[FRIAM] flocking windmills
A golden oldie for you all. Just about this time in 2009 we discussed the possibility that vertical axis wind turbines could be organised as schools of fish to boost efficiency as a flock. Peter Lissaman was not amused. It turns out that the physicist who proposed the idea won a MacArthur fellowship in 2010 -- http://www.macfound.org/fellows/30/ -- but the idea hasn't really panned out. According to http://www.gizmag.com/dabiri-fish-school-wind-farms/28355/ there can be efficiency gains and there can be density advantages, but the arguments are not especially overwhelming. -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com
Re: [FRIAM] flocking windmills
Roger Critchlow wrote: Well, I better keep my voodoo fluid dynamics speculations to myself in the future. Nah. The venue for objection was the APS meeting in Minneapolis... FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills
It looks to me the article addresses this. When windmills are in a conventional face to the wind position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning sideways, they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a vertical rotation. The photo shows vertically rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - From: Nicholas Thompson To: Carl Tollander Cc: Friam@redfish.com Sent: Tuesday, November 24, 2009 9:45 PM Subject: Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, Wait a blithering moment!!!, suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to feel the headwind? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, I am a wind turbine, the group has determined that it will be most efficient if you place me over there. And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines want some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 7:36:30 PM Subject: [FRIAM] flocking windmills Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills
...that should read rotate the position of the fans 90 degrees (it was late and I should have been in bed). - Original Message - From: Hugh Trenchard To: nickthomp...@earthlink.net ; The Friday Morning Applied Complexity Coffee Group ; Carl Tollander Cc: Friam@redfish.com Sent: Wednesday, November 25, 2009 12:05 AM Subject: Re: [FRIAM] flocking windmills It looks to me the article addresses this. When windmills are in a conventional face to the wind position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning sideways, they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a vertical rotation. The photo shows vertically rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - From: Nicholas Thompson To: Carl Tollander Cc: Friam@redfish.com Sent: Tuesday, November 24, 2009 9:45 PM Subject: Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, Wait a blithering moment!!!, suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to feel the headwind? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, I am a wind turbine, the group has determined that it will be most efficient if you place me over there. And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines want some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 7:36:30 PM Subject: [FRIAM] flocking windmills Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills
Hugh, Thanks for explaining this to me. I figured it was something like that. But the logic IS backwards with respect to the bike racer model. The Bike racer pod is trying to protect the lead racer from wind resistance, the wind mills are trying to pass that resistance through to ever member of the pod. We could shrink-wrap the bike-pod, and it would do its job even better. Not so the windmill pod. Right? N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Hugh Trenchard To: The Friday Morning Applied Complexity Coffee Group;nickthomp...@earthlink.net;Carl Tollander Cc: Friam@redfish.com Sent: 11/25/2009 7:15:27 AM Subject: Re: [FRIAM] flocking windmills ...that should read rotate the position of the fans 90 degrees (it was late and I should have been in bed). - Original Message - From: Hugh Trenchard To: nickthomp...@earthlink.net ; The Friday Morning Applied Complexity Coffee Group ; Carl Tollander Cc: Friam@redfish.com Sent: Wednesday, November 25, 2009 12:05 AM Subject: Re: [FRIAM] flocking windmills It looks to me the article addresses this. When windmills are in a conventional face to the wind position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning sideways, they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a vertical rotation. The photo shows vertically rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - From: Nicholas Thompson To: Carl Tollander Cc: Friam@redfish.com Sent: Tuesday, November 24, 2009 9:45 PM Subject: Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, Wait a blithering moment!!!, suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to feel the headwind? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, I am a wind turbine, the group has determined that it will be most efficient if you place me over there. And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines want some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 7:36:30 PM Subject: [FRIAM] flocking windmills Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv
Re: [FRIAM] flocking windmills
No, the pelaton uses the lead rider to break a bow wave through the air, but the eddies from each rider's passage also curl around to give some lift to the subsequent riders in the pelaton. If you smoothed it out into one long cylinder, it wouldn't work as well. The vertical wind turbines work as a flock because they induce a sort of do-si-do of the wind through the flock, where each rank of turbines is positioned to catch the eddy from the preceding rank and throw it back to the next rank. Because the wind takes a longer than straight path through the flock, it has to move faster than the unimpeded wind. If you just set up a stonehenge in the same arrangement as the flock of turbines, you'd get the same sort of velocity effect. Having the flock adjust its geometry could be a big win. A fixed installation would be tuned to the most likely wind speed and direction. -- rec -- On Wed, Nov 25, 2009 at 9:58 AM, Nicholas Thompson nickthomp...@earthlink.net wrote: Hugh, Thanks for explaining this to me. I figured it was something like that. But the logic IS backwards with respect to the bike racer model. The Bike racer pod is trying to protect the lead racer from wind resistance, the wind mills are trying to pass that resistance through to ever member of the pod. We could shrink-wrap the bike-pod, and it would do its job even better. Not so the windmill pod. Right? N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - *From:* Hugh Trenchard htrench...@shaw.ca *To: *The Friday Morning Applied Complexity Coffee Groupfriam@redfish.com ;nickthomp...@earthlink.net;Carl Tollander c...@plektyx.com *Cc: *fr...@redfish.com *Sent:* 11/25/2009 7:15:27 AM *Subject:* Re: [FRIAM] flocking windmills ...that should read rotate the position of the fans 90 degrees (it was late and I should have been in bed). - Original Message - *From:* Hugh Trenchard htrench...@shaw.ca *To:* nickthomp...@earthlink.net ; The Friday Morning Applied Complexity Coffee Group friam@redfish.com ; Carl Tollander c...@plektyx.com *Cc:* Friam@redfish.com *Sent:* Wednesday, November 25, 2009 12:05 AM *Subject:* Re: [FRIAM] flocking windmills It looks to me the article addresses this. When windmills are in a conventional face to the wind position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning sideways, they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a vertical rotation. The photo shows vertically rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - *From:* Nicholas Thompson nickthomp...@earthlink.net *To:* Carl Tollander c...@plektyx.com *Cc:* Friam@redfish.com *Sent:* Tuesday, November 24, 2009 9:45 PM *Subject:* Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, *Wait *a blithering moment!!!, suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to feel the headwind? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - *From:* Carl Tollander c...@plektyx.com *To: *nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group friam@redfish.com *Sent:* 11/24/2009 10:13:22 PM *Subject:* Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, I am a wind turbine, the group has determined that it will be most efficient if you place me over there. And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines want some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what
Re: [FRIAM] flocking windmills
Cyclists want lift??!! How do they maintain contact with the road? N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/25/2009 10:26:08 AM Subject: Re: [FRIAM] flocking windmills No, the pelaton uses the lead rider to break a bow wave through the air, but the eddies from each rider's passage also curl around to give some lift to the subsequent riders in the pelaton. If you smoothed it out into one long cylinder, it wouldn't work as well. The vertical wind turbines work as a flock because they induce a sort of do-si-do of the wind through the flock, where each rank of turbines is positioned to catch the eddy from the preceding rank and throw it back to the next rank. Because the wind takes a longer than straight path through the flock, it has to move faster than the unimpeded wind. If you just set up a stonehenge in the same arrangement as the flock of turbines, you'd get the same sort of velocity effect. Having the flock adjust its geometry could be a big win. A fixed installation would be tuned to the most likely wind speed and direction. -- rec -- On Wed, Nov 25, 2009 at 9:58 AM, Nicholas Thompson nickthomp...@earthlink.net wrote: Hugh, Thanks for explaining this to me. I figured it was something like that. But the logic IS backwards with respect to the bike racer model. The Bike racer pod is trying to protect the lead racer from wind resistance, the wind mills are trying to pass that resistance through to ever member of the pod. We could shrink-wrap the bike-pod, and it would do its job even better. Not so the windmill pod. Right? N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Hugh Trenchard To: The Friday Morning Applied Complexity Coffee Group;nickthomp...@earthlink.net;Carl Tollander Cc: Friam@redfish.com Sent: 11/25/2009 7:15:27 AM Subject: Re: [FRIAM] flocking windmills ...that should read rotate the position of the fans 90 degrees (it was late and I should have been in bed). - Original Message - From: Hugh Trenchard To: nickthomp...@earthlink.net ; The Friday Morning Applied Complexity Coffee Group ; Carl Tollander Cc: Friam@redfish.com Sent: Wednesday, November 25, 2009 12:05 AM Subject: Re: [FRIAM] flocking windmills It looks to me the article addresses this. When windmills are in a conventional face to the wind position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning sideways, they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a vertical rotation. The photo shows vertically rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - From: Nicholas Thompson To: Carl Tollander Cc: Friam@redfish.com Sent: Tuesday, November 24, 2009 9:45 PM Subject: Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, Wait a blithering moment!!!, suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to feel the headwind? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, I am a wind turbine, the group has determined that it will be most efficient if you place me over there. And the humans would go do that, since the turbine family was usually right about such things. So maybe
Re: [FRIAM] flocking windmills
Sorry for the confusion. it's sailor talk, a lift is an impulse in the direction you're trying to go. -- rec -- On Wed, Nov 25, 2009 at 10:43 AM, Nicholas Thompson nickthomp...@earthlink.net wrote: Cyclists want lift??!! How do they maintain contact with the road? N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - *From:* Roger Critchlow r...@elf.org *To: *nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group friam@redfish.com *Sent:* 11/25/2009 10:26:08 AM *Subject:* Re: [FRIAM] flocking windmills No, the pelaton uses the lead rider to break a bow wave through the air, but the eddies from each rider's passage also curl around to give some lift to the subsequent riders in the pelaton. If you smoothed it out into one long cylinder, it wouldn't work as well. The vertical wind turbines work as a flock because they induce a sort of do-si-do of the wind through the flock, where each rank of turbines is positioned to catch the eddy from the preceding rank and throw it back to the next rank. Because the wind takes a longer than straight path through the flock, it has to move faster than the unimpeded wind. If you just set up a stonehenge in the same arrangement as the flock of turbines, you'd get the same sort of velocity effect. Having the flock adjust its geometry could be a big win. A fixed installation would be tuned to the most likely wind speed and direction. -- rec -- On Wed, Nov 25, 2009 at 9:58 AM, Nicholas Thompson nickthomp...@earthlink.net wrote: Hugh, Thanks for explaining this to me. I figured it was something like that. But the logic IS backwards with respect to the bike racer model. The Bike racer pod is trying to protect the lead racer from wind resistance, the wind mills are trying to pass that resistance through to ever member of the pod. We could shrink-wrap the bike-pod, and it would do its job even better. Not so the windmill pod. Right? N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - *From:* Hugh Trenchard htrench...@shaw.ca *To: *The Friday Morning Applied Complexity Coffee Groupfriam@redfish.com ;nickthomp...@earthlink.net;Carl Tollander c...@plektyx.com *Cc: *fr...@redfish.com *Sent:* 11/25/2009 7:15:27 AM *Subject:* Re: [FRIAM] flocking windmills ...that should read rotate the position of the fans 90 degrees (it was late and I should have been in bed). - Original Message - *From:* Hugh Trenchard htrench...@shaw.ca *To:* nickthomp...@earthlink.net ; The Friday Morning Applied Complexity Coffee Group friam@redfish.com ; Carl Tollander c...@plektyx.com *Cc:* Friam@redfish.com *Sent:* Wednesday, November 25, 2009 12:05 AM *Subject:* Re: [FRIAM] flocking windmills It looks to me the article addresses this. When windmills are in a conventional face to the wind position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning sideways, they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a vertical rotation. The photo shows vertically rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - *From:* Nicholas Thompson nickthomp...@earthlink.net *To:* Carl Tollander c...@plektyx.com *Cc:* Friam@redfish.com *Sent:* Tuesday, November 24, 2009 9:45 PM *Subject:* Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, *Wait *a blithering moment!!!, suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to feel the headwind? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - *From:* Carl Tollander c...@plektyx.com *To: *nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group friam@redfish.com *Sent:* 11/24/2009 10:13:22 PM *Subject:* Re: [FRIAM] flocking windmills What they lack is mobility
Re: [FRIAM] flocking windmills
As others have already said, this is about Vertical Axis Wind Turbines (VAWT) rather than Horizontal Axis Wind Turbines (HAWT) like you see in eastern New Mexico and west Texas. The article is incorrect about VAWTs being a new idea - Sandia developed the idea in the '70s and you can see one of our surplused prototypes out at Clines Corner. VAWTs have three advantages - they are agnostic with respect to wind direction, the machinery is less complex as the turbine is at the bottom and there's no need for the machinery and complexity of the rotating head, and they can operate over a greater spread of windspeeds (HAWT are limited by the blade tip speed - if it exceeds the speed of sound they will break up). The reason HAWT have succeeded in the marketplace is that the blades can be lifted up into the best wind area - the Sandia egg-beater VAWTs are closer to the ground. The turbines in the article look like they beat that limitation by spinning around a tall mast. If I understand the article correctly, the concept of fish schooling formation undoes one of the benefits of VAWT - being agnostic with respect to wind direction. Ray Parks rcpa...@sandia.gov Consilient Heuristician Voice: 505-844-4024 ATA Department Mobile: 505-238-9359 http://www.sandia.gov/scada Fax: 505-844-9641 http://www.sandia.gov/idart Pager:505-951-6084 Roger Critchlow wrote: Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills
I've always wondered how sophisticated the algorithms for arranging windmills might be. A 0th-order one would seem to be to estimate the region where one windmill disturbs the airflow and avoid placing another in it. Another involves deferring to the topography (Tohachapi pass for example) and maximizing the ground-effects of air flowing over ridges, etc. It would seem that the problem should bend fairly well to computer simulation. My mother-in-law just signed over her 640 acre chunk of Northern Iowa, currently under cultivation for Soy, to be used for wind-farming (as well). There is not a place I know more flat than this land... I assume a large grid of windmills will sweep over the landscape with her 640 acres a tiny spot within the larger grid. Each windmill would seem to create a rough "cone" of disturbance leeward. That "cone" would probably consist of multiple scales of compression waves... it would seem that the natural period of the larger waves would be primarily a function of wind-speed while the structure of the turbine blades (blade pitch, width, length, cross-section) and the amount of resistance the blades(drag, bearing resistance, generator back-force, etc.) would inform the other structures. A simple euclidean grid would seem to be less than optimal, with a hexagonal grid (intuitively) seeming closest to optimal. One might imagine that freeing some assumed constraints might offer more opportunities for "tuning" such an array. Deliberately canting (in yaw) some of the mills relative to the wind might reduce their own effeciency to the gain of others "downwind" as might deliberately detuning the "pitch" (dynamically or statically.. at time of install/manufacture). Similarly, the height and pitch of the mill heads might be varied slightly over the array. One would expect some low order "standing waves" behind a single mill. Interesting (but distracting) question... How to tune a flock of windmills (statically, dynamically, ???). For many reasons, I expect wind "mills" to be replaced by something more like giant Cilia someday... maybe just for this very reason... that it should be easier to "tune" an array of such things than a bunch of "fans". Cilia-like energy extracting elements would seem suitable for hydro-power as well. You can tell I still love the "idea of" macro-engineering projects... but I'm pretty sure they are intrinsically bad for the health of the planet/humanity. - Steve It looks to me the article addresses this. When windmills are in a conventional "face to the wind" position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fansdegrees so that they are spinning "sideways", they spin with greater efficiency when lined up behind each otherinzones of lower air resistance. The article appears to refer to this fan position as a "vertical" rotation. The photo shows "vertically" rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - From: Nicholas Thompson To: Carl Tollander Cc: Friam@redfish.com Sent: Tuesday, November 24, 2009 9:45 PM Subject: Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, "Wait a blithering moment!!!", suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to "feel" the "headwind"? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, "I am a wind turbine, the group has determined that it will be most efficient if you place me over there." And the humans would go do th
Re: [FRIAM] flocking windmills
* * On Wed, Nov 25, 2009 at 1:52 PM, Steve Smith sasm...@swcp.com wrote: I've always wondered how sophisticated the algorithms for arranging windmills might be. Here's a micro-engineering variation to keep you out of macro-trouble. Now -- back into macro-trouble again -- if you had a flock of egg-beater generators on a piece of Iowa farmland, could you run them as mixers and give a tornado a leg up over the next town down wind? -- rec -- Synchronization and Collective Dynamics in a Carpet of Microfluidic Rotors. (arXiv:0911.4253v1 [cond-mat.soft]) http://arxiv.org/abs/0911.4253 from cond-mat.stat-mech updates on arXiv.org/reader/view/feed/http%3A%2F%2Farxiv.org%2Frss%2Fcond-mat.stat-mech by a href=http://arxiv.org/find/cond-mat/1/au:+Uchida_N/0/1/0/all/0/1;Nariya Uchida/a, a href= http://arxiv.org/find/cond-mat/1/au:+Golestanian_R/0/1/0/all/0/1;Ramin Golestanian/a We study synchronization of an *array* of rotors on a substrate that are coupled by hydrodynamic interaction. The rotors that are modeled by an effective rigid body, are driven by an internal torque and exerts an active force on the surrounding fluid. The long-ranged nature of the hydrodynamic interaction between the rotors causes a rich pattern of dynamical behaviors including phase ordering and turbulent spiral waves. The model provides a novel example of coupled oscillators with long-range interaction. Our results suggest strategies for designing controllable microfluidic mixers using the emergent behavior of hydrodynamically coupled active components. FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills - bike race model
My understanding of drafting in the peloton is that there is a low pressure area induced behind riders, meaning there is less air resistance to the riders following, and hence less energy is expended by riders following in low pressure areas (1,2). It's not lift, like it is in the bird vee formation (as Peter Lissaman points out). There has been some suggestion that the lead rider also benefits by a nudge from the rider behind who fills the low pressure zone (3), but this is disputed (4). So energy savings in pelotons is not strictly due to eddies either. Efficiencies in bicycle racing (ie. increasing speed for least possible power output) increase as the peloton becomes denser, because greater energy savings occur the closer a cyclist behind can get to the wheel in front (1,2,4). This must be balanced against the increased risk for collision cyclists undergo as peloton density increases. The notion of a shrink-wrapped peloton well describes the correlation between optimal peloton speed and density, and seems to me a better description than the eddie model Roger C is describing. The staggering of cyclists in a peloton is due to its dynamical nature and the necessity for cyclists to avoid collision, and not because it is the theoretical absolute optimal energy savings formation. That is to say that the maximum drafting benefit is directly behind others (excluding cross-winds for the moment) (1,4), which does not practically occur in a peloton (except in what I call a stretched phase, which I won't get into here). Rather, a dynamical arrowhead, rounded, or rotational effect to the peloton occurs at a certain power output threshold (which is within a narrow range for all riders) as riders rotate through positions at the front, each seeking to save energy by drafting; optimal collective output occurs during this phase (based on personal observation and analysis). I don't profess a good understanding of the eddy principles that Roger is describing in the windmill formation, but as I gather them, the principles he describes do not seem to closely describe the peloton formation, as you've pointed out. Also, unlike the static windmill formation, the peloton is a dynamical system, and so its collective output optimization also depends on the movements of the agents within the system as they respond to each other and environmental parameters. So, in that respect, the article may be a bit loose in referring to the peloton as an analog. However, it seems to me the main idea is that there is overall energy saved by a particular collective formation. Whether it's drafting or by creating eddies or by lift, the mechanism may be different, but these principles of energy savings allow for generalized flocking phenomena to occur in natural systems, which is, in general principle, what the windmill engineers are exploiting. Refs 1. Kyle C. 1979 Reduction of wind resistance and power output of racing cyclists and runners travelling in groups Ergonomics 22: 387-397; 2. McCole et al 1990 Energy expenditure during bicycling Journal of Applied Physiology 68: 748-753 3. Cycling Performance Tips. Excercise Physiology - Energy Requirements of Bicycling http://www.cptips.com/energy.htm 4. Olds, T. 1998 The mathematics of breaking away and chasing in cycling 77. Eur J App Phiol 492-497 - Original Message - From: Nicholas Thompson To: Roger Critchlow Cc: friam@redfish.com Sent: Wednesday, November 25, 2009 9:43 AM Subject: Re: [FRIAM] flocking windmills Cyclists want lift??!! How do they maintain contact with the road? N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/25/2009 10:26:08 AM Subject: Re: [FRIAM] flocking windmills No, the pelaton uses the lead rider to break a bow wave through the air, but the eddies from each rider's passage also curl around to give some lift to the subsequent riders in the pelaton. If you smoothed it out into one long cylinder, it wouldn't work as well. The vertical wind turbines work as a flock because they induce a sort of do-si-do of the wind through the flock, where each rank of turbines is positioned to catch the eddy from the preceding rank and throw it back to the next rank. Because the wind takes a longer than straight path through the flock, it has to move faster than the unimpeded wind. If you just set up a stonehenge in the same arrangement as the flock of turbines, you'd get the same sort of velocity effect. Having the flock adjust its geometry could be a big win. A fixed installation would be tuned to the most likely wind speed
Re: [FRIAM] flocking windmills
Well, I better keep my voodoo fluid dynamics speculations to myself in the future. Here's more information about the reported effect, written by someone who'd seen a vertical axis windmill before. http://physicsworld.com/cws/article/news/40993 The reason, they say, is that the presence of neighbouring turbines concentrates and accelerates the wind. The reports are all based off an oral presentation made Monday in Minneapolis at the annual meeting of the American Physical Society's Division of Fluid Dynamics. -- rec -- On Wed, Nov 25, 2009 at 2:32 PM, Marcus G. Daniels mar...@snoutfarm.comwrote: Roger Critchlow wrote: if you had a flock of egg-beater generators on a piece of Iowa farmland, could you run them as mixers and give a tornado a leg up over the next town down wind? Why should Iowa have all the fun? Howzabout making waterspouts with flocking tidal turbines? :-) FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
[FRIAM] flocking windmills
Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills
Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 7:36:30 PM Subject: [FRIAM] flocking windmills Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills
What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, "I am a wind turbine, the group has determined that it will be most efficient if you place me over there." And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines "want" some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 7:36:30 PM Subject: [FRIAM] flocking windmills Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills
Sorry, everybody. What I meant to write was, Wait a blithering moment!!!, suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to feel the headwind? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, I am a wind turbine, the group has determined that it will be most efficient if you place me over there. And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines want some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 7:36:30 PM Subject: [FRIAM] flocking windmills Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org