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Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)

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  • dave santos
    This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software toolbox was still only partly
    Message 1 of 8 , Oct 27, 2013
      This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software "toolbox" was still only partly developed. The dynamic force vectors are nicely animated. Concurrent wind-tunnel testing with staked-out wings also necessarily omitted tethers. Open-source AWE was able to see in this work a wonderful unintended result, the first numeric simulation and scale windtunnel testing of a mega-arch kite fixed crosswind, clearly displaying empirically well-known but unformalized kite dynamics (phugoid and dutch-roll mixed-modes). 

      A kPower working conjecture is these dynamics can work at the kilometer gigawatt unit-scale to pump groundgens by passive oscillations. The scaled-up arch kites proposed would be of megascale rope load-path and membrane kixel construction. Operational, physical, and design similarity cases include mega-scale trawl-nets and sports-field-tarp handling. A 300m2 flight demonstrator (Mothra1, 2012) met every design expectation and far larger kites are in planning. Critique and suggestions invited.
       
      A link as requested by MikeB and PierreB (sorry for the delay)-

    • Pierre BENHAIEM
      Thank you DaveS, Swept area is only the projection (low value since the kite flies with low incidence at the top) of arch on a perpendicular plan face to
      Message 2 of 8 , Oct 27, 2013

        Thank you DaveS,

         

        Swept area is only the projection (low value since the kite flies with low incidence at the top) of arch on a perpendicular plan face to wind,comprising the (low) amplitude of oscillations.So an arch of 1 km/0.2 km (200,000 m²) will have a swept area around 100,000 m²,probably far less.Oscillations can be divided in a power phase downwind,and a recovering phase (the same for yoyo) here due to the elasticity of material.In an old post DaveL indicates a value of roughly 15% of the whole or on Betz'limit (I dont remember) for drag power.The recovering phase "eats" some energy and half of time.So 6% could be an optimist value.With wind speed = 10 m/s,the power is something like 6 MW. Adding replacement of blue tarp each 6 months (by being very optimist). Price of blue tarp 1$/m².For 20 years the expense of blue tarp is 8,000,000 $, far more than blades for a 6 MW conventional wind turbine.Adding orientation face to the winds (not possible for an arch with two anchors), maintenance (which working for replacement of blue tarp), management,etc.

        PierreB

        > Message du 27/10/13 19:03
        > De : "dave santos"
        > A : "AWE"
        > Copie à : "Roland Schmehl" , "jeroenbreukels@..."
        > Objet : [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
        >
        >  

        >

        This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software "toolbox" was still only partly developed. The dynamic force vectors are nicely animated. Concurrent wind-tunnel testing with staked-out wings also necessarily omitted tethers. Open-source AWE was able to see in this work a wonderful unintended result, the first numeric simulation and scale windtunnel testing of a mega-arch kite fixed crosswind, clearly displaying empirically well-known but unformalized kite dynamics (phugoid and dutch-roll mixed-modes). 

        >
        A kPower working conjecture is these dynamics can work at the kilometer gigawatt unit-scale to pump groundgens by passive oscillations. The scaled-up arch kites proposed would be of megascale rope load-path and membrane kixel construction. Operational, physical, and design similarity cases include mega-scale trawl-nets and sports-field-tarp handling. A 300m2 flight demonstrator (Mothra1, 2012) met every design expectation and far larger kites are in planning. Critique and suggestions invited.
         
         
         
        A link as requested by MikeB and PierreB (sorry for the delay)-
        >
        >
      • Pierre BENHAIEM
        A part of the arch can work crosswind ,but not at high speed,due to the own limits of the arch.So the power could be more,perhaps 10 MW.But this value is yet
        Message 3 of 8 , Oct 27, 2013

          A part of the arch can work "crosswind",but not at high speed,due to the own limits of the arch.So the power could be more,perhaps 10 MW.But this value is yet too low regarding parameters which land and space used being maximized but with low efficiency.So competition with HAWT does not look probable.

           

          PierreB




          > Message du 27/10/13 20:30
          > De : "Pierre BENHAIEM"
          > A : AirborneWindEnergy@yahoogroups.com
          > Copie à :
          > Objet : re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
          >
          >  

          >

          > Thank you DaveS,

          >  

          > Swept area is only the projection (low value since the kite flies with low incidence at the top) of arch on a perpendicular plan face to wind,comprising the (low) amplitude of oscillations.So an arch of 1 km/0.2 km (200,000 m²) will have a swept area around 100,000 m²,probably far less.Oscillations can be divided in a power phase downwind,and a recovering phase (the same for yoyo) here due to the elasticity of material.In an old post DaveL indicates a value of roughly 15% of the whole or on Betz'limit (I dont remember) for drag power.The recovering phase "eats" some energy and half of time.So 6% could be an optimist value.With wind speed = 10 m/s,the power is something like 6 MW. Adding replacement of blue tarp each 6 months (by being very optimist). Price of blue tarp 1$/m².For 20 years the expense of blue tarp is 8,000,000 $, far more than blades for a 6 MW conventional wind turbine.Adding orientation face to the winds (not possible for an arch with two anchors), maintenance (which working for replacement of blue tarp), management,etc.

          > PierreB

          > Message du 27/10/13 19:03
          > > De : "dave santos"
          > > A : "AWE"
          > > Copie à : "Roland Schmehl" , "jeroenbreukels@..."
          > > Objet : [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
          > >
          > >  

          > >

          This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software "toolbox" was still only partly developed. The dynamic force vectors are nicely animated. Concurrent wind-tunnel testing with staked-out wings also necessarily omitted tethers. Open-source AWE was able to see in this work a wonderful unintended result, the first numeric simulation and scale windtunnel testing of a mega-arch kite fixed crosswind, clearly displaying empirically well-known but unformalized kite dynamics (phugoid and dutch-roll mixed-modes). 

          > >
          A kPower working conjecture is these dynamics can work at the kilometer gigawatt unit-scale to pump groundgens by passive oscillations. The scaled-up arch kites proposed would be of megascale rope load-path and membrane kixel construction. Operational, physical, and design similarity cases include mega-scale trawl-nets and sports-field-tarp handling. A 300m2 flight demonstrator (Mothra1, 2012) met every design expectation and far larger kites are in planning. Critique and suggestions invited.
           
           
           
          A link as requested by MikeB and PierreB (sorry for the delay)-
          > >
          > >
        • Rod Read
          Pierre, The arches (& meshed arch networks) I m looking to test will implement mixes of mass grouped panel aspect adjustments , independent bilateral variable
          Message 4 of 8 , Oct 27, 2013
            Pierre,
            The arches (& meshed arch networks) I'm looking to test will implement mixes of

            mass grouped panel aspect adjustments ,

            independent bilateral variable geometry (probably pulled from a low, driven line riding "body"

            some right sexy lookin power pulling moves.

            more rope.


            Rod Read

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

            07899057227
            01851 870878



            On 27 October 2013 20:06, Pierre BENHAIEM <pierre.benhaiem@...> wrote:
             

            A part of the arch can work "crosswind",but not at high speed,due to the own limits of the arch.So the power could be more,perhaps 10 MW.But this value is yet too low regarding parameters which land and space used being maximized but with low efficiency.So competition with HAWT does not look probable.

             

            PierreB




            > Message du 27/10/13 20:30
            > De : "Pierre BENHAIEM"
            > A : AirborneWindEnergy@yahoogroups.com
            > Copie à :
            > Objet : re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)

            >
            >  

            >

            > Thank you DaveS,

            >  

            > Swept area is only the projection (low value since the kite flies with low incidence at the top) of arch on a perpendicular plan face to wind,comprising the (low) amplitude of oscillations.So an arch of 1 km/0.2 km (200,000 m²) will have a swept area around 100,000 m²,probably far less.Oscillations can be divided in a power phase downwind,and a recovering phase (the same for yoyo) here due to the elasticity of material.In an old post DaveL indicates a value of roughly 15% of the whole or on Betz'limit (I dont remember) for drag power.The recovering phase "eats" some energy and half of time.So 6% could be an optimist value.With wind speed = 10 m/s,the power is something like 6 MW. Adding replacement of blue tarp each 6 months (by being very optimist). Price of blue tarp 1$/m².For 20 years the expense of blue tarp is 8,000,000 $, far more than blades for a 6 MW conventional wind turbine.Adding orientation face to the winds (not possible for an arch with two anchors), maintenance (which working for replacement of blue tarp), management,etc.

            > PierreB

            > Message du 27/10/13 19:03
            > > De : "dave santos"
            > > A : "AWE"
            > > Copie à : "Roland Schmehl" , "jeroenbreukels@..."
            > > Objet : [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
            > >
            > >  

            > >

            This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software "toolbox" was still only partly developed. The dynamic force vectors are nicely animated. Concurrent wind-tunnel testing with staked-out wings also necessarily omitted tethers. Open-source AWE was able to see in this work a wonderful unintended result, the first numeric simulation and scale windtunnel testing of a mega-arch kite fixed crosswind, clearly displaying empirically well-known but unformalized kite dynamics (phugoid and dutch-roll mixed-modes). 

            > >
            A kPower working conjecture is these dynamics can work at the kilometer gigawatt unit-scale to pump groundgens by passive oscillations. The scaled-up arch kites proposed would be of megascale rope load-path and membrane kixel construction. Operational, physical, and design similarity cases include mega-scale trawl-nets and sports-field-tarp handling. A 300m2 flight demonstrator (Mothra1, 2012) met every design expectation and far larger kites are in planning. Critique and suggestions invited.
             
             
             
            A link as requested by MikeB and PierreB (sorry for the delay)-
            > >
            > >


          • dave santos
            Pierre, Blue-tarps, as clearly explained before, are only for cheapest DIY, but they would have a very fast payback. It was Dave Culp who said to try tarps
            Message 5 of 8 , Oct 27, 2013

              Pierre,

              Blue-tarps, as clearly explained before, are only for cheapest DIY, but they would have a very fast payback. It was Dave Culp who said to try tarps (he believes in testing, not guessing). You misunderstand our logic (to actually try "everything"). We have yet to destroy or wear-out a single tarp, despite many deliberate abuses. Never forget that we are really master kitemakers, just like you saw in Dieppe, and we know and use the best materials. See old posts regarding the amazing life of modern kite fabric (esp. Peter Lynn's SkySilk testing).

              Similarly, do not be too hasty in your assumptions and calculations (which are sometimes very problematic). You did not even suspect until now that kite arches had inherent dynamic force modes (!), nor do you at all account for many complex effects (like invisible "added mass" of entrained flow). Keep an open mind: Your rigid pessimism against all megascale schemes, except your own, is very troubling. In fact there are many promising megascale approaches to carefully test. Important advice to you, if your schemes are to keep-up, is to fly all kinds of kites, as much as your can; and create small working prototypes of your ideas. We can then help improve the results.

              Note also that the idea of hoisting existing turbines under an arch was just a small intermediate proof step that a kite arch can in fact enable megascale AWES; for you to allow as a bare logical possibility only, before moving the logical argument to its hopeful conclusion (that arches can work in AWE) based on future specialized WECS carefully optimized for highest power-to-weight and power-to-area, in AWES roles,

              daveS



              On Sunday, October 27, 2013 1:06 PM, Pierre BENHAIEM <pierre.benhaiem@...> wrote:
               
              A part of the arch can work "crosswind",but not at high speed,due to the own limits of the arch.So the power could be more,perhaps 10 MW.But this value is yet too low regarding parameters which land and space used being maximized but with low efficiency.So competition with HAWT does not look probable.
               
              PierreB




              > Message du 27/10/13 20:30
              > De : "Pierre BENHAIEM"
              > A : AirborneWindEnergy@yahoogroups.com
              > Copie à :
              > Objet : re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
              >
              >  
              >
              > Thank you DaveS,
              >  
              > Swept area is only the projection (low value since the kite flies with low incidence at the top) of arch on a perpendicular plan face to wind,comprising the (low) amplitude of oscillations.So an arch of 1 km/0.2 km (200,000 m²) will have a swept area around 100,000 m²,probably far less.Oscillations can be divided in a power phase downwind,and a recovering phase (the same for yoyo) here due to the elasticity of material.In an old post DaveL indicates a value of roughly 15% of the whole or on Betz'limit (I dont remember) for drag power.The recovering phase "eats" some energy and half of time.So 6% could be an optimist value.With wind speed = 10 m/s,the power is something like 6 MW. Adding replacement of blue tarp each 6 months (by being very optimist). Price of blue tarp 1$/m².For 20 years the expense of blue tarp is 8,000,000 $, far more than blades for a 6 MW conventional wind turbine.Adding orientation face to the winds (not possible for an arch with two anchors), maintenance (which working for replacement of blue tarp), management,etc.
              > PierreB
              > Message du 27/10/13 19:03
              > > De : "dave santos"
              > > A : "AWE"
              > > Copie à : "Roland Schmehl" , "jeroenbreukels@..."
              > > Objet : [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
              > >
              > >  
              > >
              This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software "toolbox" was still only partly developed. The dynamic force vectors are nicely animated. Concurrent wind-tunnel testing with staked-out wings also necessarily omitted tethers. Open-source AWE was able to see in this work a wonderful unintended result, the first numeric simulation and scale windtunnel testing of a mega-arch kite fixed crosswind, clearly displaying empirically well-known but unformalized kite dynamics (phugoid and dutch-roll mixed-modes). 

              > >
              A kPower working conjecture is these dynamics can work at the kilometer gigawatt unit-scale to pump groundgens by passive oscillations. The scaled-up arch kites proposed would be of megascale rope load-path and membrane kixel construction. Operational, physical, and design similarity cases include mega-scale trawl-nets and sports-field-tarp handling. A 300m2 flight demonstrator (Mothra1, 2012) met every design expectation and far larger kites are in planning. Critique and suggestions invited.
               
               
               
              A link as requested by MikeB and PierreB (sorry for the delay)-
              > >
              > >


            • Pierre BENHAIEM
              DaveS, Similarly, do not be too hasty in your assumptions and calculations (which are sometimes very problematic). Please provide your own calculations and
              Message 6 of 8 , Oct 27, 2013

                DaveS,

                 

                "Similarly, do not be too hasty in your assumptions and calculations (which are sometimes very problematic)."

                 

                Please provide your own calculations and descriptions.

                 

                PierreB




                > Message du 27/10/13 22:42
                > De : "dave santos"
                > A : "AirborneWindEnergy@yahoogroups.com"
                > Copie à :
                > Objet : Re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                >
                >  

                >


                >
                 
                Pierre,

                >
                Blue-tarps, as clearly explained before, are only for cheapest DIY, but they would have a very fast payback. It was Dave Culp who said to try tarps (he believes in testing, not guessing). You misunderstand our logic (to actually try "everything"). We have yet to destroy or wear-out a single tarp, despite many deliberate abuses. Never forget that we are really master kitemakers, just like you saw in Dieppe, and we know and use the best materials. See old posts regarding the amazing life of modern kite fabric (esp. Peter Lynn's SkySilk testing).

                >
                Similarly, do not be too hasty in your assumptions and calculations (which are sometimes very problematic). You did not even suspect until now that kite arches had inherent dynamic force modes (!), nor do you at all account for many complex effects (like invisible "added mass" of entrained flow). Keep an open mind: Your rigid pessimism against all megascale schemes, except your own, is very troubling. In fact there are many promising megascale approaches to carefully test. Important advice to you, if your schemes are to keep-up, is to fly all kinds of kites, as much as your can; and create small working prototypes of your ideas. We can then help improve the results.

                >
                Note also that the idea of hoisting existing turbines under an arch was just a small intermediate proof step that a kite arch can in fact enable megascale AWES; for you to allow as a bare logical possibility only, before moving the logical argument to its hopeful conclusion (that arches can work in AWE) based on future specialized WECS carefully optimized for highest power-to-weight and power-to-area, in AWES roles,
                 

                > daveS
                >

                >

                >
                >
                On Sunday, October 27, 2013 1:06 PM, Pierre BENHAIEM wrote:
                >
                 
                A part of the arch can work "crosswind",but not at high speed,due to the own limits of the arch.So the power could be more,perhaps 10 MW.But this value is yet too low regarding parameters which land and space used being maximized but with low efficiency.So competition with HAWT does not look probable.
                 
                PierreB




                > Message du 27/10/13 20:30
                > De : "Pierre BENHAIEM"
                > A : AirborneWindEnergy@yahoogroups.com
                > Copie à :
                > Objet : re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                >
                >  
                >
                > Thank you DaveS,
                >  
                > Swept area is only the projection (low value since the kite flies with low incidence at the top) of arch on a perpendicular plan face to wind,comprising the (low) amplitude of oscillations.So an arch of 1 km/0.2 km (200,000 m²) will have a swept area around 100,000 m²,probably far less.Oscillations can be divided in a power phase downwind,and a recovering phase (the same for yoyo) here due to the elasticity of material.In an old post DaveL indicates a value of roughly 15% of the whole or on Betz'limit (I dont remember) for drag power.The recovering phase "eats" some energy and half of time.So 6% could be an optimist value.With wind speed = 10 m/s,the power is something like 6 MW. Adding replacement of blue tarp each 6 months (by being very optimist). Price of blue tarp 1$/m².For 20 years the expense of blue tarp is 8,000,000 $, far more than blades for a 6 MW conventional wind turbine.Adding orientation face to the winds (not possible for an arch with two anchors), maintenance (which working for replacement of blue tarp), management,etc.
                > PierreB
                > Message du 27/10/13 19:03
                > > De : "dave santos"
                > > A : "AWE"
                > > Copie à : "Roland Schmehl" , "jeroenbreukels@..."
                > > Objet : [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                > >
                > >  
                > >
                This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software "toolbox" was still only partly developed. The dynamic force vectors are nicely animated. Concurrent wind-tunnel testing with staked-out wings also necessarily omitted tethers. Open-source AWE was able to see in this work a wonderful unintended result, the first numeric simulation and scale windtunnel testing of a mega-arch kite fixed crosswind, clearly displaying empirically well-known but unformalized kite dynamics (phugoid and dutch-roll mixed-modes). 

                > >
                A kPower working conjecture is these dynamics can work at the kilometer gigawatt unit-scale to pump groundgens by passive oscillations. The scaled-up arch kites proposed would be of megascale rope load-path and membrane kixel construction. Operational, physical, and design similarity cases include mega-scale trawl-nets and sports-field-tarp handling. A 300m2 flight demonstrator (Mothra1, 2012) met every design expectation and far larger kites are in planning. Critique and suggestions invited.
                 
                 
                 
                A link as requested by MikeB and PierreB (sorry for the delay)-
                > >
                > >
                 

                >
                >
              • dave santos
                Pierre asked: Please provide your own calculations and descriptions. (regarding arch power and dynamics). I do Pierre, but you seem to miss them. Did you
                Message 7 of 8 , Oct 27, 2013

                  Pierre asked: "Please provide your own calculations and descriptions." (regarding arch power and dynamics).

                  I do Pierre, but you seem to miss them. Did you follow my recent posts regarding dimensionless crosswind-stability and wing-loading spectrum numbers? I do many AWES descriptions, plus many photos and videos of real flying demos. Please count this work. Keep in mind the use of TUDelft work to support kite arch theses is third-party, far better than just me making isolated claims.

                  If you can do as well for your curious offshore AWES concept, I will not complain.










                  On Sunday, October 27, 2013 3:58 PM, Pierre BENHAIEM <pierre.benhaiem@...> wrote:
                   
                  DaveS,
                   
                  "Similarly, do not be too hasty in your assumptions and calculations (which are sometimes very problematic)."
                   
                  Please provide your own calculations and descriptions.
                   
                  PierreB




                  > Message du 27/10/13 22:42
                  > De : "dave santos"
                  > A : "AirborneWindEnergy@yahoogroups.com"
                  > Copie à :
                  > Objet : Re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                  >
                  >  
                  >

                  >
                   
                  Pierre,

                  >
                  Blue-tarps, as clearly explained before, are only for cheapest DIY, but they would have a very fast payback. It was Dave Culp who said to try tarps (he believes in testing, not guessing). You misunderstand our logic (to actually try "everything"). We have yet to destroy or wear-out a single tarp, despite many deliberate abuses. Never forget that we are really master kitemakers, just like you saw in Dieppe, and we know and use the best materials. See old posts regarding the amazing life of modern kite fabric (esp. Peter Lynn's SkySilk testing).

                  >
                  Similarly, do not be too hasty in your assumptions and calculations (which are sometimes very problematic). You did not even suspect until now that kite arches had inherent dynamic force modes (!), nor do you at all account for many complex effects (like invisible "added mass" of entrained flow). Keep an open mind: Your rigid pessimism against all megascale schemes, except your own, is very troubling. In fact there are many promising megascale approaches to carefully test. Important advice to you, if your schemes are to keep-up, is to fly all kinds of kites, as much as your can; and create small working prototypes of your ideas. We can then help improve the results.

                  >
                  Note also that the idea of hoisting existing turbines under an arch was just a small intermediate proof step that a kite arch can in fact enable megascale AWES; for you to allow as a bare logical possibility only, before moving the logical argument to its hopeful conclusion (that arches can work in AWE) based on future specialized WECS carefully optimized for highest power-to-weight and power-to-area, in AWES roles,
                   

                  > daveS
                  >

                  >

                  >
                  >
                  On Sunday, October 27, 2013 1:06 PM, Pierre BENHAIEM wrote:
                  >
                   
                  A part of the arch can work "crosswind",but not at high speed,due to the own limits of the arch.So the power could be more,perhaps 10 MW.But this value is yet too low regarding parameters which land and space used being maximized but with low efficiency.So competition with HAWT does not look probable.
                   
                  PierreB




                  > Message du 27/10/13 20:30
                  > De : "Pierre BENHAIEM"
                  > A : AirborneWindEnergy@yahoogroups.com
                  > Copie à :
                  > Objet : re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                  >
                  >  
                  >
                  > Thank you DaveS,
                  >  
                  > Swept area is only the projection (low value since the kite flies with low incidence at the top) of arch on a perpendicular plan face to wind,comprising the (low) amplitude of oscillations.So an arch of 1 km/0.2 km (200,000 m²) will have a swept area around 100,000 m²,probably far less.Oscillations can be divided in a power phase downwind,and a recovering phase (the same for yoyo) here due to the elasticity of material.In an old post DaveL indicates a value of roughly 15% of the whole or on Betz'limit (I dont remember) for drag power.The recovering phase "eats" some energy and half of time.So 6% could be an optimist value.With wind speed = 10 m/s,the power is something like 6 MW. Adding replacement of blue tarp each 6 months (by being very optimist). Price of blue tarp 1$/m².For 20 years the expense of blue tarp is 8,000,000 $, far more than blades for a 6 MW conventional wind turbine.Adding orientation face to the winds (not possible for an arch with two anchors), maintenance (which working for replacement of blue tarp), management,etc.
                  > PierreB
                  > Message du 27/10/13 19:03
                  > > De : "dave santos"
                  > > A : "AWE"
                  > > Copie à : "Roland Schmehl" , "jeroenbreukels@..."
                  > > Objet : [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                  > >
                  > >  
                  > >
                  This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software "toolbox" was still only partly developed. The dynamic force vectors are nicely animated. Concurrent wind-tunnel testing with staked-out wings also necessarily omitted tethers. Open-source AWE was able to see in this work a wonderful unintended result, the first numeric simulation and scale windtunnel testing of a mega-arch kite fixed crosswind, clearly displaying empirically well-known but unformalized kite dynamics (phugoid and dutch-roll mixed-modes). 

                  > >
                  A kPower working conjecture is these dynamics can work at the kilometer gigawatt unit-scale to pump groundgens by passive oscillations. The scaled-up arch kites proposed would be of megascale rope load-path and membrane kixel construction. Operational, physical, and design similarity cases include mega-scale trawl-nets and sports-field-tarp handling. A 300m2 flight demonstrator (Mothra1, 2012) met every design expectation and far larger kites are in planning. Critique and suggestions invited.
                   
                   
                   
                  A link as requested by MikeB and PierreB (sorry for the delay)-
                  > >
                  > >
                   

                  >
                  >


                • Pierre BENHAIEM
                  DaveS, If you can do as well for your curious offshore AWES concept, I will not complain. AWE searches are not a game for childs telling: if you dont like my
                  Message 8 of 8 , Oct 27, 2013

                    DaveS,

                     

                    "If you can do as well for your curious offshore AWES concept, I will not complain."

                     

                    AWE searches are not a game for childs telling:"if you dont like my AWE,I will not like yours."

                    I try to examine some aspects of different system until a possible answer.

                     

                    PierreB



                    > Message du 28/10/13 05:04
                    > De : "dave santos"
                    > A : "AirborneWindEnergy@yahoogroups.com"
                    > Copie à :
                    > Objet : Re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                    >
                    >  

                    >


                    >
                     
                    Pierre asked: "Please provide your own calculations and descriptions." (regarding arch power and dynamics).

                    >
                    I do Pierre, but you seem to miss them. Did you follow my recent posts regarding dimensionless crosswind-stability and wing-loading spectrum numbers? I do many AWES descriptions, plus many photos and videos of real flying demos. Please count this work. Keep in mind the use of TUDelft work to support kite arch theses is third-party, far better than just me making isolated claims.

                    >
                    If you can do as well for your curious offshore AWES concept, I will not complain.

                    >

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                    On Sunday, October 27, 2013 3:58 PM, Pierre BENHAIEM wrote:
                    >
                     
                    DaveS,
                     
                    "Similarly, do not be too hasty in your assumptions and calculations (which are sometimes very problematic)."
                     
                    Please provide your own calculations and descriptions.
                     
                    PierreB




                    > Message du 27/10/13 22:42
                    > De : "dave santos"
                    > A : "AirborneWindEnergy@yahoogroups.com"
                    > Copie à :
                    > Objet : Re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                    >
                    >  
                    >

                    >
                     
                    Pierre,

                    >
                    Blue-tarps, as clearly explained before, are only for cheapest DIY, but they would have a very fast payback. It was Dave Culp who said to try tarps (he believes in testing, not guessing). You misunderstand our logic (to actually try "everything"). We have yet to destroy or wear-out a single tarp, despite many deliberate abuses. Never forget that we are really master kitemakers, just like you saw in Dieppe, and we know and use the best materials. See old posts regarding the amazing life of modern kite fabric (esp. Peter Lynn's SkySilk testing).

                    >
                    Similarly, do not be too hasty in your assumptions and calculations (which are sometimes very problematic). You did not even suspect until now that kite arches had inherent dynamic force modes (!), nor do you at all account for many complex effects (like invisible "added mass" of entrained flow). Keep an open mind: Your rigid pessimism against all megascale schemes, except your own, is very troubling. In fact there are many promising megascale approaches to carefully test. Important advice to you, if your schemes are to keep-up, is to fly all kinds of kites, as much as your can; and create small working prototypes of your ideas. We can then help improve the results.

                    >
                    Note also that the idea of hoisting existing turbines under an arch was just a small intermediate proof step that a kite arch can in fact enable megascale AWES; for you to allow as a bare logical possibility only, before moving the logical argument to its hopeful conclusion (that arches can work in AWE) based on future specialized WECS carefully optimized for highest power-to-weight and power-to-area, in AWES roles,
                     

                    > daveS
                    >

                    >

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                    On Sunday, October 27, 2013 1:06 PM, Pierre BENHAIEM wrote:
                    >
                     
                    A part of the arch can work "crosswind",but not at high speed,due to the own limits of the arch.So the power could be more,perhaps 10 MW.But this value is yet too low regarding parameters which land and space used being maximized but with low efficiency.So competition with HAWT does not look probable.
                     
                    PierreB




                    > Message du 27/10/13 20:30
                    > De : "Pierre BENHAIEM"
                    > A : AirborneWindEnergy@yahoogroups.com
                    > Copie à :
                    > Objet : re: [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                    >
                    >  
                    >
                    > Thank you DaveS,
                    >  
                    > Swept area is only the projection (low value since the kite flies with low incidence at the top) of arch on a perpendicular plan face to wind,comprising the (low) amplitude of oscillations.So an arch of 1 km/0.2 km (200,000 m²) will have a swept area around 100,000 m²,probably far less.Oscillations can be divided in a power phase downwind,and a recovering phase (the same for yoyo) here due to the elasticity of material.In an old post DaveL indicates a value of roughly 15% of the whole or on Betz'limit (I dont remember) for drag power.The recovering phase "eats" some energy and half of time.So 6% could be an optimist value.With wind speed = 10 m/s,the power is something like 6 MW. Adding replacement of blue tarp each 6 months (by being very optimist). Price of blue tarp 1$/m².For 20 years the expense of blue tarp is 8,000,000 $, far more than blades for a 6 MW conventional wind turbine.Adding orientation face to the winds (not possible for an arch with two anchors), maintenance (which working for replacement of blue tarp), management,etc.
                    > PierreB
                    > Message du 27/10/13 19:03
                    > > De : "dave santos"
                    > > A : "AWE"
                    > > Copie à : "Roland Schmehl" , "jeroenbreukels@..."
                    > > Objet : [AWES] Link to Arched Kite Aeroelastic Simulation (attn. MikeB, PierreB, and ASSET)
                    > >
                    > >  
                    > >
                    This cool kite simulation linked below, by JeorenB [TUDelft], was performed without tethers, as his early kite software "toolbox" was still only partly developed. The dynamic force vectors are nicely animated. Concurrent wind-tunnel testing with staked-out wings also necessarily omitted tethers. Open-source AWE was able to see in this work a wonderful unintended result, the first numeric simulation and scale windtunnel testing of a mega-arch kite fixed crosswind, clearly displaying empirically well-known but unformalized kite dynamics (phugoid and dutch-roll mixed-modes). 

                    > >
                    A kPower working conjecture is these dynamics can work at the kilometer gigawatt unit-scale to pump groundgens by passive oscillations. The scaled-up arch kites proposed would be of megascale rope load-path and membrane kixel construction. Operational, physical, and design similarity cases include mega-scale trawl-nets and sports-field-tarp handling. A 300m2 flight demonstrator (Mothra1, 2012) met every design expectation and far larger kites are in planning. Critique and suggestions invited.
                     
                     
                     
                    A link as requested by MikeB and PierreB (sorry for the delay)-
                    > >
                    > >
                     

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