"The procedure is correct But a heluva mess, The Birdies Just Do it, And They could care less"
Adapted from Lissaman, 2007. By the way, I struggled for many minutes with "Interestingly, for a linear Vee, the wing at the apex of the Vee has the maximum saving. In 1971 I was in communication with ornithologists in Florida, who noted that their observations validated our Vee estimates and indicated that the apex position was usually taken by the older and more powerful birds. " I assume that the "wing at the apex of the the V" refers to the lead bird. Absent forward causality, this bird is the one that is flying in virgin air, no???? So this passage would imply that everybody else is flying with more or less of a disability. In which case, would it be better to fly alone? somebody straighten me out,here. nick > [Original Message] > From: <[EMAIL PROTECTED]> > To: <friam@redfish.com> > Date: 1/7/2007 12:00:16 PM > Subject: Friam Digest, Vol 43, Issue 9 > > Send Friam mailing list submissions to > friam@redfish.com > > To subscribe or unsubscribe via the World Wide Web, visit > http://redfish.com/mailman/listinfo/friam_redfish.com > or, via email, send a message with subject or body 'help' to > [EMAIL PROTECTED] > > You can reach the person managing the list at > [EMAIL PROTECTED] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Friam digest..." > > > Today's Topics: > > 1. Re: observations of complex phenomena while in Mexico > (Phil Henshaw) > 2. Re: Friam Digest, Vol 43, Issue 6 Formation Flight > (Peter Lissaman) > 3. Re: Friam Digest, Vol 43, Issue 6 Formation Flight > (Hugh Trenchard) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 07 Jan 2007 00:28:25 -0500 > From: "Phil Henshaw" <[EMAIL PROTECTED]> > Subject: Re: [FRIAM] observations of complex phenomena while in Mexico > To: "'The Friday Morning Applied Complexity Coffee Group'" > <friam@redfish.com> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=iso-8859-1 > > I'll be glad to see what further patterns you find. Just to clarify, my > suggestion was not just that the two colonies were different, but that > the variation in local colony behavior might be as great as the > variation in local environments where colonies are found. If you were > to make observations randomly across the range of the species you'd get > a better sense of what behaviors are universal and what are local. What > you'd want is a work-around, of course, that would be a little less > work. Perhaps you could try getting a list of bird watchers in the > frigatebird range and randomly calling them to see what they have to > say. > > As to the generality of a "drafting principle", there is at least one > major example of it I've given a good bit of study, the formation and > evolution of air currents. If you want an example of the vast > creativity of local physical processes you might do well to give them a > little look. Do all the modeling you like and none of it will produce > the degree of intricate and inventive complexity you find in the pathway > negotiations taking place around any even mildly warm body like, for > example, the one sitting in front of your computer screen right now! > > > Phil Henshaw ????.?? ? `?.???? > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 680 Ft. Washington Ave > NY NY 10040 > tel: 212-795-4844 > e-mail: [EMAIL PROTECTED] > explorations: www.synapse9.com > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Hugh Trenchard > > Sent: Saturday, January 06, 2007 7:16 PM > > To: The Friday Morning Applied Complexity Coffee Group > > Subject: Re: [FRIAM] observations of complex phenomena while in Mexico > > > > > > Thanks for all your comments. Next time I'm in Mexico, I will > > definitely do > > my best to get some video footage. My recollection of what I > > saw in October > > 2005 in Mazatlan is that the various yaws and compensations > > were easy to > > see, as you say. I can't remember how long the formations > > were stable - > > perhaps generally less than a minute, before the formation > > would break down > > (but I'm really just guessing) - but they were long enough to see the > > dynamics involved. And after the formations broke down, they > > would often > > reform again fairly soon. > > > > Regarding Phil's comment that the Mazatlan colonies were > > possibly just > > different from the Cancun colonies I will need to investigate that. > > (Frank - I was in Cancun over Christmas, by the way and the > > migration habits > > might be a factor involved in when and why they engage in vee > > formation - > > something else to investigate). It seems, though, it is > > unlikely that a > > single colony in Mazatlan would have developed the vee > > formation capacity > > completely independently of a colony in Cancun, especially > > when the distance > > between them is not really that great when we think in terms of bird > > migratory habits. So far, I still think the wind conditions > > are more likely > > what prevented vee formation in Cancun, but of course I will > > need a bit more > > evidence to support that. > > > > Also, Phil, I would argue that strong leadership is not a > > factor in vee > > formations. As we all know, self-organized phenomena arise > > without leaders > > to guide the emergent patterns - I can't think of why it would be any > > different for frigatebirds. The formations must self-organize > > from some > > principle of interaction - in the case of organisms that save > > energy by > > drafting, it is the coupling between them that occurs because > > there is a > > physiological or energetic advantage to their coupling (ie. to their > > drafting). > > > > It could be that frigatebird vee formations are simply > > derived from their > > inherent natural behaviours and have no basis in any > > underlying physical > > principles, but given the advantages conferred upon other > > types of organisms > > that engage in drafting dynamics and formations, it seems > > reasonable to ask > > if there is there is a physical principle underlying the formations. > > > > Nonetheless, what this all suggests to me that it is an area ripe for > > further study, and that very little work has been done to > > establish the > > universality of the "drafting principle" as I am calling it. > > I actually > > think it applies in a lot of other situations as well, from > > trail formation > > to aspects of economics, but that's little more than a gut > > feeling at this > > point. But I suppose, at the very least, until I can get > > some good footage > > of frigatebird formations and some wind speed measurements, > > we can only > > speculate as to what is happening with them. > > > > I'm not sure when I'll be in Mexico next, but I'll keep > > everyone posted as > > to what I see. If anyone else is going, please keep an eye > > out for the > > frigatebirds! Pelicans also fly in vees too, but they are > > more like geese, > > I think - they fly past at fairly high speed. > > > > On the note about the decline of traveling geese, I really > > can't speculate. > > I live on the west coast of Canada in British Columbia and I > > still see vee > > formations going in all directions. But perhaps global > > warming is a factor > > in the distances they need to fly now - maybe they can stay > > farther north > > all year round. > > > > Hugh Trenchard > > > > > > > > > > ------------------------------ > > Message: 2 > Date: Sat, 6 Jan 2007 22:47:57 -0700 > From: "Peter Lissaman" <[EMAIL PROTECTED]> > Subject: Re: [FRIAM] Friam Digest, Vol 43, Issue 6 Formation Flight > To: friam@redfish.com > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=US-ASCII > > In connections with the comments about FORMATION FLIGHT > > > FORMATION FLIGHT by PETER LISSAMAN > > The formation flight of birds has long been of interest to natural > scientists. Leonardo da Vinci discussed this in 1504, as did Lord Rayleigh > in 1889. The Vee formation produces significant energy saving. There is > no debate about this. It has been established unequivocally theoretically, > measured in flight tests with aircraft, and also, indirectly, in the > remotely monitored pulse rate of formations of our feathered friends, > actually Brown Pelicans. The mathematics is complicated. It relates to the > flows induced by the vortex wake behind a lifting wing. Outboard of the > wing a large upwash is induced, proportional to the circulation on the > wing, and the wing man (bird?), if he tucks up tight on the tip, is > flying in a strong upwash, with big drag savings. Thats all there is to > it! But, Ah, the Details! As Leonardo said "God is in the Details"! It > would be boring to go into those mathematics, except to say that the > procedure is considered well-understood and correct, but a helluva mess! > The birdies jus' do it, and could care less! > > The first paper I know of that treated the topic mathematically (and > brilliantly) was Wieselsberger in ZFM, 1914; and there has been a fairly > lively activity since then, as computers have removed the formidable and > intelligent math required, and made it possible for anyone to get results > without understanding them. In 1969 Carl Shollenberger, my valued friend > and colleague, and I worked on this, and published the results in Science. > The paper (Lissaman & Shollenberger, Formation Flight of Birds, Science, > Vol. 168, 1970) shows the very large size of these savings. We used the > impressive new IBM 360 computer at Caltech. It occupied a three storey > building about the size of a four unit apartment block, and had mens and > womens toilets inside, as well as 12 real people who punched cards, fed > data and generally dealt with the I/O. One picked up outputs at about > 3:00 am each night. My wife never really believed that was what kept me > up, although I did my thesis on mathematics of wing theory some years > before using that old 360! And used the same story! Computation is > clumsy, but more than Doktor Wieselsberger ever had! Carl was killed a few > years later, flying in night mountain turbulence over the Sierra Madres. > It was a great loss to aviation he was a fine pilot and aerodynamicist. > I acknowledge his contribution fondly. He would be glad that his work was > still used. Recently I revisited this subject in a paper Simplified > Analytical methods for Formation Flight (Lissaman, AIAA. Jan. 2005) and > next week will give a paper Neutral Energy Cycles for a Vehicle in > Sinusoidal and Turbulent Vertical Gusts (Lissaman & Patel, AIAA. Jan 2007) > > The Science paper shows that in theVee, for tight formations, one can > almost double the range for a given energy input. Also that there is a > stability mechanism, by which a member finds that moving ahead of the line > of the Vee requires power increases. So theres a comfortable groove to > fall into, which animals love! One should always be skeptical of > attributing effects derived from theoretical calculations to animal > behavior, but the general consensus of ornithologists and aerodynamicists > is that this Vee formation saving is so significant, and its application so > ubiquitous, that migrating birds DO use it to extend their range. The > paper addressed the savings for different positions in the Vee. In line > abreast, the center birds experience twice the saving of the tip members, > but if the tip members find this hard work and fall back to take advantage > of the increased favorable downstream upwash of the vortex wakes of the > inner members, then a balancing of savings occurs. We calculated the angle > of the Vee for equipartition. It is about the same as is observed with > migrating birds. We also showed that it was not necessary have equal legs > of the Vee. Provided there are at least about 6 birds on one side of the > Vee, the other leg can be almost as long as the birds choose to make it. > Interestingly, for a linear Vee, the wing at the apex of the Vee has the > maximum saving. In 1971 I was in communication with ornithologists in > Florida, who noted that their observations validated our Vee estimates and > indicated that the apex position was usually taken by the older and more > powerful birds. They wondered why the more powerful members of the flight > should take the easiest jobs! My answer was that most intelligent species > are pretty anthropomorphic! > > It may be noted that the savings are not related to drafting, that is > following behind a draggy object to take advantage of its lower dynamic > pressure wake. I am very familiar with this, and, as an automobile > aerodynamicist, have utilized this theory in race car design, and as is > obvious, the slingshot maneuver is very significant. But not in flight! It > is, in fact, horrible to fly directly astern of another flight vehicle, as > every pilot knows. Folks can, and do, get killed tangling with wake > vortices, as I know to my sadness, when an old friend and experienced Navy > pilot died as a consequence of following too close on final. > > Peter Lissaman, Da Vinci Ventures > > Expertise is not knowing everything, but knowing what to look for. > > 1454 Miracerros Loop South, Santa Fe, New Mexico 87505 > TEL: (505) 983-7728 FAX: (505) 983-1694 > > > > > > > ------------------------------ > > Message: 3 > Date: Sun, 07 Jan 2007 07:34:13 -0800 > From: Hugh Trenchard <[EMAIL PROTECTED]> > Subject: Re: [FRIAM] Friam Digest, Vol 43, Issue 6 Formation Flight > To: The Friday Morning Applied Complexity Coffee Group > <friam@redfish.com> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; format=flowed; charset=iso-8859-1; > reply-type=original > > Thank you for the interesting article - this listserv is proving to be a > wonderful resource! Thanks also for clarifying that energy savings in bird > flight formations involve different aerodynamics than drafting, which is an > important difference from my perspective. The key for me is still the > energy savings due to some positional zone where output is reduced, although > I may have call any universal phenomena in this respect something other than > a "drafting principle", which is what I was suggesting in my original note > on the subject. > > Have you made, or do you know of any studies that involve the dynamics of > frigatebirds? As I was noting, it appears to me that they align in vee > formations while gliding in relatively stationery positions. I was > suggesting this constitutes another type of "drafting", where the agents do > not create the air flow by moving through it, but attempt to remain as > motionless as possible in the face of air that is already moving (ie. > sufficiently high winds). If they are not flapping their wings, then does > this vee formation involve different aerodynamics from that of moving > pelicans or geese or others? > > Also, would you agree that fundamentally a similar phenomenon is occurring > as that which happens in penguin huddles - where penguins reduce heat loss > by close formations? > > In terms of the reason why stronger birds may take up easier positions in a > flight formation, I can actually offer a possible explanation on that. It's > based on my own observations of energy savings in bicycle pelotons (group of > cyclists riding together), and a equation I've developed with Gottfried > Mayer-Kress (formula not yet published though): > > PDR = (Pa - Pb / Pa) / D > > PDR is peloton disintegration ratio > > Pa is maximum power output of lead rider > Pb is max power output of drafting rider > D is energy savings due to drafting expressed as a percentage > Pa - Pb / Pa gives a percentage output difference > > So for example, rider A can put out a max of 450w at 40km/h when riding > solo, while rider B may be capable of a max of 330w for a max speed of > 30km/h when riding solo. But by drafting behind A, rider B can go 40km/h, > the same speed as A, while both are proceeding at their maximum outputs (B > saves 27 percent (Hagberg & McCole)). However, if rider C is capable of say > 470w for 41km/h, rider B would not be able to keep up. > > Applying this to birds, depending on how much stronger a lead bird is than a > following bird and how much energy is actually saved by following, it's > possible that stronger birds are actually so strong that even the energy > savings by flying in the zone of greatest savings is not enough to keep up > (PDR would be > 1, using my equation). > > So, what ends of happening is the strong birds ruin the flight formation - > so they end up with the luxury of sitting in, because they haven't learned > how to adjust their speed properly when they are the front to prevent > following birds from also hitting maximum and fatiguing too quickly. > > Just as a note, my primary interest is with the dynamics of bicycle > pelotons - I do not hold any special expertise, but am an amateur scientist, > as it were. I've made a number of observations of peloton dynamics, and am > still working on getting material published in the area. > > Hugh Trenchard > > ----- Original Message ----- > From: "Peter Lissaman" <[EMAIL PROTECTED]> > To: <friam@redfish.com> > Sent: Saturday, January 06, 2007 9:47 PM > Subject: Re: [FRIAM] Friam Digest, Vol 43, Issue 6 Formation Flight > > > > In connections with the comments about FORMATION FLIGHT > > > > > > FORMATION FLIGHT by PETER LISSAMAN > > > > The formation flight of birds has long been of interest to natural > > scientists. Leonardo da Vinci discussed this in 1504, as did Lord > > Rayleigh > > in 1889. The Vee formation produces significant energy saving. There is > > no debate about this. It has been established unequivocally > > theoretically, > > measured in flight tests with aircraft, and also, indirectly, in the > > remotely monitored pulse rate of formations of our feathered friends, > > actually Brown Pelicans. The mathematics is complicated. It relates to > > the > > flows induced by the vortex wake behind a lifting wing. Outboard of the > > wing a large upwash is induced, proportional to the circulation on the > > wing, and the wing man ("bird"?), if he tucks up tight on the tip, is > > flying in a strong upwash, with big drag savings. That's all there is to > > it! But, Ah, the Details! As Leonardo said "God is in the Details"! It > > would be boring to go into those mathematics, except to say that the > > procedure is considered well-understood and correct, but a helluva mess! > > The birdies jus' do it, and could care less! > > > > The first paper I know of that treated the topic mathematically (and > > brilliantly) was Wieselsberger in ZFM, 1914; and there has been a fairly > > lively activity since then, as computers have removed the formidable and > > intelligent math required, and made it possible for anyone to get results > > without understanding them. In 1969 Carl Shollenberger, my valued friend > > and colleague, and I worked on this, and published the results in Science. > > The paper (Lissaman & Shollenberger, Formation Flight of Birds, Science, > > Vol. 168, 1970) shows the very large size of these savings. We used the > > impressive new IBM 360 computer at Caltech. It occupied a three storey > > building about the size of a four unit apartment block, and had men's and > > women's toilets inside, as well as 12 real people who punched cards, fed > > data and generally dealt with the I/O. One picked up outputs at about > > 3:00 am each night. My wife never really believed that was what kept me > > up, although I did my thesis on mathematics of wing theory some years > > before using that old 360! And used the same story! Computation is > > clumsy, but more than Doktor Wieselsberger ever had! Carl was killed a > > few > > years later, flying in night mountain turbulence over the Sierra Madres. > > It was a great loss to aviation - he was a fine pilot and aerodynamicist. > > I acknowledge his contribution fondly. He would be glad that his work was > > still used. Recently I revisited this subject in a paper Simplified > > Analytical methods for Formation Flight (Lissaman, AIAA. Jan. 2005) and > > next week will give a paper Neutral Energy Cycles for a Vehicle in > > Sinusoidal and Turbulent Vertical Gusts (Lissaman & Patel, AIAA. Jan 2007) > > > > The Science paper shows that in theVee, for tight formations, one can > > almost double the range for a given energy input. Also that there is a > > stability mechanism, by which a member finds that moving ahead of the line > > of the Vee requires power increases. So there's a comfortable "groove" to > > fall into, which animals love! One should always be skeptical of > > attributing effects derived from theoretical calculations to animal > > behavior, but the general consensus of ornithologists and aerodynamicists > > is that this Vee formation saving is so significant, and its application > > so > > ubiquitous, that migrating birds DO use it to extend their range. The > > paper addressed the savings for different positions in the Vee. In line > > abreast, the center birds experience twice the saving of the tip members, > > but if the tip members find this hard work and fall back to take advantage > > of the increased favorable downstream upwash of the vortex wakes of the > > inner members, then a balancing of savings occurs. We calculated the angle > > of the Vee for equipartition. It is about the same as is observed with > > migrating birds. We also showed that it was not necessary have equal legs > > of the Vee. Provided there are at least about 6 birds on one side of the > > Vee, the other leg can be almost as long as the birds choose to make it. > > Interestingly, for a linear Vee, the wing at the apex of the Vee has the > > maximum saving. In 1971 I was in communication with ornithologists in > > Florida, who noted that their observations validated our Vee estimates and > > indicated that the apex position was usually taken by the older and more > > powerful birds. They wondered why the more powerful members of the flight > > should take the easiest jobs! My answer was that most intelligent species > > are pretty anthropomorphic! > > > > It may be noted that the savings are not related to drafting, that is > > following behind a draggy object to take advantage of its lower dynamic > > pressure wake. I am very familiar with this, and, as an automobile > > aerodynamicist, have utilized this theory in race car design, and as is > > obvious, the slingshot maneuver is very significant. But not in flight! > > It > > is, in fact, horrible to fly directly astern of another flight vehicle, as > > every pilot knows. Folks can, and do, get killed tangling with wake > > vortices, as I know to my sadness, when an old friend and experienced Navy > > pilot died as a consequence of following too close on final. > > > > Peter Lissaman, Da Vinci Ventures > > > > Expertise is not knowing everything, but knowing what to look for. > > > > 1454 Miracerros Loop South, Santa Fe, New Mexico 87505 > > TEL: (505) 983-7728 FAX: (505) 983-1694 > > > > > > > > > > > > > ---------------------------------------------------------------------------- ---- > > > > ============================================================ > > 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 mailing list > Friam@redfish.com > http://redfish.com/mailman/listinfo/friam_redfish.com > > > End of Friam Digest, Vol 43, Issue 9 > ************************************
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