shipping News' ongoing AWE drum-beat
Shipping News on Twitter covering SkySails periodically-





 

 

image
 

 
 
 
 

Shipping News on Twitter: "The green future is quite pos...
The green future is quite possible with the application of #WINDENERGY in #ships. pic.twitter.com/tWMnzGlY8x

Preview by Yahoo

 


Group: AirborneWindEnergy Message: 14599 From: dave santos Date: 9/21/2014
Subject: MIT data-mines JoeF for Makani Clues
This may be the last word here until GoogleX-Makani makes some dramatic news public. Its known they have been flying Wing7, to build data hours, so a likely crash may have already occurred without public report. Meanwhile, scant gleanings from past sources; like this MIT coverage, with better-than-average "facts"-

MIT Technology Review

Ted Greenwald on December 27, 2011

Here is documented several claims, some trivial ($.03 kWhr), and some substantive-

"Within two years the company hopes to have an 88-foot wing that generates 600 kilowatts"

The stated window passed last year, and a full M600 design is presumed not even close to finalized. They have to develop bigger motor-generators, as just one terrific problem. Bigger everything. We make some allowance for the loss of poor Corwin for the delay, but the M600 will be a 737-sized monster more-or-less made by kids.

"A gargantuan wing to generate five megawatts is on the drawing board."

Not any more. This is a rare bit of evidence left that the M5 concept even existed, since Makani scrubbed any mention in its web presence.

Totally droll that MIT Technology Review then linked to JoeF's Miles Loyd Page (not KULeuven's actual Loyd paper)-

 

 

image
 

 
 
 
 

Miles L Loyd
DaveS notes:   This from Loyd's classic 1982 paper Crosswind Power- "For auxiliary power, wind-driven electric generators have been used on kites.

Preview by Yahoo

 



Given almost perfect stealth-venture PR control, the linked JoeF page is a unique gap in the Makani-Loyd mythical narrative. The Loyd quote supports the idea excess flight weight is toxic to performance and undermines credibility of GoogleX's flygen gamble:

"DaveS notes:   This from Loyd's classic 1982 paper Crosswind Power-
Group: AirborneWindEnergy Message: 14600 From: dave santos Date: 9/21/2014
Subject: IFO Mountain and Cloud DSing Opportunities
The IFO AWES concept has a great potential to operate exactly as the world-speed-record DS RC gliders do to fly well over 400mph (link below), by using the strong wind shears created by mountains. This is the same dynamic that albatrosses tap, with ocean waves in the mountain role.

Vertical cloud convection is another ready source of strong wind-shears for IFO use, where an energy-glider could operate by dipping in and out of fast rising cloud columns. These shear sources could become a viable resource before higher Jet Stream shears are developed.

Why have these to rich rich shear sources been mostly overlooked? Human glider pilots would have been killed trying to work out mountain DSing to the extreme performance levels the aero-modelers discovered (by breaking many wings). Gliders also are not allowed to fly in clouds (usually). Aero-modelers typically fly their aircraft closeby for radio and visual contact, and therefore do not ordinarily dip blindly into distant clouds.

No suitable mountain or cloud? There is also the option of someday DSing by dipping behind giant kites with IFOs (related to hybrid arch and tethered looping-foil concepts by KiteLab/kPower circle).

CC 4.x BY NC SA

Fun Fact- DSing was predicted by the Third Baron Rayleigh in 1883







Group: AirborneWindEnergy Message: 14601 From: dave santos Date: 9/21/2014
Subject: India's Kite Energy magazine (announcement)
A marginal kite energy notice at present, but AWE will surely figure, and India will be a huge player:

In TheHindu.com, its announced the planned launch of "Kite Energy, a magazine dedicated to kite flying"


 

 

image
 

 
 
 
 

Flying with intent
The simple joy of kite flying reaches greater heights in the hands of Rajesh Nair, a professional kite flyer

Preview by Yahoo

 


Group: AirborneWindEnergy Message: 14602 From: dougselsam Date: 9/22/2014
Subject: Re: Who is an AWE Engineer? (The lies of Dave S.)
Google Search- "No results found for "It takes 10 Watts to remain aloft - final answer"." *** You can't have an honest discussion.  Obviously I was paraphrasing, and I captured the essence of what you had braggingly posted as "the answer" (with the units on both sides of your equation not matching).  I'd say you should just give up on trying to "debate" me.  This is getting boring and I'm seeing no benefit from these interactions that make no sense.
Group: AirborneWindEnergy Message: 14603 From: dougselsam Date: 9/22/2014
Subject: Re: Engineering Credentials?
Sorry... "feeding the troll"...: Doug,...tediously summarize my merit-basis as a working engineer, *** You asked: find "an engineer who agreed with me."  I countered: "find one who doesn't".  That was when you decided to call yourself an engineer. (redefining whatever is convenient so yuo can rpetend you "won" a "debate".  You go on at the level of a child.  This discussion is SO FREAKIN' LAME.  Just shut the hell up!  God. How YOU, of ALL PEOPLE, can call anyone a troll, is laughable.  Please, just go away.  No need to mention me - just forget I exist, please.

Group: AirborneWindEnergy Message: 14604 From: dougselsam Date: 9/22/2014
Subject: Re: Progress in AWES R&D (utility-scale)
Pierre: I try to discern what you mean when you write.  Don't worry if you don't get every nuance (french word?) of the English language correct.  Nobody expects you to have perfect English.  Your English is probably way better than anyone else's French.  By the way, I read last night that since the Norman invasion, 30% of English IS French.  Also: English has more words than any other language - I think the next down the list is German with less than half as many words.
Group: AirborneWindEnergy Message: 14605 From: dougselsam Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)
"A marginal kite energy notice at present, but AWE will surely figure, and India will be a huge player:" ***Dave S. Lie-Watch: 1) "a kite energy notice": The notice is of a "planned launch" of a KITE MAGAZINE, coincidentally using the NAME "Kite Energy" (capitalized) - we have no indication at this time that it is a "kite energy" (uncapitalized) announcement, as pertains to the subject of this Yahoo list.  Instead it is announcement of a planned launch of a kite magazine, with no other information given.  Everything else, you JUST MADE UP out of THIN AIR. (Lies about the present)

2) Related "AWE will surely figure" ***IF AWE does NOT figure, then this phrase will turn out to be lie #2. (Lies about the future)

3) "India will be a huge player:" *** If India is NOT a huge player, then this will turn out to be lie #3. (more lies about the future)

What amazes me is, after being flagged as a consistent liar, your wanton disregard for the truth pushes you to stack up lies faster than you can stack up kites:  3 probable lies in ONE sentence.  And that is normal for your writing.

Just for the record, an honest sentence might read: "A planned kite magazine notice at present, but AWE may figure, and India could be a huge player:"

The problem with pathological liars is they are so far out on the lying curve they can't even see that they lie more naturally than they breathe.
Group: AirborneWindEnergy Message: 14606 From: dave santos Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)
Doug,

Its quite true, if AWE does go away, then the idea India will figure hugely is mistaken. We are here offering to support the AWE coverage of Kite Energy Magazine, so expect that aspect to come true.

Strange if you do count "All roads lead to the SuperTrubine" as a "lie", if India is a lie. In fact we have Indian AWE players already (for example, SkyMill's partners, and TRV).

AWE is not going away yet! Thousands of signs signals  this, not just your own ongoing  fevered presence,

daveS



On Monday, September 22, 2014 9:30 AM, "dougselsam@yahoo.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 14607 From: joe_f_90032 Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)
A kite magazine about kites would de facto be serving AWE.
~ JoeF  
Group: AirborneWindEnergy Message: 14608 From: dave santos Date: 9/22/2014
Subject: Re: Engineering Credentials?
Doug,

I did not just start calling myself an engineer to answer you as such. I have been a working engineer for decades, under the formal definition cited to you, that Joe pointed out you wrongly overlooked.

The problem I am having with your latest challenge is that no engineer in AWE I am in contact with agrees with you, but if they were to publicly contradict your technical opinions (say about ignoring scaling law, or neglecting aero-drag in flight physics), the expectation is that you would resort to profanity and crude insult, rather than patient rebuttal with referenced facts. You are even now bordering on sliming JoeF (for agreeing drag-factors count in keeping mass aloft by lift), apparently unaware of how unjust that is. We really work hard to share AWE progress where you see no progress, and just piss on the AWE work of others.

You are not in a position to ask improbable favors ("forget [you] exist") of those you accuse by manufactured quotes and emotional arguments. The Forum discourse will continue to correct you factually as the need arises, and also keep sharing the ongoing wonder of kite energy. If you are also able to cheerfully share engineering progress and useful methods, you can be a happy camper too,

daveS


On Monday, September 22, 2014 8:36 AM, "dougselsam@yahoo.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 14609 From: dave santos Date: 9/22/2014
Subject: Re: Multi-rotor kite-lifted "Coaxial multi-turbine generator" by Ha
Rudy is alive and well and eager to be an active AWE player again, as he has just retired from a successful business career. His location in Boulder Colorado is quite apt, given the glacial (gov-speed) shift to active NWTC AWE participation.

We Welcome Rudy Harburg Warmly into the global AWE community.


On Saturday, September 20, 2014 9:16 PM, dave santos <santos137@yahoo.com
Group: AirborneWindEnergy Message: 14610 From: dougselsam Date: 9/22/2014
Subject: Re: Engineering Credentials?
"Doug,I did not just start calling myself an engineer to answer you as such. I have been a working engineer for decades" *** Stop lying.  You suddenly began calling yourself "an engineer" in response to my challenge to find an engineer who disagreed with my statement that the energy to keep a 1 kg kite loft would approach zero as its area approached infinity.
Group: AirborneWindEnergy Message: 14611 From: dougselsam Date: 9/22/2014
Subject: Re: Engineering Credentials? Technician...
The credential of an engineer, as opposed to a technician, is normally an engineering degree. An engineer knows how to get units to match on two sides of an equation, as a minimum first step, beginning in high school.  A technician uses his hands to make things.  There are usually many technicians for every engineer.  You are fooling nobody but yourself.  I do not recall you calling yourself "an engineer" until you suddenly decided that would be a clever way to respond to my throwing back your challenge to "find an engineer who DISagres with me" into your court.  Everyone on this list was a witness to this.  To claim otherwise is just one more of your daily multitude of lies.  You always think you explain your way out of your lies, but only by your own lying (lack of) standards.  Have fun lying.
Group: AirborneWindEnergy Message: 14612 From: dave santos Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)
Not only is Kite Flight a central to most AWES concepts, but the thriving world of kite enthusiasts is becoming aware of AWE R&D, and we see a wealth of kite talent ready and eager to enter the effort. 

The primary means for creating this mass awareness within kiting is the collective media-scape of kite magazines and online content. Drachen Foundation's Journal, with DaveL's classic 2004 AWE survey, is just one example of kite magazine coverage that actually goes back decades, and is only growing. The AKA magazine is naturally publishing more AWE news, and expanding power-kite features (the extreme-sport outlier status has faded). The AWES Forum is a kite-forum at heart (but we also welcome IFO and other non-kite AWE discussion).

Indian talent is already a strong player in early AWE, as a careful accounting of the AWE community will show. An ideal story would be to feature the AWE R&D with Indian participation already in place (like Dr. Jitendra Goela at WPI, as a longtime AWE pioneer, and Dr. Jayant Sirohi's Rotor Lab newly entering into active research).

Its up to us to reach out to Kite Energy India, to make its AWE coverage awesome, and help India surely become an AWE superpower.






Group: AirborneWindEnergy Message: 14613 From: Baptiste Labat Date: 9/22/2014
Subject: Reconciliations
Hi all,

Here is my answer to several related different posts in the previous days :

Is Minimal-Mass-Aloft an AWES Design Golden Rule?/Can Dave Lang answer Joe's Question/Minimum Drag ("aviation power curve")/Powered Flight (fresh start)

But first, Doug and Dave, can you please stop arguying on this mailing list, and think twice before posting things on subject you do not master? It is like spam to me, and as a result I nearly don't have time to read you, it is in my opinion the main reason you don't have any answer from anybody...


1) Parachute example
The parachute example of Doug is right to my opinion.

The larger, the parachute will be, the lower the sink rate will be, and the lower the power at equilibrium will be . Maybe a few equations (are we engineers?) might help (notations are obvious) :
Weight=m.g
Drag = 1/2*rho*S*Cd*V*V
At equilibrium you have
Weight = Drag
You can then solve the equilibrium speed
V= sqrt(2.m.g/(rho*S*Cd))
The power is then P=V.Weight = m.g.sqrt(2.m.g/(rho*S*Cd))

If you make the assumption of a massless parachute, this power can tend to zero as S (the surface) increases.
However, you are still falling not staying aloft, so this is not the correct answer to the question.

2) Airfoil
To be able to "fly", to my knowledge you need lift.

If we now consider an (air)foil (kite or plane), and a given wing, a good model of the loads on the wing in "static" flight, is given by lift and drag curves.
I have already given an answer in a former post https://groups.yahoo.com/neo/groups/AirborneWindEnergy/conversations/messages/12414, with clarifications in following threads, so I won't repeat myself here.
I think the 10W for 1kg figure of Dave came from here, but it's not an absolute value. One important point is to understand drag and lift depend on the angle of attack.

If the size of the wing is fixed, you may find an optimal speed to reduce the power to fly (I think this corresponds to the curves Dave sent, where the angle of attack is varying to keep equilibrium)
If the speed is fixed (kite case) you can find an optimal wing size to reduce the power extracted from the flow. If the wing is smaller, the angle of attack will need to be higher, and you will not be at the maximum of the lift over drag curve (and not really as high as you can).
If the wing is larger (by homothety), you will have added drag for no more lift.
I think this is what Dave is considering, for a given wing shape, you will find an optimum, which is the practical case you face everyday in aviation or kiting.

However, this does not contradict Doug point of view, where you both reduce speed and increase wing size. In this case, the power can go to zero (at least as long as you stay in the same Reynolds number range), as drag is staying the same but relative wind speed reducing. However, this case is unpractical for many reasons, first because you cannot reduce the wind as you will.

So I think both of you are deaf to other (not dumb for sure!), even if both of you can be partly right (and mostly wrong to insult others).

The third point of view is Joe's one, where you do not change the wing size but increase it's aspect ratio.

If you consider inviscid flow theory, and according to the Lanchester–Prandtl wing theory and formulae reminded in http://en.wikipedia.org/wiki/Lifting-line_theory the lift to drag ratio can be increased linearly with the aspect ratio, so that the required power could go to zero for a given speed and a given wing area.

However, I don't have a clear cut answer to how far the lift to drag ratio can be increased by increasing the aspect ratio for a given wing size when accounting with viscous drag.

I might be unclear, or have made some errors. Please write me directly not to pollute this forum, and I will correct the post with due aknowledgements.

++
Baptiste
Group: AirborneWindEnergy Message: 14614 From: dougselsam Date: 9/22/2014
Subject: Re: Reconciliations
Baptiste:  I still have not seen anyone comprehending my explanation, which has to do with momentum versus kinetic energy.  Momentum is mv, whereas kinetic energy is 1/2mv^2, so as flow speed increases, kinetic energy increases faster than momentum. 

Since power to keep the kite aloft is kinetic energy per unit time, if you can reduce the kinetic energy in the downdraft that holds up the kite, you can reduce the kinetic energy per unit time, which is power. 

Mother nature dictates that the momentum of your downdraft holds up the kite, but you can CHOOSE to accomplish this momentum by using more air volume in your downdraft, at a lower speed.  The momentum is the same, the kinetic energy is lower. 

Assuming geometric similarity (no change in aspect ratio) for simplicity, if you double your kite area, you can push twice the volume of air down.  To get the same momentum exchange as the smaller kite, you can then halve the downward velocity.  When you halve the downward velocity, you impart 1/4 the kinetic energy, which, even when multiplied by the doubled volume still uses only HALF the total energy per unit time, (which is power) to lift the same weight (call it 1 kg). 

So, double your wing area, and, for the same weight, you use HALF the power.  This is an idealized case, of course.  A moment's reflection by anyone with even a child's level of aviation awareness bears this out:  It's well-known that a design using less wing loading requires less power to fly.

Any idiot knows gliders have more wing per unit weight so they can remain aloft using less power.  Why does the Gossamer Albatross require so little power for its weight to remain aloft?  A large wing area compared to its weight, that's why, and it is not in question, but in fact a well-known rule-of-thumb in aviation.  Repeat: This is NOT MY OPINION, but instead, one of the most basic facts of aviation and airplane design.  More power requires less wing to stay aloft.  Less power requires more wing to stay aloft.  Period.  End-of-story.

Regarding your other point, it would be nice on this forum if anyone could actually reply to any simple point without trying to turn it into a lying word-game.  I don't enjoy it either.  It's interesting to step back and witness the lying desperation of someone who can't balance units across an equation suddenly declaring themselves "an engineer" in an attempt to try and seemingly win an argument.  The thing I'm still wondering is, why do they want to have an argument in the first place?
Group: AirborneWindEnergy Message: 14615 From: dougselsam Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)
"A kite magazine about kites would de facto be serving AWE.~ JoeF"
*** It COULD not necessarily WOULD, since nobody knows if kites will even play a role, if and when a successful AWE may be developed.  All it takes to change a hopeful statement to an outright blatant lie is one letter.  Joe, I know it is not YOUR intent to lie, so I'd be careful which words you use.  If you make statements in the absolute, about topics that involve uncertainty, there's a high probability the "absolute" statement could turn out to be untrue.
Group: AirborneWindEnergy Message: 14616 From: dave santos Date: 9/22/2014
Subject: Re: Engineering Credentials?
Doug,

You substituted a statement that I did not address (that still neglects drag factors!) somehow expected it to settle the question. My corrections were specific to several other misstatements you made, like 

"The albatross ideally likes to soar, using ZERO energy to stay aloft. "

In fact, as Wikipedia's DSing article supports, the Alabtross is acting as a WECS, and you stand corrected by a working engineer,

daveS
Group: AirborneWindEnergy Message: 14617 From: Pierre BENHAIEM Date: 9/22/2014
Subject: Re: Progress in AWES R&D (utility-scale)

JoeF,


Conventional wind towers have a standard as 3-bladed turbine. AWES should have a standard in a same way. By analysing parameters and making some trials such standard can be found. Actually in the world of universities and companies reel-in/out method works as temporary standard, being not marketed. In my opinion this method does not allow a maximization of space, but is still preferable in many other studied methods.

 

PierreB,

http://flygenkite.com

Group: AirborneWindEnergy Message: 14618 From: dougselsam Date: 9/22/2014
Subject: Re: Engineering Credentials?
Doug, misstatements you made,..."The albatross ideally likes to soar, using ZERO energy to stay aloft." ***he LIKES to use zero of HIS OWN energy to fly, when possible, as many birds prefer when conditions are fertile for soaring in any form.  Obviously, soaring uses the energy of the wind.  Sorry for your inability to read between the lines, to understand engineering conversations, to understand humor, to understand sarcasm, to comprehend shorthand language used to illustrate a point.

"and you stand corrected by a working engineer daveS" *** Your desperation to always "seem" to win every argument, no matter how many lies upon lies it may take, is really bad.  In this case you are STILL trying to rationalize NOT being able to come up with an engineer to refute my point (that has no refutation available), by maintaining your recent fiction that you are "an engineer". 

Have fun lying, and lying more, attempting to bolster your previous lies.  As Dave Lang et al have pointed out, the only reply to you involves going over remedial high-school material.  That is NOT indicative of "an engineer".  Not sure how long you want to go on with THIS lie - don't you have more new ones that are more important?


Group: AirborneWindEnergy Message: 14619 From: Joe Faust Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)
Successful AWE is extant on earth today. 
Kites do today play a role in today's successful AWE. 

~ JoeF

Group: AirborneWindEnergy Message: 14620 From: dougselsam Date: 9/22/2014
Subject: Re: Progress in AWES R&D (utility-scale)
"reel-in/out method works as temporary standard, being not marketed"
*** Reeling is an artifact of mental laziness, not comprehending the real solutions.  People try it because it is easy to understand, and can be accomplished using a kite that can be purchased. 

Reeling is "being not marketed" like so many wind energy "inventions" that cost too much for the amount of energy they can provide, because it was a bad idea, and the results bear this out.  The idea is to provide wind energy at a lower cost per kWh, not a higher cost.  Many with a better understanding would not have wasted their time with reeling. 

Certainly by this point, one might expect to have heard some good results if reeling, per se, were really a good method.  To me, I don't think a cursory initial assessment would rationalize a reeling program.  Nonetheless, the first few people trying it could perhaps be forgiven, in the sense of "hey, ya never know..." but by now, it's approaching the level of a trip to Vegas as an investment: It might seem to work out for a moment or two, but at some point it will become obvious that it was a bad idea.
Group: AirborneWindEnergy Message: 14621 From: dave santos Date: 9/22/2014
Subject: Re: Engineering Credentials? Technician...
Doug,

Unfortunately, the professional engineering definition statement on Wikipedia provided to you does not support your narrowly self-serving definition*.  My career work overwhelmingly qualifies under the professional definition.

Identifying for you the ST's driveshaft scaling-law limitations (and many other ST problems) was more than a technician's task, it required serious engineering insight. Sorry if the bad news was not what you hoped,

daveS


* Professional engineers do make math errors, and ideally correct them without undue fuss.


On Monday, September 22, 2014 12:08 PM, "dougselsam@yahoo.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 14622 From: dave santos Date: 9/22/2014
Subject: Re: Engineering Credentials?
I'll stick to the professional definition provided, with Joe's support. Good luck with your troubles.


On Monday, September 22, 2014 1:41 PM, "dougselsam@yahoo.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 14623 From: Joe Faust Date: 9/22/2014
Subject: Re: Progress in AWES R&D (utility-scale)
​Interesting proposal, PierreB, about a "standard." The branch of wind power that has the three-blade prominent is acknowledged as important. In this discussion, I would not want to lose that AWES world is holding many branches of activity including but not limited to towing, lifting, and electricity generation. ​IFO adds another arena. Such branches may one day see some gelling to a "standard" for certain popular scale or purpose. The recent decades of first fervor in AWES has had high participation with the groundgen reeling method. 
     Consider rushing the scene and have soft kite be lifter tail-stabilized by tri-blade flygen or driver of looped rope for groundgen; presto standard candidate!    However, without even one professional prized competition for electricity-generating AWES at an affordable scale, a "standard" is probably a good distance into the future. 
    ~ JoeF

Group: AirborneWindEnergy Message: 14624 From: dougselsam Date: 9/22/2014
Subject: Re: India's Kite Energy magazine (announcement)
"Successful AWE is extant on earth today. ~ JoeF"
*** Depends what you mean by "success".  So far we have demos, but no demonstrated savings from adopting AWE technology.  If your standard of "success" is "succeeding in a functioning demo" then yes, there is success.  What most people would refer to as "success" is, once the demos are complete, can the technology compete SUCCESSFULLY with other technologies, and become an actual industry.
"Kites do today play a role in today's successful AWE."
***To the extent that demos can be called "success". but not to the extent of outperforming existing technology.


Group: AirborneWindEnergy Message: 14625 From: benhaiemp Date: 9/22/2014
Subject: Criteria towards an AWE standard (for electricity production)
    • Launching and landing (possibility of automated launching and landing)
    • Maximization of land and space used (ratio of power/land and space used)
    • Reliability (stationary systems are favored)
    • Maintenance (systems making less stress in materials are favored)
    • Possibility to fly at high and very high altitudes (a standard should be used for all altitudes to reduce general costs in R&D)
    • Possibility of secundary use of land
    • Ease of road marking by lighting allowing visibility
    • Lifetime of elements 
    • Costs in materials (in case of cyclic irregularity of production, expensive devices smoothing production are needed _ supercapacitors or others _ and stresses are expected) 
    • Quality of electricity production (so no cyclic irregularity of production or smoothed production)
    • Ease of transport of (not too big) elements
    • ?

Actually no system (at least from companies and universities) gathers, or is expected to gather these criteria. Please have you another order of criteria?  

 

PierreB

http://flygenkite.com

Group: AirborneWindEnergy Message: 14626 From: dave santos Date: 9/22/2014
Subject: Re: Reconciliations
Baptiste,

I strongly disagree with your parachute defense. Doug was invoking real wings like the albatross flight example as a "zero power" flight process. Even an "tending to infinite" parachute example is invalid, since it is not at all realistic, and does not really maintain flight, but only slows certain descent.  You do not propose a powerless method for blowing air up under the parachute (esp. within the weight budget). You (and Doug?) introduce the parachute wrongly, I think, and only fall into Doug's basic error thereby.

The fully correct answer is already given: that drag factors for lift-based flight require power to overcome, for maintaining mass aloft.  Note my second-approximation result of 3.8W per kilo to sustain flight. The 10W number is invalidated by real cases.

Recall that my example of the Tacoma Narrows bridge oscillating contradicted your calculated result that oscillation of a comparable-sized wing would not self-oscillate in wind. It would not be SPAM if you persist to calculate where your model failed. Thanks for allowing you can make math errors, even if you dislike errors to be corrected in public. As long as they get corrected, its good.

The AWES Forum ultimate destiny is to be a data mine. As long as there is useful knowledge being shared for mining, the SPAM factor has not won. The early AWE winners may be those who best endure Forum noise to get at the essential knowledge.

Thanks for trying to make it easier to follow the Forum,

daveS













On Monday, September 22, 2014 12:54 PM, "dougselsam@yahoo.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 14627 From: dave santos Date: 9/22/2014
Subject: Micro-Disturbances in AWES Winds
Wind variability for AWES operations is still a poorly understood mostly overlooked topic, in most circles. Its quite common for wind at our target altitudes (KitelLab, kPower, etc.) to vary suddenly, and even reverse strongly, in transient events. Kites are suddenly tumbled, as if in a washing machine, and can just fall out of the sky, as observed many times, from Texas to the Pacific NW.

These upsets are caused by local small-scale vorticity self-similar to larger-scale vorticity. The commonest  Micro-Disturbance event is a vertical vortex too weak to create a visual dust-devil or waterspout, but able to reverse wind direction quickly and strongly as they pass. More-rarely a horizontal vortex passes as either a breaking gravity wave over an inversion, or line vortex ahead of a micro-front (virga is a common cause of these local down-burst "book-end" formations in the wind-field). Disturbed shear-zones within the vertical gradient, and hodographic spirals are common under-documented AWES disturbance effects as well. Its proposed that large kitefarm arche units will tolerate Micro-Disturbances far better than small units, by having a larger characteristic dimension than small-scale turbulence able to upset small units.

Micro-Disturbance frequency apparently varies by many factors, like lapse-rate, terrain, season, etc., but random strong disturbances happen every few days or weeks, with major (unforecast) events a few times a year. Disturbances often occur in packets. This is bad news for AWES dependent on high-risk platforms (high-mass high-velocity high-complexity), but a tolerable nuisance for low-complexity "rag-and-string" kite methods. Fast moving AWES flying large patterns will not always detect local disturbances before suddenly entering them at high-velocity. Max load limits can be exceeded, even if control is maintained.

While the disturbance events definitely emerge in extended flight testing, they are not yet logged by AWE engineering science as hard data, due to initial practical limitations and lack of academic interest. Nevertheless, the prediction is here repeated that these events will be found in geophysical data sources, as imaging technology continually improves. NASA JPL offers Martian data at least-


 

 

image
 

 
 
 
 

Winds, dust devils and more
JPL held a press conference today to talk about weather and radiation results from the first 90 sols on Mars. The main topics from the REMS weather experiment were ...

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kPower's consulting meteorologist, Storm Waters, replied to a prior posting of this material-


This all makes perfect sense to me-even though i actually deal way more 
in the meso & macroscale realm. Mesoscale organizations (like 
thunderstorm complexes & squall lines) are not completely discrete w/in 
their ambient environments-& such microscale turbulence can emanate form 
(or otherwise develop as a result of) such mesoscale organizations 
(however distant). If lack of evidence in academia is due largely to 
lack of interest from academia-deducing they don't happen is ludicrous 
at best.

Group: AirborneWindEnergy Message: 14628 From: dave santos Date: 9/22/2014
Subject: Re: Who is an AWE Engineer? (The lies of Dave S.)
Its only "obvious" that you are faking quotes when a search finds no hits.This is a recurring problem where you use quote marks to create the false impression that you are quoting accurately, rather than unfairly paraphrasing to suit your biases.

Calling anyone a liar in public with faked quotes cannot make up for your lack of technical progress to share with us, in friendly professional language.


On Monday, September 22, 2014 8:28 AM, "dougselsam@yahoo.com [AirborneWindEnergy]" <AirborneWindEnergy@yahoogroups.com
Group: AirborneWindEnergy Message: 14629 From: dave santos Date: 9/22/2014
Subject: DIY Drone AWE discussion (past years)
Chris Anderson seems like the lead voice for AWE in the DIY Drone circles. Perhaps there is fresh ongoing discussion to find, meanwhile here is the early discussion-


 

 

image
 

 
 
 
 

Another use for UAVs: generating power
There's a good profile of Saul Griffith in last week's New Yorker. One of the companies he started, Makani Power, wants to use tethered UAVs (shown above) to…

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DIY Drone Power Kite? KiteGen Kite to Generator flies a figure 8 to be a pump generator.
Where would this post go to reach the members and fit best?   Hi I am interested in KiteGen and power generation using LARGE Kites for high altitude wind power…

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Group: AirborneWindEnergy Message: 14630 From: dave santos Date: 9/22/2014
Subject: Re: Reconciliations
Baptiste,

I reread carefully your original post and offer the following observations-

First you say Doug is "right" about a "parachute" model, but my search of old messages does not find any Doug "parachute", but "wing" and "albatross" ( and several "zero" results, without "trending toward", which does not, in any case, make it quite "right"). If you are in fact the creator of this parachute model that is "right", at least describe this canopy better (does it have lines and ballast mass? Is it finite? Based on real engineering materials? Stable? You do not say). You conclude however by seeming to say Doug is wrong, at least for a "massless" case, which is very confusing (You write: "not the correct answer to the question" after starting with "right")

I do not think its helpful to AWE engineering (nor provable factually), for you and Doug to invoke "infinite", "massless", "inviscid" cases, even if the math is claimed perfect. Its GIGO in practical terms. Both of you Please Note: Equations are introduced in primary school, and Engineers are far better defined by the professional description cited, than your weaker standard that also logically applies to kids doing correct math as an exercise (not actually creating an engineered technology).

Moving on to the Powered Flight case (where real aircraft have real power sources), my "10W per kilo first approximation" did not derive from your L/D5 calculation. A careful reading of my comical effort shows I attempted a more fundamental physics calculation, without invoking fluid dynamics (as a start). Its not so shabby that my attempt happened to match your fairly average wing case.  Then I went further to suppose that L/D20 (rounded-up Condor number) was a reasonable realistic aspiration (Ampyx range). The 3.8W second appoximation seems to me a sound calculation that you did not identify any error in (I do not see a "significant digits" problem with this second approximation that you warned off-forum).

There is an old loose-end I ask you to resolve- You never did account (as far as I remember) why your calculated result, that a giant wing would not self-oscillate in win, is at odds with the obvious fact the Tacoma Bridge did self-oscillate. I proposed that subharmonics develop in the wing parts that cascade up to bulk oscillation. Was not my heuristic logic result more sound than your prediction?

Sorry for my part in the annoyance involved in getting to more realistic engineering predictions for AWE, which is a team effort, for top results,

daveS
 
Group: AirborneWindEnergy Message: 14631 From: Baptiste Labat Date: 9/23/2014
Subject: Re: Micro-Disturbances in AWES Winds
Thanks for this interesting topic Dave.

Let me balance the view that low-complexity "rag-and-string" kite methods will be less perturbated than high-mass high-velocity high-complexity.

First a fast wing will see less relative change in relative wind that a slow wing. If you ever go planning in windsurfing, you will feel in your arm what I say.
Moreover, the more inertia you have, the more you will filter high frequencies perturbations in time.

As said, the larger you are, the more you will be able to filter out the high frequencies in space.

But on the other hand, it means that you will not be able to retrieve the small scale turbulence energy (which I can tell you some birds do after long observation, even if I have never read anything about this. Can I call it "turbulence soaring"?).

++

Group: AirborneWindEnergy Message: 14632 From: Rod Read Date: 9/23/2014
Subject: Re: AWES Torque Transfer via Tensegrity Tensairity Towers (TTviaTTT)
Bleahhehehe Sacrifical Lamb, Ram Rod here.
Expletives.
WTF?

How anti science have you gone Dave Sandtoss ?
I'm going to leave it to you.
Cause I can't rightly be arshed being a Doug to your impending onslaught of writhing in word form.
Here are your statements...
Just pretend I said them all...
Tell me please... (Honestly try this and don't be a bell end if you answer.)

What percentage of what's implied here is useless?



we have to throw away still scarce human AWE effort in theoretic dead-ends, just for those who cannot see them.

Every expert kitemaker is familiar with the scaling limits of sticks in the sky. The admonition to "test everything" is more symbolic than literal. We do intend to test "lead-balloons", for example. In any case, Rod is our Sacrificial Lamb here; and his torque-ladder efforts should reveal the predicted operational and scaling barriers.

If a large AWES HAWT hub-shaft is wanted, the albacore-form balloon is a baseline design to beat. Note that Brooks had a concept for torque transfer via a chain of round balloons

I would never have chosen torque options as a good challenge. The real challenge is any scalable AWES that beats all others.

Extra weight means more drag too. Somewhere else in the system more wing is needed to lift it, so more drag.

The balloon can be buoyant. Frontal form drag is nicely offset by vectoring more flow into blades.

While the balloon has more skin-drag, the torque-ladder has high rotational form drag. These look to mostly cancel.

To win the challenge honestly requires side-by-side testing, and a strong personal down-select to torque dependence.
The torque ladder is tensegrity if Rod leaves out the side and central spars, and just leaves the the crossbars. The ladder would briefly pre-load (take out slack) at the beginning of a session. Note that Rod is trying to reduce the problems of pure tensegrity that he is discovering by hands-on testing.


Rod Read

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

07899057227
01851 870878


Group: AirborneWindEnergy Message: 14633 From: Rod Read Date: 9/23/2014
Subject: Re: Criteria towards an AWE standard (for electricity production)
Switch-able power take off from AWES to Generators
Swappable components for maintenance and upgrade
No single point failures
Automatic recoveries and shut-down on monitoring for failures
Acoustic monitoring?
Ground gen connection standards.
anchoring standards

Rod Read

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

07899057227
01851 870878


Group: AirborneWindEnergy Message: 14634 From: Rod Read Date: 9/23/2014
Subject: Re: Reconciliations
Can we get over this yet?
A wing needs air moving past.
either it's pushed or pulled forward to work ... or lifted by air with a vertical component to stay aloft.

For a level field with zero moving wind. a kite wont work . some form of propulsion will be needed to get the necessary flow.
Different wings require different propulsion to achieve similar characteristic results.

We don't need to be looking toward only doing the ultimate scale effort before we start otherwise nothing will be done ... not even along the way to that nowhere.

Great 3.8w, KW, elastic bands or horses don't give a toss.
lets find out what exists, use it and improve it

Rod Read

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

07899057227
01851 870878


Group: AirborneWindEnergy Message: 14635 From: Rod Read Date: 9/23/2014
Subject: Re: Micro-Disturbances in AWES Winds
I'm willing to risk my limited reputation here...
I'm going to bet that PILOTS are into knowing about turbulence too.
Radical suggestion I know, but if we meet one imagine what they could tell us.

Rod Read

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

07899057227
01851 870878


Group: AirborneWindEnergy Message: 14636 From: Rod Read Date: 9/23/2014
Subject: Does this clutch exist yet


I'm looking for a clutch which engages based on axial tension...

e.g. when the input torque shaft tries to pull out of the clutch with enough force...

The output plate is engaged

Do you know of any clutch design which fits this criteria?

This would help with any spaced ladder transmission. where by you want a tight lift line before trying to transmit torque so that the ladder does not over twist.

Really struggling to find one off the shelf... Seems like a really easy thing to make
Surely somewhere..

Group: AirborneWindEnergy Message: 14637 From: dougselsam Date: 9/23/2014
Subject: Re: Reconciliations
"First you say Doug is "right" about a "parachute" model, but my search of old messages does not find any Doug "parachute"" *** I cited the fact that a larger parachute falls slower than a smaller parachute, for the same weight.  (Your search didn't work, and you've missed reading important points).

This was an attempt to explain what should be obvious, requiring no explanation:
A larger surface area allows a weight to be held aloft using less energy.  In the case of the parachute, the power is the potential energy of height being "used up" as the parachute falls. Or consider a fan blowing an updraft to keep the parachute in one place.

The general idea COULD BE described USING THE LANGUAGE OF MATH as commonly seen in the fields of SCIENCE AND ENGINEERING, that the power required to keep a given mass aloft APPROACHES zero as the area APPROACHES infinity.  This is shorthand language so the educated reader can imagine the shape of a graph of power/area.

Note: NOBODY using this terminology actually BELIEVES that the ZERO power, or the INFINITE area could actually be reached.  They can only be "approached", and are illustrative terms denoting asymptotic trends in a hypothetical graph of area versus power required.

Being unfamiliar with the shorthand mathematical language of science and engineering, one might mistakenly believe the engineers are really talking about an infinite area or a zero power situation, but that is an erroneous interpretation.
Group: AirborneWindEnergy Message: 14638 From: Rod Read Date: 9/23/2014
Subject: Smart atom spaxels
Group: AirborneWindEnergy Message: 14639 From: dougselsam Date: 9/23/2014
Subject: Re: Who is an AWE Engineer? (The lies of Dave S.)
"you are faking quotes when a search finds no hits...a recurring problem...unfairly paraphrasing".  *** I use ellipses (3 dots) to condense quotes, apparently making it difficult 4 U to find the original text.  Your fixation on "searching" to try and "win" arguments reveals two things:
1) You're not paying attention, so you don't remember who said what;
2) You're wasting your life away on nothingness.
The second point concerns me if I let you suck me into the same activity -  a poor use of time - gotta run - have a day.