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Re: [AWES] Fwd: Energy-Harvesting Gliders

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  • Dobos, Gabor
    ... Hello Dave, As I told, I like this question. A short answer to your question is “YES”. Would you like to hear some more details? “Yes, but not by me,
    Message 1 of 25 , Jun 12, 2013
      On 2013-06-11 00:28, Dobos, Gabor wrote:
      On 2013-06-10 03:02, David Lang wrote:
      Gabor,

      I have enjoyed your concise and thoughtful responses. Thanks.

      I am curious about something. It seems that there is the underlying assumption in your scheme that the "gradient soaring process" is a robust energy cycle, meaning that after maintaining, on-the-average, a steady-state spatial location (ie. a cycle that will not drift continuously downwind), that there is enough surplus energy left over to cost effectively be harvested and transmitted to the grid.

      To this end, has there been any time-domain simulations of this process (including due regard for the drag effects that airborne harvesting devices would visit upon the glider's performance)?

      regards.

      Dave Lang (DaveL)



      Hallo Dave,

      It is a very good question, and you will receive a very good answer soon.
      Gabor

      Hello Dave,

      As I told, I like this question. A short answer to your question is “YES”. Would you like to hear some more details? “Yes, but not by me, or rather....”. All the details you can find at the end of my script.

      But prior to answering, I have to make clear something. Something that is probably unusual in this community. I have to tell you that I have never sat in a glider, never tried hang gliding, parachute, kite flight, etc. Therefore, you will probably have some doubts concerning my explanations to the topic. In your place, I would probably also have doubts regarding the words of an outsider. Yes, though I became a member of this community, (thanks to Joe Faust's kind invitation), I am an outsider, since I never formerly had any physical contact with these very exciting things. (Except my childhood flying toy-kites, made by my father.) It is right to ask then, how I dare speak to you about this topic, which is definitely yours and not mine?

      It happened step by step. Originally the trivial drawbacks of traditional wind power plants (fluctuations and low intensity of surface winds and the low capacity factor of about 20-30 % of conventional WPPs) made me to think about a better solution. Capitalization on the much more intensive high altitude winds seemed to be a useful possibility. But this isn’t a simple task, since it is impossible to build wind towers that are several thousand meters tall. Therefore, I invented the tethered flying devices :-)      for this purpose many years ago. But upon investigating the literature, it became clear in a short time that I was neither the first nor the only inventor of this solution. This flop was the impetus to begin the systematic investigation of the patent- as well as scientific literature of the topic. Therefore, by today, I am probably in a position to answer your very right question, though I am not an expert neither in this field nor in most of other fields of this multidisciplinary project. I am afraid nobody is competent in all components of this project, since there are no polyhistors today. I am not one. But I hope that I have a deep insight into the components of my “IFO” (Identified Flying Object, the name of my energy harvesting device). If not, I don't hesitate to ask an expert. It is the reason why I like if somebody can find the right questions. You can!

      Returning to your question, I can say that simulation is an early ambition of researchers dealing with this topic. As you know, we learned Dynamic Soaring from the sailing birds like the albatross. These birds are able to fly in any wind in any direction while hardly moving their wings. They mostly utilize wind energy for their flight. A lot of publications discuss the explanation of their secret. Today, the flight mechanics of the sailing birds is clear, the equations of motion are well known, the mathematical implementation of their flight is possible, and there are flight simulators capable of simulating DS flight.

      You can find and download a very nice computer simulation of the albatross' motion at: http://www.howfliesthealbatross.com (Find picture 2. on this site and follow instructions.) Phil Barnes, the author of this simple but very expressive simulation is of course familiar with the flight mechanics of albatrosses, and he has several publications on this topic. You can find his contact details and the link of publications on the previous link.

      By understanding the theoretical details, it became possible to plan the trajectories of the DS-flight, e.g.:

      Optimal patterns of glider dynamic soaring by Yiyuan J. Zhao, Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, MN 55455-0729, U.S.A.Optimal Control Applicatons and Methods, Volume 25 Issue 2, Pages 67 - 89., Published Online: 11 May 2004

      Heuristic control of dynamic soaring. by Wharington, J.M.,  Control  Conference,  2004. 5th Asian  Volume 2, Issue , 20-23 July 2004 Page(s): 714 - 722 Vol.2

      and choose the most efficient ones from an energy-saving point of view. The aim of the research in this field is to „teach” unmanned aerial vehicles (so called „UAV”-s) to „think” like humans and to make bio-inspired, or rather, human-inspired decisions over the course of their flighti. Of course, this knowledge is not our own, but borrowed from sailing birds. Therefore, it would be more promising to let our UAV-s mimic the instinctual motion of these birds. Today, many researchers engage in so-called „biomimetic behavioural engineering”. These researchers write and test computer programs that (by making „bird-inspired decisions”) can guide the motion of the UAV-s in the manner that sailing birds and their evolution have developed in the past several billion years. This way, we do not need to waste so much time with it:

      Bioinsp. Biomim. 1 (2006) 76–88 doi:10.1088/1748-3182/1/3/002. Design of a bio-inspired controller for dynamic soaring in a simulated unmanned aerial vehicle. Renaud Barate, St´ephane Doncieux and Jean-Arcady Meyer, Universit´e Pierre et Marie Curie—Paris 6, UMR 7606, AnimatLab/LIP6, 8 rue du Capitaine Scott, Paris 75015, France

      Sachs published a very interesting paper from a practical or rather energetic point of view, dealing with the minimum shear wind strength required for DS of albatrosses:

      2004 British Ornithologist Union, Ibis, 147, 1-10 , http://onlinelibrary.wiley.com/doi/10.1111/j.1474-919x.2004.00295.x/abstract)

      There is a handy animation from NASA, where they demonstrate how a model glider could fly like an albatross over the sea: http://youtu.be/F4zEaYl01Uw

      The publication of Sukumar and Selig talks about the possibility of Dynamic Soaring over open fields. This paper can open new possibilities for energy harvesting gliders, other than Jet Streams and orographic updrafts. They use a point-mass sailplane model for the computations and a piloted flight simulator. Their results prove that “it is possible to perform dynamic soaring in high wind conditions through the full extent of the atmospheric boundary layer to high altitudes over open land with model-scale unpowered sailplanes having both high wing loadings and high lift-to-drag ratios”. Dave, this is something that you would like to see, isn't it?

      http://www.learningace.com/doc/3049976/69855bf800eb437a074df03c7417a7bf/sukumarselig-2010-aiaa-2010-4953-ds-openfields

      At last, I would like to cite a proof that “These maneuvers can be accomplished today by means of full size gliders, and it is confirmed that a positive energy balance can be produced.” One of the first pilots who executed this task is Randel J. Gordon, Captain, USAF. Quotation from his MS Thesisii:

      The primary goal of this research was to prove or disprove the viability of dynamic soaring for enhancing a full size aircraft's total energy by using a manned sailplane as a demonstration air vehicle. Through modeling and simulation, flight test, and mathematical analysis, this research provided the first documented proof of the energy benefits realized using dynamic soaring techniques in full size sailplanes.”

      OPTIMAL DYNAMIC SOARING FOR FULL SIZE SAILPLANES (Manned Sailplane Dynamic Soaring) Thesis Presented to the Faculty Department of Aeronautical and Astronautical Engineering Graduate School of Engineering and Management Air Force Institute of Technology Air University AFIT/GAE/ENY06-S04 GAE 06S Author(s): Randel J. Gordon, Captain, USAF

      Some years ago, Capt. Gordon published a very interesting video titled : “Raptor force”, showing the flight of the sailing bird raptor as well as his own flight mentioned above at the same place. It is unfortunately not available anymore on the net (or I simply couldn't find it). Perhaps we ought to ask Capt Gordon whether this video is public or not?

      Lift!

      Gabor

      PS: Dave, as I have promised above, these are the concrete answers to your concrete question:

      1.) The following link is probably dealing with the exact same problem you have asked about:

      S.C. Beeler, D.D. Moerder and D.E. Cox: DYNAMIC SOARING OF SMALL GLIDER IN AN AMBIENT WIND GRADIENT. NIA Report No. 2004-05

      2.) The full answer is: Yes, but not by me, or rather... though I am not a flight-expert, I wrote a simple (or probably, the simplest possible) computer simulation on Dynamic Soaring some years ago. Applying it to some videos of model glider flight downloaded from the net, it was more than surprising to find them matching.






    • Joe Faust
      Here is a short from the apparent longer video: Raptor forcehttp://www.iptv.org/video/detail.cfm/1560/naat_20070213_natures_top _gun
      Message 2 of 25 , Jun 13, 2013
        Here is a short from the apparent longer video:
        Raptor force

        -------------------clip:   http://www.pbs.org/wnet/nature/episodes/raptor-force/introduction/1109/  where more than the clip is found.

        ======clip:

        Raptor Force
        Introduction

        NATURE takes flight on an exhilarating ride with elite winged predators in Raptor Force.

        Humans have had a unique relationship with raptors, nature's aerial killing machines, for more than four thousand years, first through the ancient sport of falconry, and, more recently, as scientists and engineers have turned to these mighty birds — from golden eagles, red-tailed hawks, and turkey vultures, to great gray owls and the peregrine falcon — as the inspiration for the latest in aircraft design. Using the tricks and tactics of raptors as their model, engineers have devised fighter jets with unprecedented maneuverability and stealth.

        In Raptor Force, you'll learn the secrets of these astonishing aerialists, and how they've mastered, more than any other type of bird, the art of soaring. And with the help of engineer and falconer Rob MacIntyre's ingenious miniature television station — a camera, transmitter, and battery small enough to be harnessed onto the backs of raptors — you'll see for yourself what it's like to fly with these deadly aces.

        Online content for Raptor Force was originally posted February 2007.

        To order a copy of Raptor Force, please visit the NATURE Shop.

        =================end of clip

      • Joe Faust
        Found full 54 min version of Raptor Force : http://www.youtube.com/watch?v=-3pa53GF8iA
        Message 3 of 25 , Jun 13, 2013
        • dave santos
          Hi Gabor,   Some of us have long discussed energy harvesting gliders (tetherless gliders with turbines) in our small circles, including the early AWES
          Message 4 of 25 , Jun 13, 2013
            Hi Gabor,
             
            Some of us have long discussed "energy harvesting gliders" (tetherless gliders with turbines) in our small circles, including the early AWES Forum.
             
            The modern motorglider with the pop-up propeller has been presumed as a probable standard configuration for at least two decades. Its been understood that this particular AWE concept vitally depends on strong upward convection, either by wind-driven slope-lift or a high atmospheric lapse rate. Convective cloud cores have been identified as a ready source of lift without mountains and prevailing winds ("cloud suck"). Robotic gliders could soon enough be able to operate inside of clouds and tolerate most lightning conditions. Operating over water or with parachutes can mitigate crash risks. Small flying models could validate almost all the known ideas.
             
            The main engineering question is what energy storage method is most economic, with high power-to-weight performance. We have speculated about exotic concepts like super-capacitor airframes to do "touch-and-go" discharge, or even hydrogen slush production, but without conclusive findings. Plain liquid-air as a product may be your novel contribution to the discussions.
             
            The high capital cost of high-performance gliders is another problem to resolve. Energy harvesting gliders may work well, but be  far too expensive to be profitable, compared to other means. Tethers are a cheap means of kinetic energy transfer, so we focus on them.
             
            Most of us do not depend on patents, but think open-source technology well-enough favors the most adept practitioners to be successful. There is no blocking IP we know of. We reserve CC moral rights which "good-actors" respect (The "Honor System"). We propose to share credit and profits on a peer basis. Others reject this model, but their hidden ideas tend to wither in isolation.
             
            Welcome to the AWES Forum, and congratulations on your interesting studies,
            daveS
          • dobosg001
            ... Hi Dave, Thank you for your very interesting mail. Formerly, I have discussed the challenge with a Hungarian company, a producer of small planes. They
            Message 5 of 25 , Jun 16, 2013
              --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
              >
              > Hi Gabor,
              >  
              > Some of us have long discussed "energy harvesting gliders" (tetherless gliders with turbines) in our small circles, including the early AWES Forum.
              >  
              > The modern motorglider with the pop-up propeller has been presumed as a probable standard configuration for at least two decades. Its been understood that this particular AWE concept vitally depends on strong upward convection, either by wind-driven slope-lift or a high atmospheric lapse rate. Convective cloud cores have been identified as a ready source of lift without mountains and prevailing winds ("cloud suck"). Robotic gliders could soon enough be able to operate inside of clouds and tolerate most lightning conditions. Operating over water or with parachutes can mitigate crash risks. Small flying models could validate almost all the known ideas.
              >  
              > The main engineering question is what energy storage method is most economic, with high power-to-weight performance. We have speculated about exotic concepts like super-capacitor airframes to do "touch-and-go" discharge, or even hydrogen slush production, but without conclusive findings. Plain liquid-air as a product may be your novel contribution to the discussions.
              >  
              > The high capital cost of high-performance gliders is another problem to resolve. Energy harvesting gliders may work well, but be  far too expensive to be profitable, compared to other means. Tethers are a cheap means of kinetic energy transfer, so we focus on them.
              >  
              > Most of us do not depend on patents, but think open-source technology well-enough favors the most adept practitioners to be successful. There is no blocking IP we know of. We reserve CC moral rights which "good-actors" respect (The "Honor System"). We propose to share credit and profits on a peer basis. Others reject this model, but their hidden ideas tend to wither in isolation.
              >  
              > Welcome to the AWES Forum, and congratulations on your interesting studies,
              > daveS
              >
              Hi Dave,

              Thank you for your very interesting mail.

              Formerly, I have discussed the challenge with a Hungarian company, a producer of small planes. They have mentioned almost the same difficulties as you, and they also would accept the task of overcoming them. At the same time, their price-offer seemed to be acceptable, - if I had enough money :-) . Also, I discussed other details with other experts. Applying these data and those mined from the literature we made a preliminary study on technical as well as economic feasibility, calculating data like investment costs, income/revenue, cash-flow plan, payback period, manufacturing costs, costs of maintenance, etc. The comparison with conventional WPPs was favorable to our „IFO" (= Identified Flying Object, the name of our energy harvesting gliders) in almost all respects. Therefore, I am sure that I prefer an Untethered Flying Wind Power Plant not because of „wishful thinking".

              Of course I know, the implementation would be not a simple task. It have to be a multidisciplinary project with contribution of experts of several professions. I think, I do neither overemphasize the problems nor underestimate the R&D work needed to implement a 20 MW net output power pilot plant by saying it to be about 4-6 years.

              As we know, the airspeed of the DS-ing plane is a multitude (about 6-10 times) of the windspeed gradient that it utilizes. Since the propeller power depends on the 3rd power of wind velocy, a prop mounted on a DS-ing glider is capable of producing 216 – 1000 times greater power than a NOT DS-ing (e.g.: tethered) one. This effect makes untethered flying WPPs much more favorable than the conventional WPPs. The above mentioned proportion of the sizes is like a car and a toy-car. This difference in sizes also significantly alters the investment costs. The smaller size of our gliders allows the application of more expensive materials. But I don't think that the construction materials of a glider would cost 200-1000 times more than that of a conventional WPP. On the contrary! A 100 m (or even larger) diameter rotor of a conventional WPP is made of the same or similar composite materials as a sophisticated glider of today.

              Obviously, tethered devices are not floating above one place but also are moving around the place of tethering. In what extent can tethered devices capitalized on the above mentioned beneficial effect of DS-ing by this movement?

              You are right, energy storage and forwarding it to the ground is really a cardinal question. I already wrote about this topic in this forum. (Energy-Harvesting Gliders #9364) The importance and the size of this topic probably needs a separate discussion, - if there isn't one already. What about starting this discussion with your current mail and my answer? If so, I am going to continue with some irregular thughts on the topic.

              At last, your IP model seems to be very interesting. Will you please inform me in detail? Who can participate? Are there any formalities (registration, etc.)? How do you protect your creative ideas against those who do not participate in the system, but use your inventions without any compensation, etc. ?

              Just a notice to the last topic. Perhaps you know that we Hungarians have had the „opportunity" to try communism. It did not work....

              Thank you for your kind welcome-words, and best regards,

              Gábor
            • dave santos
              Thanks, Gabor, for your thoughts.   Did the experts you consulted account for the following negative factors?   - cheap market energy - poor reliability of
              Message 6 of 25 , Jun 16, 2013
                Thanks, Gabor, for your thoughts.
                 
                Did the experts you consulted account for the following negative factors?
                 
                - cheap market energy
                - poor reliability of autonomous aircraft
                - high capital cost of aerospace platforms
                - safety liability, insurance cost, and cost of regulatory compliance
                - critical load-limit cases of extreme DS
                 
                Why no small cheap proof-of-concept flying model? This is both the earliest validation of tetherless AWE, and the critical-path to scaling up.
                 
                Our new IP model is simply fairness to creators via social media according to civilized norms. The formal basis is Moral Rights under international treaty law (Berne Convention).
                 
                Re: "Hungarian Communism": My political education defined this era as Stalinism (an instance of Fascist Totalitarianism) in the guise of Communism. Under Stalinism, subjects were indoctrinated to call it "Communism". This predicts your legacy usage of the term. Closer technical examples of Marxist-Leninist Communism are the US Military and elite socialist welfare states like North Europe and Japan. I advocate non-Marxist (non-materialist, non-macroeconomic) Communism like family and friends :)
                 
                daveS
                 
                 
                PS Everybody is reminded cut off previous messages in replies; especially to keep "daily digest" compilations compact; also to help conserve bandwidth and server space. Referencing selected quotes is good form.
              • dobosg001
                Dave, Thank you for the objective critique and the questions. I highly appreciate it, because until now I haven t received a lot of unbiased opinions. Please
                Message 7 of 25 , Jun 19, 2013
                  Dave,
                  Thank you for the objective critique and the questions. I highly appreciate it, because until now I haven't received a lot of unbiased opinions. Please find my remarks as follows:
                  First of all, I would like to repeat that I think the crucial factor in the competition between tethered and untethered energy harvesting devices is probably the fact that the airspeed of untethered DSing gliders is much higher than that of the prevailing wind or rather, the wind speed gradient. This way, the size of an IFO may be much smaller than that of other devices capable of producing the same power from the wind. Therefore, the price of the devices can be balanced. What about that?
                  Regarding energy prices, answering the question of what our project has to be compared with was not a simple task. Renewable energy is a lucrative business around the world. Numerous bodies, research institutes, government institutions and private organizations make assessments and forecasts concerning the future and profitability of this industry. Different people interpret the results and failures differently. The available data show great discrepancy depending on the source, and the evaluations are even more contradictory. In some cases, no agreement could be reached even on what is considered a failure or a success. Thus, there are serious questions and doubts concerning the economic rationale of traditional wind power plants. According to the Hungarian Ministry of National Development, the profitability of these power plants is questionable without government subsidy. This is presumably the reason for the Hungarian compulsory purchase system of wind-electricity (KÁT) and the high purchase price, which is criticized by several experts. As far as I know, there is another system in the United States. Accordingly, wind power plants are authorized for 2.1 cent/kWh production tax credit (PTC). It is clear, then, that wind energy holds the support of many governments, which would presumably not be the case, had these governments no good reasons for doing so.

                  Because of these circumstances, it is not obvious which energy price has to be applied. On the one hand, it would be unwise to forgo easily obtainable government support and with it the faster pay off.Fortunately, we have a very experienced innovation adviser who said that "on the other hand", we must be aware of what technology is capable of and not forget that government subsidies may be modified,even canceled. We accepted his opinion, according to which we must calculate with half the lowest energy-price, if we want to enter the market. In 2011, this was about 0,025 $/kWh. Calculating with such low electricity-price, the pay off time is 15.3 years, an almost acceptable value. Under the same conditions, the pay off time of the reference (conventional) wind power plant is 74 (!) years. This means an outstanding competitiveness even with such a low electricity price.

                  The capital costs depend first of all on the manufacturer of the sophisticated components,since one has to pay for his knowledge (super profit). There is a commonly accepted price level of e.g. gliders, which contains this mentioned high profit. But it mainly pertains to small series. If we are going to need a significant number of gliders, it depends on our decision whether we will buy gliders one after another, or if we buy a small but experienced factory where we organize a serial production to fulfill our demand. This way, the high profit remains with us. Dare to dream great! (It costs the same as a small dream...   :p )

                  Safety, liability and insurance hang together. Our gliders are in the "unusual" or "unknown" category today. That is, the high costs of insurance today are because of subjective reasons. But military and continously rising civil applications diffuse these aversions. Of course, further technical development is also needed to enhance liability and safety. These developments are in progress in several companies and university- or academic research teams. But today, it is already possible to build systems from "off-the-shelf" components, possessing high-reliability by applying enough (e.g.: triple) redundancy. If the contact goes off the air with the ground station because of any reason, then an inbuilt algorithm will take over the control, ensuring the return of the planes to the base without any outside control. These systems tend to belong to the commercial category. By the way, this is also a problem today in the case of tethered devices working in high altitude. As far as I know, they have to work in an area restricted from air traffic. Presumably, this will be not the case with untethered flying devices. These are like other airplanes.

                  You have seen above that I do not hesitate to calculate with a very low price of energy, if rational arguments (e.g.: the investigation of the market) show that this low price is needed to enter the market as an outsider, as a new participant of this play. But I do not hesitate also NOT to accept a price being a result of a hysteria and ignorance, -if a realistic approach shows just the very opposite. By the way, we are not alone having this problem. UAV-industryis growing up very rapidly. I am convinced that this problem will be no more a problem when our IFOs will start to fly.

                  Why no small cheap proof-of-concept flying model?  Wea re going to do even now some experiments with a model glider. But to tell the truth, I never ask "why NO?" , but "Why?". In this case the main motivation is the stress implied in yours and others question, - besides I like playing with a model plane. (I think, most of the results of this flight are foreseeable.)

                  Dave,I have never thought that there will come a time when somebody from the "West" will take the side of communism against me. Well, I say that the simplified stereotypic thoughts of the cold war about "our" communism have to be forgotten. Indoctrination proceeded both sides! In fact the fall of the totalitarian Stalinism in Hungary proceeded a lot of time before the fall of the whole system. After the '70s, the "dictatorship" in Hungary could not be called a "totalitarian Stalinistic dictatorship". It was something of a benevolent and viable system, ensuring much higher social safety than today. The price of it was a lower standard of living and the predominance of collective rights(e.g.: right to work, -there was no unemployment!) instead of personal rights (e.g.:free-enterprise). Being "gray", that is, not rising above the crowd was more rewarding than doing so. And this was the reason why the system fell. It was not competitive, it did not motivate people to do their best.And this is what I'm talking about when I say that communism did not work for us. Well, I like the communism that you imagine. But I am afraid that it cannot be realized outside of one's family. (Perhaps without any people...  :) )

                  Lift!

                  Gabor

                  PS.: I hope, the formal criteria of my script is already OK. If not, I ask your kind help by noticing it in a private message. Thanks!

                • Bob Stuart
                  I don t think you will find unusually high profits in the aircraft industry. One reason for the high cost of flight is that it is estimated that the weight of
                  Message 8 of 25 , Jun 19, 2013
                    I don't think you will find unusually high profits in the aircraft industry.  One reason for the high cost of flight is that it is estimated that the weight of a certified aircraft is the same as the weight of the papers documenting its construction.  While high-speed flight does good things for energy density, getting us back to the territory made familiar by internal combustion, it also requires very expensive, lightweight construction techniques.  It is tempting to use conventional approaches to wind power engineering, but it is a very different problem.  Efficiency is not achieved by extracting most of the energy from a small volume of air, as if it were expensive fuel, but by accessing as much air as possible, at an acceptable efficiency.  

                    A rough rule of thumb is that enclosed space in a boat costs ten times as much as in a building on land, and in an aircraft, it is up another order of magnitude.  For decades, people tried to win the Kremer prize by using advanced glider technology.  It was finally won by the "old fashioned" trick of using guy wires.  Their parasitic drag was worth it for the reduction in weight for the wing area.  Similarly, the drag of kite lines is found acceptable for parafoil speeds.  

                    Bob Stuart

                    On 19-Jun-13, at 8:13 AM, dobosg001 wrote:


                    The capital costs depend first of all on the manufacturer of the sophisticated components,since one has to pay for his knowledge (super profit). There is a commonly accepted price level of e.g. gliders, which contains this mentioned high profit. But it mainly pertains to small series. If we are going to need a significant number of gliders, it depends on our decision whether we will buy gliders one after another, or if we buy a small but experienced factory 
                    where we organize a serial production to fulfill our demand. This way, the high profit remains with us. Dare to dream great! (It costs the same as a small dream...   :p )

                  • Joe Faust
                    http://energykitesystems.net/0/FFAWE/untethered.jpg http://energykitesystems.net/0/FFAWE/WO2010106382A2GaborDobos.pdfPDF of the patent application before
                    Message 9 of 25 , Jul 14, 2013
                      http://energykitesystems.net/0/FFAWE/untethered.jpg
                      http://energykitesystems.net/0/FFAWE/WO2010106382A2GaborDobos.pdf
                      PDF of the patent application before incomplete international search was made:  HERE 

                      I keep studying the patent application and keep finding no inventive leap in the teaching.  Gabor tells me that he has inventive leap described in his disclosure, perhaps in some combination of things.  Yet, the literature seems to show that all of the involved energy making, storing, transferring, dynamic soaring, wind wheels onboard, etc. has been covered in prior studies and disclosures.    I stay tuned to anyone's explanations. What is obvious to those skilled in the attending arts may not be obvious to those not skilled in the attending arts.  Soar a RAT equipped glider, store some energy gained, use some energy gained in the glider system, and send some energy gained to objects apart from the glider.    Of course, humans have not fully exploited such method; the future will explore niche uses of the involved methods for inhabited and uninhabited aircraft.  Various degrees of autopilot will be used.    It will be interesting to see if some inventive leap will hold in the IFO stream. It would be a joy to realized an inventive leap.   Even if not, the focus on mining soaring is a fun party. 

                      Soaring with one wing is one thing.   It is fun to contrast the free-flight two-wing kite system that dynamically soars using two differently characterized portions of the atmosphere, but without having any tether to the ground, but with have a coupling tether between the dynamically soaring separated wings. 

                      ~JpF
                            

                       

                    • Bob Stuart
                      It is quite a leap, to go from expensive aircraft that require fuel, to even more expensive ones that can stay up for a while without fuel, to inexpensive ones
                      Message 10 of 25 , Jul 14, 2013
                        It is quite a leap, to go from expensive aircraft that require fuel, to even more expensive ones that can stay up for a while without fuel, to inexpensive ones that land with far more "fuel" than they took off with.  However, there could be a fine chance for the sporting flier to indulge in competitions while actually at work.  Maybe it should be straight commission work, since even ag flying gets tedious.  Going along for the ride would hurt performance, but might offer other advantages for a while.  

                        Bob Stuart

                        On 14-Jul-13, at 8:45 PM, Joe Faust wrote:


                        I keep studying the patent application and keep finding no inventive leap in the teaching.  Gabor tells me that he has inventive leap described in his disclosure, perhaps in some combination of things.  Yet, the literature seems to show that all of the involved energy making, storing, transferring, dynamic soaring, wind wheels onboard, etc. has been covered in prior studies and disclosures.    I stay tuned to anyone's explanations. What is obvious to those skilled in the attending arts may not be obvious to those not skilled in the attending arts.  Soar a RAT equipped glider, store some energy gained, use some energy gained in the glider system, and send some energy gained to objects apart from the glider.    Of course, humans have not fully exploited such method; the future will explore niche uses of the involved methods for inhabited and uninhabited aircraft.  Various degrees of autopilot will be used.    It will be interesting to see if some inventive leap will hold in the IFO stream. It would be a joy to realized an inventive leap.   Even if not, the focus on mining soaring is a fun party. 

                        Soaring with one wing is one thing.   It is fun to contrast the free-flight two-wing kite system that dynamically soars using two differently characterized portions of the atmosphere, but without having any tether to the ground, but with have a coupling tether between the dynamically soarin g separated wings. 

                        ~JpF
                              

                         

                      • David Lang
                        Bob, Good string of analogies! The question remains whether the process of un-tethered dynamic soaring is an energy-robust cycle, when constrained to an
                        Message 11 of 25 , Jul 14, 2013
                          Bob,

                          Good string of analogies!

                          The question remains whether the process of un-tethered dynamic soaring is an energy-robust cycle, when constrained to an "average no net altitude or positional drift". My guess is, that  until a time domain simulation (or, say, an early-on piloted example) of this process is demonstrated such that said demonstration reflects the deleterious disturbing effects on trajectory of the actual on-board energy harvesting device, this scheme is highly conjectural. Lest I be accused of singling out this scheme for criticism, the same can be said of many of the schemes being bandied about on this forum. However, this scheme does set the flag to raise the question "once the tether is abandoned, then what besides wind gradient and gravity serves to effectively hold this flying device into the "teeth of wind"?

                          DaveL




                          On Jul 14, 2013, at 8:10 PM, Bob Stuart <bobstuart@...> wrote:

                           

                          It is quite a leap, to go from expensive aircraft that require fuel, to even more expensive ones that can stay up for a while without fuel, to inexpensive ones that land with far more "fuel" than they took off with.  However, there could be a fine chance for the sporting flier to indulge in competitions while actually at work.  Maybe it should be straight commission work, since even ag flying gets tedious.  Going along for the ride would hurt performance, but might offer other advantages for a while.  


                          Bob Stuart

                          On 14-Jul-13, at 8:45 PM, Joe Faust wrote:


                          I keep studying the patent application and keep finding no inventive leap in the teaching.  Gabor tells me that he has inventive leap described in his disclosure, perhaps in some combination of things.  Yet, the literature seems to show that all of the involved energy making, storing, transferring, dynamic soaring, wind wheels onboard, etc. has been covered in prior studies and disclosures.    I stay tuned to anyone's explanations. What is obvious to those skilled in the attending arts may not be obvious to those not skilled in the attending arts.  Soar a RAT equipped glider, store some energy gained, use some energy gained in the glider system, and send some energy gained to objects apart from the glider.    Of course, humans have not fully exploited such method; the future will explore niche uses of the involved methods for inhabited and uninhabited aircraft.  Various degrees of autopilot will be used.    It will be interesting to see if some inventive leap will hold in the IFO stream. It would be a joy to realized an inventive leap.   Even if not, the focus on mining soaring is a fun party. 

                          Soaring with one wing is one thing.   It is fun to contrast the free-flight two-wing kite system that dynamically soars using two differently characterized portions of the atmosphere, but without having any tether to the ground, but with have a coupling tether between the dynamically soarin g separated wings. 

                          ~JpF
                                

                           



                        • Gabor Dobos
                          Hallo Friends, I enjoy reading your comments. I will answer soon, but because of my linguistic difficulties I ask your patience. Gábor ... Hallo Friends, I
                          Message 12 of 25 , Jul 15, 2013
                            Hallo Friends,
                            I enjoy reading your comments. I will answer soon, but because of my linguistic difficulties I ask your   patience.
                            Gábor

                            On 2013-07-15 05:49, David Lang wrote:
                             


                            On Jul 14, 2013, at 8:10 PM, Bob Stuart <bobstuart@...> wrote:


                            On 14-Jul-13, at 8:45 PM, Joe Faust wrote:


                             




                          • Gabor Dobos
                            ... DaveL, You ought to discusss with JoeF, since his opinion is at the other extreme by saying that all my ideas have been well known almost since the
                            Message 13 of 25 , Jul 27, 2013
                              On 2013-07-15 05:49, David Lang wrote:
                              The question remains whether the process of un-tethered dynamic soaring is an energy-robust cycle, when constrained to an "average no net altitude or positional drift". My guess is, that  until a time domain simulation (or, say, an early-on piloted example) of this process is demonstrated such that said demonstration reflects the deleterious disturbing effects on trajectory of the actual on-board energy harvesting device, this scheme is highly conjectural. Lest I be accused of singling out this scheme for criticism, the same can be said of many of the schemes being bandied about on this forum. However, this scheme does set the flag to raise the question "once the tether is abandoned, then what besides wind gradient and gravity serves to effectively hold this flying device into the "teeth of wind"?

                              DaveL


                              DaveL,
                              You ought to discusss with JoeF, since his opinion is at the other extreme by saying that all my ideas have been  well known almost since the beginning of time... -:) Excuse me, but I don't know what to think upon reading your comment above. To tell the truth, I do not think that you don't know the answers.  Are  your questions  perhaps jokes just to test me?  If so, I mustn't even believe what you're asking... -:)

                              The idea isn't conjectural. It is based on facts and technical evidence e.g.:

                              • piloted example:

                              "The demonstrator’s rotors are driven by advanced electric motors powered by rechargeable batteries
                              The demonstrator’s rotors when on the ground can be tilted forward and the aircraft pointed into wind to allow the rotors to windmill and recharge the aircraft’s electrical storage device."
                              See more::
                               http://www.agustawestland.com/news/agustawestland-unveils-project-zero-tilt-rotor-technology-demonstrator    
                              There are a lot of findings with motorgliders. The " disturbing effects "of the prop.  entail nothing unusual. These can be calculated, see JoeF's  comments about RATs
                              • what holds this flying device into the "teeth of wind"?                                                                                                         
                              Apart from wind gradient and gravity, the inertial mass

                              • energy-robust cycle
                              Of course, simulations are seeking a borderline case, to show the best or worse case. But in a practical case the practical question is not that,  The question is whether the device is capable of withstanding the huge energy density of the Jet.  We have to worry about whether we get back the glider as a glider or a dump of  debris   and not of that energy-neutral trajectory.    



                              Wing-test of a model-glider


                              Gabor

                            • David Lang
                              Gabor, I assure you that my question is sincere; While I may have intuitive opinions (not addressed in this response) regarding the answer to this question, I
                              Message 14 of 25 , Jul 28, 2013
                                Gabor, 

                                I assure you that my question is sincere; While I may have intuitive opinions (not addressed in this response) regarding the answer to this question, I do not in fact know the answer.

                                I do not question the fact that endless free-soaring can be accomplished (JoeF, et al, certainly quote examples pertaining to this possibility). A seagull executing "boundary layer soaring" being a good example of such a process.

                                But let me explain more fully what I question. I will start by loosely defining a "free-flying energy cycle" as a type of repetitive maneuver that harvests energy, 

                                some of which
                                1. is used by the process itself to maintain an average position in space (ie. so as not to progressively loose altitude, or be swept down-stream like a boat in a river), 

                                and the remainder of which
                                2. is somehow stored on-board or directed earthward for practical use (net energy harvest)

                                Given the above preface, I would further define a "robust energy cycle" as one for which the "net energy harvest" is of sufficient magnitude to result in a competitive "Cost of Energy" (COE) and an attractive "Return on Investment" (ROI); in the current world energy market, largely driven by fossil fuel COE, it is my opinion that AWE must compete on the economic level to be accepted.

                                So the question is, what do you (or anyone) know about the net energy harvest of your invention? The same can be said for many of the proposed inventions that appear on this forum, so I would point out that this is not just a critique specific to your idea.

                                I further claim that since your invention :

                                A. involves a constantly changing dynamic flight profile in reaction to the varied winds (ie more specifically, the wind gradients) 
                                and 
                                B. must conduct maneuvers so as to avoid being swept evermore down-wind away from harvesting-station facilities, 

                                that a time-domain simulation of the method engaged in an energy harvesting maneuver in a "nominal design wind environment" is required in order to arrive at a believable assessment of the expected "net energy harvest" (ie. an assessment of how "robust" the energy cycle actually is).

                                Gabor, based on my long experience in the aerospace business, I strongly disagree with your following statement: 

                                "Of course, simulations are seeking a borderline case, to show the best or worse case. But in a practical case the practical question is not that…".  

                                I claim that traditionally in aerospace engineering, while simulation is indeed useful in exploring extreme and borderline situations (without risk of losing the vehicle by actual flight experimentation) it is first used to simply demonstrate the potential for successful nominal flight (energy harvest in your case)….this is what I contend is missing in your conjectures and is needed to convince investors that the method deserves actual development toward flight testingspecific .

                                Hope this clarifies my question.

                                Regards

                                DaveL


                                On Jul 27, 2013, at 5:26 PM, Gabor Dobos <dobosg001@...> wrote:

                                On 2013-07-15 05:49, David Lang wrote:
                                The question remains whether the process of un-tethered dynamic soaring is an energy-robust cycle, when constrained to an "average no net altitude or positional drift". My guess is, that  until a time domain simulation (or, say, an early-on piloted example) of this process is demonstrated such that said demonstration reflects the deleterious disturbing effects on trajectory of the actual on-board energy harvesting device, this scheme is highly conjectural. Lest I be accused of singling out this scheme for criticism, the same can be said of many of the schemes being bandied about on this forum. However, this scheme does set the flag to raise the question "once the tether is abandoned, then what besides wind gradient and gravity serves to effectively hold this flying device into the "teeth of wind"?

                                DaveL


                                DaveL,
                                You ought to discusss with JoeF, since his opinion is at the other extreme by saying that all my ideas have been  well known almost since the beginning of time... -:) Excuse me, but I don't know what to think upon reading your comment above. To tell the truth, I do not think that you don't know the answers.  Are  your questions  perhaps jokes just to test me?  If so, I mustn't even believe what you're asking... -:)

                                The idea isn't conjectural. It is based on facts and technical evidence e.g.:

                                • piloted example:

                                "The demonstrator’s rotors are driven by advanced electric motors powered by rechargeable batteries
                                The demonstrator’s rotors when on the ground can be tilted forward and the aircraft pointed into wind to allow the rotors to windmill and recharge the aircraft’s electrical storage device."
                                See more::
                                 http://www.agustawestland.com/news/agustawestland-unveils-project-zero-tilt-rotor-technology-demonstrator    
                                There are a lot of findings with motorgliders. The " disturbing effects "of the prop.  entail nothing unusual. These can be calculated, see JoeF's  comments about RATs
                                • what holds this flying device into the "teeth of wind"?                                                                                                         
                                Apart from wind gradient and gravity, the inertial mass

                                • energy-robust cycle
                                Of course, simulations are seeking a borderline case, to show the best or worse case. But in a practical case the practical question is not that,  The question is whether the device is capable of withstanding the huge energy density of the Jet.  We have to worry about whether we get back the glider as a glider or a dump of  debris   and not of that energy-neutral trajectory.    

                                <gifiagac.png>

                                Wing-test of a model-glider


                                Gabor


                              • Joe Faust
                                ... * This note does not handle all the good points presented for discussion, but I address momentarily only an alternative scenario that has been mentioned
                                Message 15 of 25 , Jul 28, 2013
                                  Re:   On Sun, Jul 28, 2013 at 10:48 AM, David Lang <SeattleDL@...> wrote:
                                  some of which
                                  1. is used by the process itself to maintain an average position in space (ie. so as not to progressively loose altitude, or be swept down-stream like a boat in a river), 


                                  No-tether-to-ground: Allow downwind sweep case
                                    This note does not handle all the good points presented for discussion, but I address momentarily only an alternative scenario that has been mentioned in forum at some point.   This note regards a free-flying AWES that is allowed to drift regularly downwind and not try to stay positioned for any specific fixed ground station.  For example, let a RAT-embedded dynamically-soaring sailplane enter the edges of a jet stream to harvest energy in the gradients; but let the sailplane travel regularly eastward  in the general direction of the jet stream of the example.  Have earth-surround ground receivers continually available; that is, soon another ground station receiver will be available for dumping harvested energy products.   Do not expend aloft energy to stay over, say, Kansas, but allow the AWES to have a ground trace around the world again and again.    This scenario would then not expend energy "to maintain" any average position in space as regards the being swept down stream.  However, there would still be the expenditure of some energy for maintaining altitude of the craft.     This scenario might be termed: Allow downwind sweep case.  
                                • dave santos
                                  DaveL, Gabor, The obvious early niche solution for keeping-place in AWE soaring is to locate in slope and thermal updrafts. If the glide speed exceeds the
                                  Message 16 of 25 , Jul 28, 2013
                                    DaveL, Gabor,

                                    The obvious early niche solution for keeping-place in AWE soaring is to locate in slope and thermal updrafts. If the glide speed exceeds the horizontal wind speed, and the sink rate is less than upward flow rate, then flight is sustainable, with any reserve capacity available to generate power. By merely assuming world-class up-drafts, one can confidently find that an energy-robust cycle is plausible, without needing difficult arguments from non-existent data.

                                    Interestingly, a SLACK conductive-tether might be effective to transfer energy from the sort of heroic updrafts Gaddis experienced paragliding in the Himalayas, with 70mph updrafts in proximity to remote mountain populations. This instance alone might falsify the notion that all tethers are inferior compared to, say, aviation-qualified liquid-air generation. Ordinary "cloud-suck" under common cumulus is not so energetic, but is very common world-wide, and could be the initial basis for an FF AWE industry. Often thermals abound in low-wind, even in zero "prevailing-wind".

                                    Unlimited DSing for utility-scale energy, as Gabor proposes, faces a long critical-path. JoeF naturally takes the long view, but DaveL is also quite right to question the current feasibility. There is not even one small prototype yet, which is a key milestone for Gabor and his R&D circle to work toward before he can convince a larger circle. If progess is slow, Gabor at least be reassured that this concept has been long understood by a few theorists, that he is not crazy nor alone in seeing the potential.

                                    Here a fat stubby puffin shows how updraft-work  done, just imagine something like the AugustaWestland E-VTOL rotorcraft on the job- 

                                     

                                    daveS



                                  • David Lang
                                    JoeF, Your conjectures entail a lot of what if s regarding global wind state, plentiful energy-reception stations, etc. What I am getting at is much simpler
                                    Message 17 of 25 , Jul 28, 2013
                                      JoeF,

                                      Your conjectures entail a lot of "what if's" regarding global wind state, plentiful energy-reception stations, etc.

                                      What I am getting at is much simpler and (I think) to the point regarding tetherless glider energy harvesting in general. Suppose you took a boundary-soaring seagull, which has the ability to demonstrate the maintenance of "average position" by using wind gradient……now, add a little drogue-chute to its tail……how might it fair under the influence of that additional drag….could it muster enough additional energy harvest from the wind gradient to still maintain average position?

                                      My intuitive assessment of tetherless (ie. non-externally-equilibrated wind force) energy harvesting envisions that reverse-effective forces (ie. d'Alambert forces) are all you have
                                       at your disposal to "stand your ground against the wind" (ie. in order to force relative wind to persist at useful levels.....try harvesting energy in a uniform 200 kt jet stream with this scheme…..all you end up doing is being swept across the countryside),  equilibrating d'Alembert forces cannot exceed the product of your mass and acceleration; This is as opposed to other schemes that have an external "grip" on something, said external grip being: a "tether" (for most AWE schemes),   "keel/hull-drag" (for sailboats), "tires contacting ground-friction" (for a propeller driven vehicle that can move into the teeth of the wind", etc.

                                      If we intend to be serious purveyors of AWE, we must believably quantify the amount of energy we imply that we can harvest.

                                      DaveL



                                      On Jul 28, 2013, at 12:09 PM, Joe Faust <joefaust333@...> wrote:

                                      Re:   On Sun, Jul 28, 2013 at 10:48 AM, David Lang <SeattleDL@...> wrote:
                                      some of which
                                      1. is used by the process itself to maintain an average position in space (ie. so as not to progressively loose altitude, or be swept down-stream like a boat in a river), 


                                      No-tether-to-ground: Allow downwind sweep case
                                        This note does not handle all the good points presented for discussion, but I address momentarily only an alternative scenario that has been mentioned in forum at some point.   This note regards a free-flying AWES that is allowed to drift regularly downwind and not try to stay positioned for any specific fixed ground station.  For example, let a RAT-embedded dynamically-soaring sailplane enter the edges of a jet stream to harvest energy in the gradients; but let the sailplane travel regularly eastward  in the general direction of the jet stream of the example.  Have earth-surround ground receivers continually available; that is, soon another ground station receiver will be available for dumping harvested energy products.   Do not expend aloft energy to stay over, say, Kansas, but allow the AWES to have a ground trace around the world again and again.    This scenario would then not expend energy "to maintain" any average position in space as regards the being swept down stream.  However, there would still be the expenditure of some energy for maintaining altitude of the craft.     This scenario might be termed: Allow downwind sweep case.  

                                    • Bob Stuart
                                      I think we have to allow a downwind sweep to give these much chance at all. The Albatross is a champion of dynamic soaring, and it follows the annual winds,
                                      Message 18 of 25 , Jul 28, 2013
                                        I think we have to allow a downwind sweep to give these much chance at all.  The Albatross is a champion of dynamic soaring, and it follows the annual winds, at home anywhere, but at a fixed location on land only yearly.  

                                        I note that Paul MacCready was a champion soaring pilot, but when his company set out to build a station-keeping aircraft as a robotic tall antenna, they went with solar.

                                        While we are here, has anyone ever heard about an electric aircraft or helicopter being powered through a tether?  I'd be inclined to try high frequency AC through a single conductor, with a capacitor on board.  Combined with kiting, it might make a good way to keep an antenna up, at least.  With all that hardware in the air anyway, it could be a fly-gen with a ground battery bank, able to sustain itself in remote locations.  

                                        Bob Stuart

                                        On 28-Jul-13, at 1:58 PM, David Lang wrote:

                                        JoeF,


                                        Your conjectures entail a lot of "what if's" regarding global wind state, plentiful energy-reception stations, etc.

                                        What I am getting at is much simpler and (I think) to the point regarding tetherless glider energy harvesting in general. Suppose you took a boundary-soaring seagull, which has the ability to demonstrate the maintenance of "average position" by using wind gradient……now, add a little drogue-chute to its tail……how might it fair under the influence of that additional drag….could it muster enough additional energy harvest from the wind gradient to still maintain average position?

                                        My intuitive assessment of tetherless (ie. non-externally-equilibrated wind force) energy harvesting envisions that reverse-effective forces (ie. d'Alambert forces) are all you have
                                         at your disposal to "stand your ground against the wind" (ie. in order to force relative wind to persist at useful levels.....try harvesting energy in a uniform 200 kt jet stream with this scheme…..all you end up doing is being swept across the countryside),  equilibrating d'Alembert forces cannot exceed the product of your mass and acceleration; This is as opposed to other schemes that have an external "grip" on something, said external grip being: a "tether" (for most AWE schemes),   "keel/hull-drag" (for sailboats), "tires contacting ground-friction" (for a propeller driven vehicle that can move into the teeth of the wind", etc.

                                        If we intend to be serious purveyors of AWE, we must believably quantify the amount of energy we imply that we can harvest.

                                        DaveL



                                        On Jul 28, 2013, at 12:09 PM, Joe Faust <joefaust333@...> wrote:

                                        Re:   On Sun, Jul 28, 2013 at 10:48 AM, David Lang <SeattleDL@...> wrote:
                                        some of which
                                        1. is used by the process itself to maintain an average position in space (ie. so as not to progressively loose altitude, or be swept down-stream like a boat in a river), 


                                        No-tether-to-ground: Allow downwind sweep case
                                          This note does not handle all the good points presented for discussion, but I address momentarily only an alternative scenario that has been mentioned in forum at some point.   This note regards a free-flying AWES that is allowed to drift regularly downwind and not try to stay positioned for any specific fixed ground station.  For example, let a RAT-embedded dynamically-soaring sailplane enter the edges of a jet stream to harvest energy in the gradients; but let the sailplane travel regularly eastward  in the general direction of the jet stream of the example.  Have earth-surround ground receivers continually available; that is, soon another ground station receiver will be available for dumping harvested energy products.   Do not expend aloft energy to stay over, say, Kansas, but allow the AWES to have a ground trace around the world again and again.    This scenario would then not expend energy "to maintain" any average position in space as regards the being swept down stream.  However, there would still be the expenditure of some energy for maintaining altitude of the craft.     This scenario might be termed: Allow downwind sweep case.  



                                      • Gabor Dobos
                                        DaveL, Thank you very much for your sincere answer. I assure you that I highly appreciate your questions, statements and your willingness to discuss my
                                        Message 19 of 25 , Aug 4, 2013

                                          DaveL,

                                          Thank you very much
                                          for your "sincere" answer. I assure you that I highly appreciate your questions, statements and your willingness to discuss my ideas. But if your questions are not jokes in order to test me, than I have to assume that you have to failed to read some interesting details about dynamic soaring. Please, allow me to write my responses  in your text below. Perhaps this way it is simpler to follow them.

                                          Furthermore, upon reading the literature I see that there is a widely accepted consensus today that energy harvesting from the jet streams is possible through applying Dynamic Soaring.  More: see embedded into your text below.

                                          Though, that is a widely accepted opinion, in order to avoid being biased, I have to say that there is also a counter advice recently. According to researchers of the Max Planck Institute, the assumption that high wind speeds in the jet stream correspond with high wind power are incorrect. The actual extractable energy from the jet stream is 200 times less than has been previously reported.  It is of course bad news for the tethered devices too.
                                          http://www.energymatters.com.au/index.php?main_page=news_article&article_id=1932

                                          With friendship,

                                          Gabor




                                          On 2013-07-28 19:48, David Lang wrote:
                                          Gabor, 

                                          I assure you that my question is sincere; While I may have intuitive opinions (not addressed in this response) regarding the answer to this question, I do not in fact know the answer.

                                          I do not question the fact that endless free-soaring can be accomplished (JoeF, et al, certainly quote examples pertaining to this possibility). A seagull executing "boundary layer soaring" being a good example of such a process.

                                          But let me explain more fully what I question. I will start by loosely defining a "free-flying energy cycle" as a type of repetitive maneuver that harvests energy, 

                                          some of which
                                          1. is used by the process itself to maintain an average position in space (ie. so as not to progressively loose altitude, or be swept down-stream like a boat in a river), 

                                          and the remainder of which
                                          2. is somehow stored on-board or directed earthward for practical use (net energy harvest)

                                          Given the above preface, I would further define a "robust energy cycle" as one for which the "net energy harvest" is of sufficient magnitude to result in a competitive "Cost of Energy" (COE) and an attractive "Return on Investment" (ROI); in the current world energy market, largely driven by fossil fuel COE, it is my opinion that AWE must compete on the economic level to be accepted.
                                          You are right! The only problem is that you are criticizing a Viability Study, while you have a Patent Application in hand. These are two distinct kinds of documents and each has its own formal and content criteria. (By the way, I also wrote a Viability study, containing preliminary calculations on COE and ROI.)


                                          So the question is, what do you (or anyone) know about the net energy harvest of your invention? Oof cource. RATs are well known components. They can be calculated or sized. Furthermore there are a lot of findings with motorgliders, e.g. the drag of the prop is welll known. And there are already motorglidere which can haarvest energy from the wind like my IFOs. The only difference is that the much more larger energy density of the Jet Streams  would destroy these devices. It means that  the "net energy harvest" is limited today by the stability of the device.  That is, I can (and have) calculate with these limits.   The same can be said for many of the proposed inventions that appear on this forum, so I would point out that this is not just a critique specific to your idea. 

                                          I further claim that since your invention :

                                          A. involves a constantly changing dynamic flight profile in reaction to the varied winds (ie more specifically, the wind gradients) 
                                          and 
                                          B. must conduct maneuvers so as to avoid being swept evermore down-wind away from harvesting-station facilities, Excuse me DavidL, all of these doubts are unreasonable. Remember, dinamic soaring we have borrowed from soaring birds. These birds, like albattross are able to fly in any wind in any direction.  I propose to play a while with P. Barnes' handy simulation. You will see, if Dynamic Soaring is possible at al, then your problems are not problems. The link of the simulation I have sent you alreagy jjust for sake of simplicity: http://www.howfliesthealbatross.com (Find picture 2. on this site and follow instructions.) It is possible DS-ing against  the wind, ore to exploit the worst possible case namely downdrafts to gain altitude. e.g.: "Vector diagram of dynamic soaring: showing how a glider can get energy from a downward gust" by Taras Kiceniuk : http://www.icarusengineering.com/Vector-Diagram-Soaring-Sink.GIF

                                          The equations of motion of these birds are well known, and the simulation is also solved.

                                          e.g.: J.P. Barnes : How Flies the Albatross –The Flight mechanics of Dynamic Soaring. SAE Technical Papers No. : 2004-01-3088
                                          There is a distinct part of science, called "biomimethic behavioural engineering", dealing with writeing  remot control software and simulations, applying  "bird - inspired" decisions:

                                          Bioinsp. Biomim. 1 (2006) 76–88 doi:10.1088/1748-3182/1/3/002. Design of a bio-inspired controller for dynamic soaring in a simulated unmanned aerial vehicle. Renaud Barate, St´ephane Doncieux and Jean-Arcady Meyer, Universit´e Pierre et Marie Curie—Paris 6, UMR 7606, AnimatLab/LIP6, 8 rue du Capitaine Scott, Paris 75015, France

                                          that a time-domain simulation of the method engaged in an energy harvesting maneuver in a "nominal design wind environment" is required in order to arrive at a believable assessment of the expected "net energy harvest" (ie. an assessment of how "robust" the energy cycle actually is).  It seems so, you are an expert in this topic , aren't you? By any shance, have you an appropriate software?
                                          Atthe begining the question was whether it is possible dynamically soaring in the Jet Sreams, and especially  whether it is possible to fly long time at least an energy-neutral trajectory.   Since the flight mechanics of albatross was known at that time, also early simulations can be found in the literature. One of the first studies in this topic was   :
                                          Rais-Rohani, Mascud : A Feasibility Study of Dynamic Soaring in the Jet Stream. A Thesis Submitted to the Faculty of Mississippi State University, Mississippi State, Mississippi, USA  1985
                                          Well, I am not an expert in control technique, but I early noticed that  remote control and simulation needs sophisticated software, e.g. an early paper to the topic:
                                          D. Bernstein: Control Constrains, Abnormality, and Improved Performance by Periodic Control. - IEEE TRANSACTIONS ON AUTOMATIC CONTROL., VOL. AC-30, NO. 4, APRIL 1985  p 367-376
                                          There are today flight simulator softwares from toy to scientific category. It isn't a problem anymore to simulate DS-ing flight. Furthermore there are several companies who are ready to help you simulate test-flights whatever just you want.(If one have some money.) e.g.: http://www.micropilot.com/services-custom-development.htm

                                          Gabor, based on my long experience in the aerospace business, I strongly disagree with your following statement: 

                                          "Of course, simulations are seeking a borderline case, to show the best or worse case. But in a practical case the practical question is not that…".  

                                          I claim that traditionally in aerospace engineering, while simulation is indeed useful in exploring extreme and borderline situations (without risk of losing the vehicle by actual flight experimentation) it is first used to simply demonstrate the potential for successful nominal flight(energy harvest in your case)….this is what I contend is missing in your conjectures and is needed to convince investors that the method deserves actual development toward flight testingspecific .

                                          Hope this clarifies my question.

                                          Yes, indeed, and thanks for your patience.  (But I am afraid that you will need it yet.  :) I hope, a short  summary of my project-management strategy (based on my long experience  :-)  ) clarifies my point of view.

                                          I know the way intimatelly, what you are proposing. It is very appropriate for basic research.One choses usually  an unknown topic, studies it carefully, solves the problems and publishes the results. And than one chose the next most  interesting one from the reseach fied you are engaged in. And sometimes (in fact: almost always) an innner force oblige you to chose not only one but more, - since the list of NOT KNOWN  things is endless, and very interesting., Doing so maybe successful, if you are chargeable enough.

                                          But what was a good starting point for a basic researcher is totally wrong for an ""implementer. "
                                                                                                                                                       "                                                                                                                                                                                                                                                                          Since the list of NOT KNOWN  things is endless, we have to begin with summarizing WHAT WE KNOW and deciding NOT TO DO or rather not repeat the work that has already been done by others, or the result will be foreseeable.  Probably, it is more important to firmly  decide what NOT TO DO  than what TO DO,

                                          Having the list WHAT WE KNOW, we have to evaluate whether it is enough to implement the plan or not?

                                          If not, repeat from the previous step with determining the missing topic(s) and seeking/contacting another possible  contributors, who possesses the missing knowledge or skills.
                                           
                                          If yes, one has to follow further  the project management plan.

                                          I don't know if you are beginning to understand this strategy? While  in case of a large plan, there are of course several possibilities to make preliminary experiments or measurements, if I measure  forseeable data or repeat a known work (without any heavy reason),  it will be hard to say where to stop with. The leader of such plan have to be very  orderly in this aspect, -
                                          otherwise the implementation of a complex task turns into an enthusiastic goose step, and at the same time the costs will rise to the sky (Instead of our IFOs).

                                          Well, I doon't say that the simulation what you advise to do is unnecessary. If I had the appropriaite software on  my computer (and I would be familiar with it or had decided to becom to be) I would do it. But on the one hand  I think,  if I made this simulation,  I would have no more prove currently regarding my invention than without it.  Don't think that an investor will appreciate it.   On the other hand in the course of the implementation the professional parther who will deal with these tasks, surely will do this simulation, among others. But it will be his decision  and not mine. i (or rather the project leader ) will be obliged to make a decision if the things don't go ahead. In this case I have to say thank you and good bye, - without any hesitation.

                                           let us return to a question of DaveS (and a lot of others): „Why no small cheap proof-of-concept flying model? “  There are endless number of questions beginning with “Why not?"    These questions are  irrelevant   We have to know exactly WHY we DO something? Systhematic asking WHY  and answering it, results an experiment-plan of the project.

                                           In spite of the above "study" ,   we are going to do even now some experiments with a model glider.  In this case the main motivation is the stress implied in yours and others question, - besides I like playing with a model plane. (I allow myself this small amusement, though I think, most of the results of this flights are  foreseeable.)                                                                       

                                                                                       

                                                                                                           
                                          Regards

                                          DaveL


                                          On Jul 27, 2013, at 5:26 PM, Gabor Dobos <dobosg001@...> wrote:

                                          On 2013-07-15 05:49, David Lang wrote:
                                          The question remains whether the process of un-tethered dynamic soaring is an energy-robust cycle, when constrained to an "average no net altitude or positional drift". My guess is, that  until a time domain simulation (or, say, an early-on piloted example) of this process is demonstrated such that said demonstration reflects the deleterious disturbing effects on trajectory of the actual on-board energy harvesting device, this scheme is highly conjectural. Lest I be accused of singling out this scheme for criticism, the same can be said of many of the schemes being bandied about on this forum. However, this scheme does set the flag to raise the question "once the tether is abandoned, then what besides wind gradient and gravity serves to effectively hold this flying device into the "teeth of wind"?

                                          DaveL


                                          DaveL,
                                          You ought to discusss with JoeF, since his opinion is at the other extreme by saying that all my ideas have been  well known almost since the beginning of time... -:) Excuse me, but I don't know what to think upon reading your comment above. To tell the truth, I do not think that you don't know the answers.  Are  your questions  perhaps jokes just to test me?  If so, I mustn't even believe what you're asking... -:)

                                          The idea isn't conjectural. It is based on facts and technical evidence e.g.:

                                          • piloted example:

                                          "The demonstrator’s rotors are driven by advanced electric motors powered by rechargeable batteries
                                          The demonstrator’s rotors when on the ground can be tilted forward and the aircraft pointed into wind to allow the rotors to windmill and recharge the aircraft’s electrical storage device."
                                          See more::
                                           http://www.agustawestland.com/news/agustawestland-unveils-project-zero-tilt-rotor-technology-demonstrator    
                                          There are a lot of findings with motorgliders. The " disturbing effects "of the prop.  entail nothing unusual. These can be calculated, see JoeF's  comments about RATs
                                          • what holds this flying device into the "teeth of wind"?                                                                                                         
                                          Apart from wind gradient and gravity, the inertial mass

                                          • energy-robust cycle
                                          Of course, simulations are seeking a borderline case, to show the best or worse case. But in a practical case the practical question is not that,  The question is whether the device is capable of withstanding the huge energy density of the Jet.  We have to worry about whether we get back the glider as a glider or a dump of  debris   and not of that energy-neutral trajectory.    

                                          <gifiagac.png>

                                          Wing-test of a model-glider


                                          Gabor



                                      • Gabor Dobos
                                        ... Yes. Prof. Roberts early device was an autogiro. Liifting the device to the desired height occurred by driving the windmills with a motor-generator,
                                        Message 20 of 25 , Aug 4, 2013
                                          On 2013-07-28 22:34, Bob Stuart wrote:

                                          has anyone ever heard about an electric aircraft or helicopter being powered through a tether?


                                          Yes. Prof. Roberts early device was an autogiro. Liifting the device to the desired height occurred by driving the windmills with a motor-generator, powered from the ground through a tether.
                                          SkyWIndPower applies the same system even today: http://www.skywindpower.com


                                          On 2013-07-28 22:34, Bob Stuart wrote:
                                           

                                          I think we have to allow a downwind sweep to give these much chance at all.  The Albatross is a champion of dynamic soaring, and it follows the annual winds, at home anywhere, but at a fixed location on land only yearly.  


                                          I note that Paul MacCready was a champion soaring pilot, but when his company set out to build a station-keeping aircraft as a robotic tall antenna, they went with solar.

                                          While we are here, has anyone ever heard about an electric aircraft or helicopter being powered through a tether?  I'd be inclined to try high frequency AC through a single conductor, with a capacitor on board.  Combined with kiting, it might make a good way to keep an antenna up, at least.  With all that hardware in the air anyway, it could be a fly-gen with a ground battery bank, able to sustain itself in remote locations.  

                                          Bob Stuart

                                          On 28-Jul-13, at 1:58 PM, David Lang wrote:

                                          JoeF,


                                          Your conjectures entail a lot of "what if's" regarding global wind state, plentiful energy-reception stations, etc.

                                          What I am getting at is much simpler and (I think) to the point regarding tetherless glider energy harvesting in general. Suppose you took a boundary-soaring seagull, which has the ability to demonstrate the maintenance of "average position" by using wind gradient……now, add a little drogue-chute to its tail……how might it fair under the influence of that additional drag….could it muster enough additional energy harvest from the wind gradient to still maintain average position?

                                          My intuitive assessment of tetherless (ie. non-externally-equilibrated wind force) energy harvesting envisions that reverse-effective forces (ie. d'Alambert forces) are all you have
                                           at your disposal to "stand your ground against the wind" (ie. in order to force relative wind to persist at useful levels.....try harvesting energy in a uniform 200 kt jet stream with this scheme…..all you end up doing is being swept across the countryside),  equilibrating d'Alembert forces cannot exceed the product of your mass and acceleration; This is as opposed to other schemes that have an external "grip" on something, said external grip being: a "tether" (for most AWE schemes),   "keel/hull-drag" (for sailboats), "tires contacting ground-friction" (for a propeller driven vehicle that can move into the teeth of the wind", etc.

                                          If we intend to be serious purveyors of AWE, we must believably quantify the amount of energy we imply that we can harvest.

                                          DaveL



                                          On Jul 28, 2013, at 12:09 PM, Joe Faust <joefaust333@...> wrote:

                                          Re:   On Sun, Jul 28, 2013 at 10:48 AM, David Lang <SeattleDL@...> wrote:
                                          some of which
                                          1. is used by the process itself to maintain an average position in space (ie. so as not to progressively loose altitude, or be swept down-stream like a boat in a river), 


                                          No-tether-to-ground: Allow downwind sweep case
                                            This note does not handle all the good points presented for discussion, but I address momentarily only an alternative scenario that has been mentioned in forum at some point.   This note regards a free-flying AWES that is allowed to drift regularly downwind and not try to stay positioned for any specific fixed ground station.  For example, let a RAT-embedded dynamically-soaring sailplane enter the edges of a jet stream to harvest energy in the gradients; but let the sailplane travel regularly eastward  in the general direction of the jet stream of the example.  Have earth-surround ground receivers continually available; that is, soon another ground station receiver will be available for dumping harvested energy products.   Do not expend aloft energy to stay over, say, Kansas, but allow the AWES to have a ground trace around the world again and again.    This scenario would then not expend energy "to maintain" any average position in space as regards the being swept down stream.  However, there would still be the expenditure of some energy for maintaining altitude of the craft.     This scenario might be termed: Allow downwind sweep case.  




                                        • Gabor Dobos
                                          Gentlemen, it is time to respond to your posts below. Take a look please at the following two links: This is the proof of concept of my energy harvesting
                                          Message 21 of 25 , Jan 5, 2014
                                            Gentlemen,

                                            it is time to respond to your posts below. Take a look please at the following two links:
                                            This is the proof of concept of my energy harvesting gliders ("IFO") that you wanted to see.

                                            "Re-GENERATION SYSTEM:
                                            Our electric re-gen systems provides battery charging during non-powered flight/gliding. This system can also be used with our folding prop to force the motor to stop so the prop can fold. "
                                            http://www.electraflyer.com/price_list.php

                                            The following link contains a photo of the aircraft:
                                            http://www.planeandpilotmag.com/pilot-talk/more-pilot-talk/light-sport-chronicles-profiles-in-vision-randall-fishman.html

                                            I have received some further details from the company about the solution and how it functions. It can be integrated into our preliminary plan, though of course a further development is needed.
                                            There is nothing unforeseeable. As I told before

                                            The larger part of the whole system can be developed and constructed this way, using "off-the-shelf" components. Other parts of the system need further research work.


                                            DaveS, yes, dreams are dreams. But don't forget: toda la vida es sueno, and I dare to dream great, though sometimes it is un frenesi, sometimes una illusion, sometimes una ficción. But now (and for some time now) it is the reality.

                                            Doug, just one question: are you serious? I am.

                                            Gabor

                                            -----------------------------------------------------------------------

                                            PS.: Your cited posts:

                                            On 2013-06-16 20:54, dave santos wrote:
                                            Why no small cheap proof-of-concept flying model? This is both the earliest validation of tetherless AWE, and the critical-path to scaling up
                                            "...toda la vida es sueño, y los sueños, sueños son..."


                                            On 2013-08-23 17:18, Doug wrote:
                                            If you are serious, get a radio controlled glider and use batteries. Forget the liquified air for now. .... See if your basic concept is even viable before ruining your otherwise interesting idea with a second questionable concept.
                                            I actually like your idea with the gliders in-and-out of the jet stream. I'd love to see it work! I ask the pertinent questions not to say "no", but to say "yes". The "yes" part means "Let's hear some more details indicating that we should take this to the next step."
                                            I say we stick to the topic and solve the challenge!

                                            On 2013-09-04 17:44, dougselsam@... wrote:
                                            Anyway,if anyone is serious about wanting to get economic AWE systems up and running I am open to collaboration.
                                            :)
                                            Doug S,

                                          • dougselsam
                                            Hi Gabor: One thing almost every new idea in wind energy has in common is being possible in the sense that a proof of concept is not really in question.
                                            Message 22 of 25 , Jan 6, 2014
                                              Hi Gabor:
                                              One thing almost every "new idea" in wind energy has in common is being "possible" in the sense that a "proof of concept" is not really in question.
                                              Good to know, you at least respect the laws of physics.  That is a start.

                                              You're basically re-stating that your idea "does not violate the laws of physics".  For every economically-efficient way of harnessing power, there are perhaps a million non-economical ways to harness SOME power, but by spending far more money than that power is worth.

                                              Virtually ALL the bad ideas use the laws pf physics to make power.  Look at the tilting disc that pushes and  pulls on pistons.  It clearly does not violate any laws of physics, just that it costs more and produces far less power than a propeller.  It's not worth building, no matter how many "geniuses" re-invent it.

                                              Anyway, I will wait with bated breath (whatever that is) to hear of the economic success of your system.  Hey, you never know!  Good luck!
                                              :)
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