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RE: [AirborneWindEnergy] Drag

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  • Darin Selby
    Check out the Whalepower design that marine scientist Frank Fish has come up with. It improves the efficiency blade rotors and plane wings lift by 20% The
    Message 1 of 27 , Oct 21, 2009
      Check out the Whalepower design that marine scientist Frank Fish has come up with.  It improves the efficiency blade rotors and plane wings lift by 20%  The leading edge of the pectoral fin of the Humpback whale was modeled, and disovered that by combing the airflow going over the wing surface has very beneficial results.  One is releasing drag, and the other is the quieting of the spinning rotor blade:
       http://rexresearch.com/whalewing/whalewing.htm


      To: AirborneWindEnergy@yahoogroups.com
      From: christopher.m.carlin@...
      Date: Tue, 20 Oct 2009 21:17:51 +0100
      Subject: Re: [AirborneWindEnergy] Drag

       
      Drag doesn't help performance but it can help stability. Certainly there is a trade between trim drag and stability in airplanes. I would expect it to apply to kites also.

      Regards,

      Chris
      On Oct 19, 2009, at 7:04 PM, Dan Fink wrote:

      Hmmm. How can increasing drag possibly help the cP of a wind turbine? I 
      just don't see it.

      "Lift" does not always have anything to do with any sort of airfoil or 
      Bernoulli "sucking" effect on a wind turbine rotor. "Lift" is 
      experienced by any object in the wind where the orientation of the 
      object allows the air flow to make it move; the more efficiently the 
      better. Add some Bernoulli and you increase your effect.

      It seems all my math does not apply here on this list.... why is that?

      DAN

      Joe Faust wrote:
      > 
      > 
      > Drag plays many positive advantageous roles in AWECS.
      > 
      > This thread is suggested as one place to bring forward the where, when, 
      > and how drag may play to effectively have AWECS be all it might be.
      > 
      > What have we .... about drag?





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    • Bob Stuart
      Bear in mind that these are essentially anti-stall devices. They let us operate with less wind, but there is not much energy to extract at such speeds.
      Message 2 of 27 , Oct 21, 2009
        Bear in mind that these are essentially anti-stall devices.  They let us operate with less wind, but there is not much energy to extract at such speeds.  Meanwhile, there could be an increase in drag, if only because of the difficulty of construction, at the most productive wind speeds.  

        Re: Drag - the parasitic drag of lines normal to the wind can be halved by adding a simple, semi-rigid vane to the trailing edge.  Much greater reductions are probably possible with shaped fairings or molded, unidirectional lines.
        We might put a bug in the ear of the sailboat racers to prod development.

        Bob Stuart




        On 21-Oct-09, at 11:18 AM, Darin Selby wrote:

         

        Check out the Whalepower design that marine scientist Frank Fish has come up with.  It improves the efficiency blade rotors and plane wings lift by 20%  The leading edge of the pectoral fin of the Humpback whale was modeled, and disovered that by combing the airflow going over the wing surface has very beneficial results.  One is releasing drag, and the other is the quieting of the spinning rotor blade:

         http://rexresearch. com/whalewing/ whalewing. htm


        To: AirborneWindEnergy@ yahoogroups. com
        From: christopher. m.carlin@ btinternet. com
        Date: Tue, 20 Oct 2009 21:17:51 +0100
        Subject: Re: [AirborneWindEnergy ] Drag

         
        Drag doesn't help performance but it can help stability. Certainly there is a trade between trim drag and stability in airplanes. I would expect it to apply to kites also.

        Regards,

        Chris
        On Oct 19, 2009, at 7:04 PM, Dan Fink wrote:

        Hmmm. How can increasing drag possibly help the cP of a wind turbine? I 
        just don't see it.

        "Lift" does not alw


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      • Bob Stuart
        Re-posted to include news about bumpy, whale-inspired leading edges, truncated mysteriously: Bear in mind that these are essentially anti-stall devices. They
        Message 3 of 27 , Oct 21, 2009
          Re-posted to include news about bumpy, whale-inspired leading edges,
          truncated mysteriously:

          Bear in mind that these are essentially anti-stall devices. They let
          us operate with less wind, but there is not much energy to extract at
          such speeds. Meanwhile, there could be an increase in drag, if only
          because of the difficulty of construction, at the most productive
          wind speeds.


          Re: Drag - the parasitic drag of lines normal to the wind can be
          halved by adding a simple, semi-rigid vane to the trailing edge.
          Much greater reductions are probably possible with shaped fairings or
          molded, unidirectional lines.

          Bob Stuart

          On 21-Oct-09, at 11:18 AM, Darin Selby wrote:
          > Check out the Whalepower design that marine scientist Frank Fish
          > has come up with. It improves the efficiency blade rotors and
          > plane wings lift by 20% The leading edge of the pectoral fin of
          > the Humpback whale was modeled, and disovered that by combing the
          > airflow going over the wing surface has very beneficial results.
          > One is releasing drag, and the other is the quieting of the
          > spinning rotor blade:
          >
          > http://rexresearch.com/whalewing/whalewing.htm
        • Bob Stuart
          Thinking over alternatives to leading-edge bumps as a way to take advantage of lower winds, I wonder if anyone plans to adjust the size or number of the kites
          Message 4 of 27 , Oct 21, 2009
            Thinking over alternatives to leading-edge bumps as a way to take advantage of lower winds, I wonder if anyone plans to adjust the size or number of the kites they loft, according to conditions?  With 3 sets of sails, the same generator and lines could be run much closer to capacity most of the time.  How about kites that change shape or size, as necessary?  Presumably, a roller-furler could be fitted to a flexi-foil.  Or is spilling wind close enough to optimum?

            Bob Stuart

          • christopher carlin
            Spilling wind - french reefing to a sailor - generally is hard on structure. It usually results in luffing and unsteady loads. Variable geometry - flaps
            Message 5 of 27 , Oct 21, 2009
              Spilling wind - french reefing to a sailor - generally is hard on structure. It usually results in luffing and unsteady loads. Variable geometry - flaps spoilers or furling works well in airplanes. Basically a weight trade. Is the extra weight aloft worth the benefits?

              Chris
              On Oct 21, 2009, at 7:49 PM, Bob Stuart wrote:

              Thinking over alternatives to leading-edge bumps as a way to take advantage of lower winds, I wonder if anyone plans to adjust the size or number of the kites they loft, according to conditions?  With 3 sets of sails, the same generator and lines could be run much closer to capacity most of the time.  How about kites that change shape or size, as necessary?  Presumably, a roller-furler could be fitted to a flexi-foil.  Or is spilling wind close enough to optimum?


              Bob Stuart



            • Darin Selby
              Is this the most efficient design for a lifter kite to use for this purpose? http://kap-man.de/e-manlifter.htm To: AirborneWindEnergy@yahoogroups.com From:
              Message 6 of 27 , Oct 21, 2009
                Is this the most efficient design for a lifter kite to use for this purpose?  http://kap-man.de/e-manlifter.htm


                To: AirborneWindEnergy@yahoogroups.com
                From: christopher.m.carlin@...
                Date: Wed, 21 Oct 2009 20:14:49 +0100
                Subject: Re: [AirborneWindEnergy] Variability

                 
                Spilling wind - french reefing to a sailor - generally is hard on structure. It usually results in luffing and unsteady loads. Variable geometry - flaps spoilers or furling works well in airplanes. Basically a weight trade. Is the extra weight aloft worth the benefits?

                Chris
                On Oct 21, 2009, at 7:49 PM, Bob Stuart wrote:

                Thinking over alternatives to leading-edge bumps as a way to take advantage of lower winds, I wonder if anyone plans to adjust the size or number of the kites they loft, according to conditions?  With 3 sets of sails, the same generator and lines could be run much closer to capacity most of the time.  How about kites that change shape or size, as necessary?  Presumably, a roller-furler could be fitted to a flexi-foil.  Or is spilling wind close enough to optimum?


                Bob Stuart






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              • brooksdesign
                Many years ago in my Hang Gliding days, someone was producing a fairing coating for the cables that did just that. I don t recall the name, place or date of
                Message 7 of 27 , Oct 21, 2009
                  Many years ago in my Hang Gliding days, someone was producing a fairing coating for the cables that did just that. I don't recall the name, place or date of such product or how it played out but something to look into.
                  -brooks


                  -----Original Message-----
                  From: Bob Stuart
                  Sent: Oct 21, 2009 1:16 PM
                  To: AirborneWindEnergy@yahoogroups.com
                  Subject: Re: [AirborneWindEnergy] Turbulence - was Drag

                   

                  Bear in mind that these are essentially anti-stall devices.  They let us operate with less wind, but there is not much energy to extract at such speeds.  Meanwhile, there could be an increase in drag, if only because of the difficulty of construction, at the most productive wind speeds.  


                  Re: Drag - the parasitic drag of lines normal to the wind can be halved by adding a simple, semi-rigid vane to the trailing edge.  Much greater reductions are probably possible with shaped fairings or molded, unidirectional lines.
                  We might put a bug in the ear of the sailboat racers to prod development.

                  Bob Stuart




                  On 21-Oct-09, at 11:18 AM, Darin Selby wrote:

                   

                  Check out the Whalepower design that marine scientist Frank Fish has come up with.  It improves the efficiency blade rotors and plane wings lift by 20%  The leading edge of the pectoral fin of the Humpback whale was modeled, and disovered that by combing the airflow going over the wing surface has very beneficial results.  One is releasing drag, and the other is the quieting of the spinning rotor blade:

                   http://rexresearch. com/whalewing/ whalewing. htm


                  To: AirborneWindEnergy@ yahoogroups. com
                  From: christopher. m.carlin@ btinternet. com
                  Date: Tue, 20 Oct 2009 21:17:51 +0100
                  Subject: Re: [AirborneWindEnergy ] Drag

                   
                  Drag doesn't help performance but it can help stability. Certainly there is a trade between trim drag and stability in airplanes. I would expect it to apply to kites also.

                  Regards,

                  Chris
                  On Oct 19, 2009, at 7:04 PM, Dan Fink wrote:

                  Hmmm. How can increasing drag possibly help the cP of a wind turbine? I 
                  just don't see it.

                  "Lift" does not alw


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                • Dave Culp
                  French reefing to an *English* sailor. No doubt English reefing or similar to the French. :-) Often called scandalizing the sail in America which
                  Message 8 of 27 , Oct 21, 2009
                    "French reefing" to an *English* sailor. No doubt "English reefing" or
                    similar to the French. :-) Often called "scandalizing" the sail in
                    America which somehow carries the same "naughty" or "foolish" theme as
                    the "french/english" thing. I'm referring, of course, to the various
                    "french letter"/"english letter"; "french disease"/"english disease"
                    etc, etc--which have gone on for centuries between the two cultures.

                    Funny stuff.

                    Dave

                    On Wed, Oct 21, 2009 at 12:14 PM, christopher carlin
                    <christopher.m.carlin@...> wrote:
                    >
                    >
                    >
                    > Spilling wind - french reefing to a sailor - generally is hard on structure. It usually results in luffing and unsteady loads. Variable geometry - flaps spoilers or furling works well in airplanes. Basically a weight trade. Is the extra weight aloft worth the benefits?
                    >
                    > Chris
                  • dave santos
                    Bob,   You are right to suppose a quiver of kites maximizes AWE capacity. There is no one-kite-does-it-all, but many are going that route. Varying the size
                    Message 9 of 27 , Oct 21, 2009
                      Bob,
                       
                      You are right to suppose a "quiver" of kites maximizes AWE capacity. There is no one-kite-does-it-all, but many are going that route. Varying the size & number of kites is quite useful to adapt to load, location, season, & daily conditions. Stored quiver stops the wear clock, its flight hours that count.
                       
                      Existing highly variable wings are too heavy for current kite applications, but similar wings will someday rule the jet streams. Passive variability helps, like elastic TE bridle lines, or membrane decambering when a LE spar bends, like a mainsail mast does in a blow.
                       
                      The varidrogue approach to variability offers a huge drag range, close to 100/1, Common depowerable kites have a variability during sweep around 5/1. Varying sweep from parked high to sweeping wide depowered is around 10/1. These guesstimates come from deep self-hypnosis sessions, then i have to mop up all the drool,
                       
                      daveS
                       
                      PS How come the English & French always get the credit? They should call it Mexican Reefing ;^)
                       
                       

                      --- On Wed, 10/21/09, Bob Stuart <bobstuart@...> wrote:

                      From: Bob Stuart <bobstuart@...>
                      Subject: Re: [AirborneWindEnergy] Variability
                      To: AirborneWindEnergy@yahoogroups.com
                      Date: Wednesday, October 21, 2009, 1:49 PM

                       
                      Thinking over alternatives to leading-edge bumps as a way to take advantage of lower winds, I wonder if anyone plans to adjust the size or number of the kites they loft, according to conditions?  With 3 sets of sails, the same generator and lines could be run much closer to capacity most of the time.  How about kites that change shape or size, as necessary?  Presumably, a roller-furler could be fitted to a flexi-foil.  Or is spilling wind close enough to optimum?

                      Bob Stuart


                    • Darin Selby
                      How about this concept of a kytoon, where the wind makes the tail flap to create electricity that is sent down a dual-conductive tether!
                      Message 10 of 27 , Oct 21, 2009
                        How about this concept of a kytoon, where the wind makes the tail flap to create electricity that is sent down a dual-conductive tether!

                        http://www.youtube.com/watch?v=pGPRceDDitQ&feature=fvsr

                        To: AirborneWindEnergy@yahoogroups.com
                        From: dave@...
                        Date: Wed, 21 Oct 2009 14:25:26 -0700
                        Subject: Re: [AirborneWindEnergy] Variability

                         
                        "French reefing" to an *English* sailor. No doubt "English reefing" or
                        similar to the French. :-) Often called "scandalizing" the sail in
                        America which somehow carries the same "naughty" or "foolish" theme as
                        the "french/english" thing. I'm referring, of course, to the various
                        "french letter"/"english letter"; "french disease"/"english disease"
                        etc, etc--which have gone on for centuries between the two cultures.

                        Funny stuff.

                        Dave

                        On Wed, Oct 21, 2009 at 12:14 PM, christopher carlin
                        <christopher. m.carlin@ btinternet. com> wrote:
                        >
                        >
                        >
                        > Spilling wind - french reefing to a sailor - generally is hard on structure. It usually results in luffing and unsteady loads. Variable geometry - flaps spoilers or furling works well in airplanes. Basically a weight trade. Is the extra weight aloft worth the benefits?
                        >
                        > Chris



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                      • Dave Culp
                        They do my friend, they do. There s also the Mexican takedown, where the sails are dropped in the water, then run over... There s also the Samuri takedown (Cut
                        Message 11 of 27 , Oct 21, 2009
                          They do my friend, they do. There's also the Mexican takedown, where
                          the sails are dropped in the water, then run over... There's also the
                          Samuri takedown (Cut the rope. Really!)

                          But the French/English thing seems to dominate on the European side of
                          the pond. They've been playing this game longer than we have, you see.
                          ;-)

                          Dave

                          On Wed, Oct 21, 2009 at 3:22 PM, dave santos <santos137@...> wrote:

                          >
                          > PS How come the English & French always get the credit? They should call it Mexican Reefing ;^)
                        • Dean
                          Hi Darin and Group, Love it, the shape of things to come. Dan l
                          Message 12 of 27 , Oct 22, 2009
                            Hi Darin and Group,

                            Love it, the shape of things to come.

                            Dan'l

                            --- In AirborneWindEnergy@yahoogroups.com, Darin Selby <darin_selby@...> wrote:
                            >
                            >
                            > How about this concept of a kytoon, where the wind makes the tail flap to create electricity that is sent down a dual-conductive tether!
                            > http://www.youtube.com/watch?v=pGPRceDDitQ&feature=fvsr
                            > To: AirborneWindEnergy@yahoogroups.com
                            > From: dave@...
                            > Date: Wed, 21 Oct 2009 14:25:26 -0700
                            > Subject: Re: [AirborneWindEnergy] Variability
                            >
                            >
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                            >
                            >
                            > "French reefing" to an *English* sailor. No doubt "English reefing" or
                            >
                            > similar to the French. :-) Often called "scandalizing" the sail in
                            >
                            > America which somehow carries the same "naughty" or "foolish" theme as
                            >
                            > the "french/english" thing. I'm referring, of course, to the various
                            >
                            > "french letter"/"english letter"; "french disease"/"english disease"
                            >
                            > etc, etc--which have gone on for centuries between the two cultures.
                            >
                            >
                            >
                            > Funny stuff.
                            >
                            >
                            >
                            > Dave
                            >
                            >
                            >
                            > On Wed, Oct 21, 2009 at 12:14 PM, christopher carlin
                            >
                            > <christopher.m.carlin@...> wrote:
                            >
                            > >
                            >
                            > >
                            >
                            > >
                            >
                            > > Spilling wind - french reefing to a sailor - generally is hard on structure. It usually results in luffing and unsteady loads. Variable geometry - flaps spoilers or furling works well in airplanes. Basically a weight trade. Is the extra weight aloft worth the benefits?
                            >
                            > >
                            >
                            > > Chris
                            >
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                            > _________________________________________________________________
                            > Hotmail: Trusted email with Microsoft's powerful SPAM protection.
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                          • dave santos
                            Funny this topic came up, Brook s & i actually pioneered this genre with the legendary Austin Robot Group starting in the late eighties & made many fish-like
                            Message 13 of 27 , Oct 22, 2009
                              Funny this topic came up, Brook's & i actually pioneered this genre with the legendary Austin Robot Group starting in the late eighties & made many fish-like micro-LTAs. The incredible weight discipline required for micro-LTA nicely preadapts us for good AWE.
                               
                              I did not find a link to one of many fish-tail variants, but this flapping-wing/running-leg model gives an idea of the work, still hardly surpassed after almost 20 years. Maybe Brooks has more links or can port some legacy video. Sadly, we learned helium is a very marginal basis for aviation.
                               
                              www.robotgroup.org/history/ projects/ roboblimp.html
                               

                              --- On Thu, 10/22/09, Dean <spiralairfoil@...> wrote:

                              From: Dean <spiralairfoil@...>
                              Subject: [AirborneWindEnergy] Re: fish blimp
                              To: AirborneWindEnergy@yahoogroups.com
                              Date: Thursday, October 22, 2009, 7:06 AM

                               
                              Hi Darin and Group,

                              Love it, the shape of things to come.

                              Dan'l

                              --- In AirborneWindEnergy@ yahoogroups. com, Darin Selby <darin_selby@ ...> wrote:
                              >
                              >
                              > How about this concept of a kytoon, where the wind makes the tail flap to create electricity that is sent down a dual-conductive tether!
                              > http://www.youtube. com/watch? v=pGPRceDDitQ& feature=fvsr
                              > To: AirborneWindEnergy@ yahoogroups. com
                              > From: dave@...
                              > Date: Wed, 21 Oct 2009 14:25:26 -0700
                              > Subject: Re: [AirborneWindEnergy ] Variability
                              >
                              >
                              >
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                              >
                              >
                              >
                              >
                              > "French reefing" to an *English* sailor. No doubt "English reefing" or
                              >
                              > similar to the French. :-) Often called "scandalizing" the sail in
                              >
                              > America which somehow carries the same "naughty" or "foolish" theme as
                              >
                              > the "french/english" thing. I'm referring, of course, to the various
                              >
                              > "french letter"/"english letter"; "french disease"/"english disease"
                              >
                              > etc, etc--which have gone on for centuries between the two cultures.
                              >
                              >
                              >
                              > Funny stuff.
                              >
                              >
                              >
                              > Dave
                              >
                              >
                              >
                              > On Wed, Oct 21, 2009 at 12:14 PM, christopher carlin
                              >
                              > <christopher. m.carlin@ ...> wrote:
                              >
                              > >
                              >
                              > >
                              >
                              > >
                              >
                              > > Spilling wind - french reefing to a sailor - generally is hard on structure. It usually results in luffing and unsteady loads. Variable geometry - flaps spoilers or furling works well in airplanes. Basically a weight trade. Is the extra weight aloft worth the benefits?
                              >
                              > >
                              >
                              > > Chris
                              >
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                              > ____________ _________ _________ _________ _________ _________ _
                              > Hotmail: Trusted email with Microsoft's powerful SPAM protection.
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                            • Joe Faust
                              This post is from Doug Selsam for the group for this thread sent through moderator: =================================================== fromdougselsam
                              Message 14 of 27 , Oct 22, 2009

                                This post is from Doug Selsam for the group for this thread sent through moderator:

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

                                fromdougselsam <doug@...>
                                toAirborneWindEnergy-owner@yahoogroups.com

                                dateThu, Oct 22, 2009 at 1:22 PM
                                subjectRe: Whalepower (Whalebumps)
                                mailed-byreturns.groups.yahoo.com
                                signed-byyahoogroups.com

                                Glad to know my dripping paint has a purpose. ;)  So the drips have a name - whale bumps - who knew?  Maybe we should run some tests, with the bumps and without, and verify that 20% number.
                                Beware of press releases substituting for real research.  This idea has been around for awhile now and I haven't seen any results except for a lot of press, but no examples of any turbine talking advantage of whale bumps.

                                You hear stuff like this all the time.  I'd say concentrate on getting something working at all, then improve on 1000 years of airfoil fine-tuning later.  Turbulators have been around in aviation for many years, and have the same effect.  If there were any true advantage to whale bumps, would they be "stick-on bumps" applied over a unidirectional fiber skin?  Or would we expect to waver our otherwise straight unidirectional roving layup?  Oh forget it I have probably lost most of the audience by now.

                                Anyway let me just say that there is room for endless speculation in this field that combines 3 invisible forces: wind, magnetism, and electricity.  There are lots of people on these lists who live in their mom's basement and have all day to discuss a press release as though it were a fact etc.  Let me just say that you have to have your feet on the ground before you will ever make any progress in this field of flying wind turbines, or any kind of wind turbine, or really any machine period.

                                Much of what we read on these lists is as though we were talking about internal combustion engines and someone says they want to introduce a lot more fuel without more air to go with it.  That is like saying you want to increase the solidity of a rotor by adding more blades, or a continuous blade.  The more blades you add to the circle, the more you bog the machine down.  By that time, you are running the engine with the choke on all the time, and you have a drag machine.  People get tired of having the choke on and want to hit the power band, so they get rid of 96% of their structure and find, lo and behold, less blade = more power.  Fly blade, fly!  Then there are the whale bumps.  Here's a limerick:

                                "A girl was quite down in the dumps
                                from having developed whale bumps
                                The chafing of her thighs
                                was a sight for sore eyes
                                Especially when walking with pumps"

                                :)
                                Doug Selsam
                                P.S. Press Release: Intergalactic SuperPhD ultra-scientist Frank Whale has developed Fish Bumps for blades!  No self-respecting fish in his right mind would be caught dead without fish bumps.  So get witgh what is hip, and learn a lesson from your ancient ancestors: Fishpower.  Seeking investors.  80% extra power is "projected"  - Google? ;)

                              • Benhaiem
                                Hi Peters and the group, Crosswind accelerations are not a problem and cannot be avoid when a high part of the fly window is used.The cyclic hydraulic storing
                                Message 15 of 27 , Oct 23, 2009

                                  Hi Peters and the group,

                                  Crosswind accelerations are not a problem and cannot be avoid when a high part of the fly window is used.The cyclic hydraulic storing smooths the production before entering to generators.

                                  Half-turn must be quick and with a low radius:so the driving device must be near or on the kite.When I try crosswind trajectories (with 2 or 4 lines 4 m² or 9 m² kites,ratio LD = 4 or less),there are no problem during trajectory.With high ratio LD (8 to 12 and more if possible),the speed is higher,and so the kinetic energy of the kite:so high speed can be an element for trajectory kite stabilisation.

                                  OrthoKiteBunch with only one kite is OrthoKite,with orthogonal transmission between lines and double lever in alternance.So first trials will determine gains of useful tangential strengths.

                                  Pierre Benhaïem

                                  OrthoKiteBunch 

                                   

                                   

                                   

                                • Benhaiem
                                  (for my precedent message reading Peter (not s). Experience of drag with solar balloon jumping After
                                  Message 16 of 27 , Oct 23, 2009

                                    (for my precedent message  reading Peter (not s).

                                    Experience of drag with solar balloon jumping 

                                    After jump the 200 N lift balloon and me go down,then the balloon goes on (inversing kinetic energy):I must pull the balloon for 1/5 of descent;the difference is balloon drag.Such a balloon as AWE would have a valve to the top for cyclic descent.A 400 m3 balloon produces 1800 J/10 seconds.Little power for little cost (10 kg of HDPE).

                                    Pierre Benhaïem

                                    OrthoKiteBunch  

                                  • Darin Selby
                                    If this design is for an incredible art exhibit, it is really cool. Though, if you are wanting to make a practical electricity-making device, it is way too
                                    Message 17 of 27 , Oct 23, 2009
                                      If this design is for an incredible art exhibit, it is really cool.  Though, if you are wanting to make a practical electricity-making device, it is way too elaborate.


                                      To: AirborneWindEnergy@yahoogroups.com
                                      From: pierre.benhaiem@...
                                      Date: Fri, 23 Oct 2009 16:52:13 +0000
                                      Subject: [AirborneWindEnergy] Drag

                                       

                                      Hi Peters and the group,
                                      Crosswind accelerations are not a problem and cannot be avoid when a high part of the fly window is used.The cyclic hydraulic storing smooths the production before entering to generators.
                                      Half-turn must be quick and with a low radius:so the driving device must be near or on the kite.When I try crosswind trajectories (with 2 or 4 lines 4 m² or 9 m² kites,ratio LD = 4 or less),there are no problem during trajectory.With high ratio LD (8 to 12 and more if possible),the speed is higher,and so the kinetic energy of the kite:so high speed can be an element for trajectory kite stabilisation.
                                      OrthoKiteBunch with only one kite is OrthoKite,with orthogonal transmission between lines and double lever in alternance.So first trials will determine gains of useful tangential strengths.
                                      Pierre Benhaïem
                                      OrthoKiteBunch 
                                       
                                       
                                       



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