@stigantonnielsen I'm curious what the power consumption of the rotor is in watts? I'm curious if it is in the range that could be produced by a cyclist ( up to ~300 watts). Also, would it be possible to estimate (in watts) the power imparted to the boat from the rotor, to give a sense of the ratio of power contributed to power gained from the wind?
Отличный проект с использованием эффекта Магнуса! По данным Флеттнера, скорость вращения ротора (линейная) должна быть выше в несколько раз скорости вымпельного ветра для достижения максимальной тяги. Ротор должен быть отполирован как можно лучше чтобы снизить требуемую мощность его привода. Удачи!
warum muss der Rotor poliert werden - es muss doch eine Grenzschicht aufgebaut werden, wenn der Rotor aalglatt ist, dürfte das doch eigentlich schwieriger sein? Ich habe mal gelesen, die dreifache Bahngeschwindigkeit zur Anströmung (=scheinbarer Wind) wäre optimal, deckt sich das mit Ihren Erfahrungen?
Your brief explanation in your comment is absolutely excellent! You did more to help subscribers understand what’s happening than this guy did with his voiceless video. Great job! Thanks for commenting!
I worked with a marine architect i for get his name but back in 1995?+/- hed had a small remote control trimaran with this rotating tube and it was actively "sailing" around the pond . Amazing to see these on ships now
Do you have plans to build a larger Catamaran with perhaps two or three rotating sails? Maybe even make them taller? I would imagine that would help with the overall speed. It would be cool to see more of this! And perhaps develop a mechanism that allows you to assemble and disassemble the mast and pivot it into position and have a simple yet strong lock mechanism.
It's un old system, by "Magnus Effect" named in french "turbo-voiles" .. already done in 80's by Jacques-Yves Cousteau and his son Jean-Michel Cousteau ..on a "big Catamaran" named ALCYONE !!! ..atypical system...and not very efficient... just a technical turpitude ... 😞
@@jacquesjuan6815 Alcyonne is a monohull, not catamaran. and she uses Turbo-sails not Magnus effect rotors. I've been a guest onboard her back in the 90s. Cousteau had designs for a trimaran with a flettner rotor, called calypso II but it was never built.
It would be helpful for observers if you could paint a shallow barber's pole helix on the rotor, to make it more obvious how fast and which direction the rotor is spinning.
Doubtful as the Coriolis effect does not come in to it. It is just the movement on the side of the rotor in the direction of the wind increases air velocity dropping pressure on that side producing thrust on the other side from atmospheric pressure. Probably the opposite effect on the side moving against wind direction. Footballers or snooker players do not have to adjust which side of the ball to hit imparting spin to curve it with the hemisphere. Look up the Magnus effect.
@@BrassLock I think you mean "swing bowling", which is a very fast delivery that deviates in the air due to aerodynamic action, like Wasim Akram did. Spin bowling (or seam bowling) is a slower ball which deviates after striking the ground, like Shane Warne did.
Beautiful project. I am curious how it would compare to a wing the same area as the rotor and if you could drive the rotor with a water turbine. Having the rotor be inflatable instead of rigid would allow easier reefing.
Litterature suggest that the area of a sail equivalent to a cylindrical rotorsail is the diameter of the rotor x 4. Yes, inflatable rotorsail is interesting since the shape of an inflatable naturally converges to round. Maybe you already saw my video with a model scale inflatable rotorsail and this indeed holds the potential to be reefed easily.
I built a model of a Magnus Effect windmill years ago in college. We only called it a model as there clearly was far too much friction to be effective in providing any drive. I’d like to see how this works in better winds.
I’m interested in your experience with the Magnus Effect where you built that model in college which experienced too much friction to provide any drive, as you mentioned. I’m considering building a similar scaled down model with my grandson, just as a science fair project, and I’d like to hear about the challenges you faced. Your input could be helpful to us in achieving positive results.
Cool proof of principle, but obviously impractical as a replacement for sail or screw prop. You would still get greater efficiency by applying the motor to turning a submerged propeller, and a sail offers greater utilisation of the available wind without the need for a motor. But as I said, cool proof. I've never seen this application of the Magnus effect before.
its a rotor sail. i work with trucking haulage from uk docks and i see a specific norwegian ship that uses the rotor spin as a fuel saver device and it works. but not as the main propulsion system. damn, thats hot. aerodynamics at its simpliest using rotation spheres. awesome 😊
It efficienter dan een propellor in water, want je stopt er energie in, en je krijgt er de wind energie bij. Er is waarschijnlijk een formule voor de efficientie
Great idea. Would your rotor sail work underwater to generate lift instead of a hydrofoil. Seems you could vary lift by changing speed quite easily, even lifting while boat is not moving forward
@@coffeyvideoproductions7767exactly my question! I am dabbling with making a small hydrofoil. It seems with a rotosail you could adjust the liftoff speed just by varying the rpm. This would allow a wide range of foiling speeds
Yes, we need much more tech info about what is going on. The motor appears to be tiny so that is obviously not what is driving the boat, just rotating the "wing".
We measured just once (7 km/h) when both (2x80kg) were onboard, so that was significantly slower than top speed. would guess 10-11 km/h was top speed. And regarding power usage the papers on the topic says about 15 % of total power is to drive the rotor, the other 85% is the wind - so well invested energy..
@@stigantonnielsen the trick is to use a wind turbine to get that 15% energy. maybe a Twisted Savonius Wind Turbine www.saltireserver.com/gx/vawt/PDFs/Board.pdf
There is not much centrifugal force since the radius amd mass of the verticle rotor is low. In the real world these devices tend to have problems with cracking at their base.
Actually it would be gyroscopics keeping it steady. This would also make the platform very stable as it can easily turn in the water as it moves around the axis of the cylinder but would be very difficult to tip it against the gyroscopic energy.
@@domenicozagari2443 It remains an issue which you have to deal with at proof of concept stage. It being that the overall concept is great, but scaling up, then being placed in real world environments where very strong gusts and waves can both alter the stresses between the axil and the base. How might these devices operate on a laterol axil instead of verticle?????
@@conormcmenemie5126 🤣 you really did not understood anything to the video and have no much clue either, the rotor is spinned by the motor, which is fed by a lithium battery. There is no propeller.
en.wikipedia.org/wiki/Flettner_rotor Heard about this in the 1970's. From "Look and Learn" Magazine. Back in the day when people used to learn about stuff.
Надо две трубы. Мешает смотреть вперед. Сетку для рыбы спереди тож забыли. Ещё лучше поставить снизу крылья. А две трубы под углом 60. Тогда вообще самолет будет.❤
Ahh ha,...are you available for questions ? I have a few,...#1, WTF,...#2. How does this design compare to using a prop,...as far as performance and energy consumption ? And # 3. WTF,...do you at anytime employ the powers of Voo Doo ? In this context, I am going to allow such query,..
Dont know what i'm seeing here Other than an electric motor pushing a small boat along with something spinning and charging the battery ? please explain what its doing
@ actually it is just the vertical cylinder with no prop in the water. See Ezra Richardson one 2yrs ago. He has better illustration etc. Again No prop in the water just the vertical cylinder Which seems so unexpected to generate thrust.
Good effort still not big or fast enough. I'm building a 3m x .3 dia rotor for 600 rpm, should produce about 5hp in 15 knots. I want it capable of more than a sunny day sail.
The rotation speed would need to be multiple times the windspeed to have the most effect, so a direct wind powered rotation is not so easy, requires at least some transmission and of course sufficent wind power in the first place. However, the problem is that in order to change direction for the boat (or when wind direction changes), the rotational direction also needs to be changes. That complicates things a bit mechanically if it was directly windpowered. So just having a battery that powers the motor is definitely a much easier solution.
The tube is spinning via an electric motor. Wind crossing the tube creates lift (forward thrust) much like a wing would. The advantage is it takes less energy to spin the tube than to propel the boat to that speed.
Roughly 6-7 times more energy is converted into boat thrust using a rotary sail than if you would just spend the same energy from the electric motor on a propeller in the water. (However the thrust from the rotor is not directly in the direction of the boat, as the propeller would be, so some is lost again. You could compare it to modern heat exchangers ( AC heater). With a heat exchanger you spend an amount of energy (1 unit) on extracting energy from an other energy source and capture around 2.5 -4 units. So yes, this is for sure more efficient - as long as the wind energy is there to convert.
My understanding is that when there is no wind, an initial impulse is required to get the boat moving. After that, the boat's movement can be enough to provide an effective air flow across the vertical rotor.
The Flettner rotor has been around fo donkey's years. As a young sailor I was aware of it in the early sixties... I'm dubious. If it's been present for such a long time without being used, what's wrong with it??? 🤔🤔🤔
It is in use as it can reduce fuel costs of ships if the wind is OK without having to have crew to handle sails. It is not widely used for similar reasons that sails are not widely used any more. You are on the clock and have deadlines.
Electric motor drives rotating cylinder. Wind interacts with rotating cylinder. Just as a ball is curving if it has sideways spin, the wind pushes the cylinder sideways, so it can propel the boat at an angle to the wind.
Le physicien italien Giovanni Battista Venturi (1746-1822) puis le physicien allemand Heinrich Gustav Magnus (1802-1870) ont tous deux étudié la mécanique des fluides et ont inspiré de très nombreuses applications. Fin XIX début XXe siècle une des applications a consisté à installer des cylindres tournants (d'abord 1 puis 3 alignés dans le sens de la longueur) sur des péniches naviguant sur la Seine. Grâce à ce procédé, les mâts tournants grâce à un moteur de faible puissance, entraînaient ces péniches grâce au vent et quelque soit sa direction et quelle que soit la direction de la péniche. Première contrainte, et pas des moindres : Les ponts sous lesquels il fallait passer et qui ont nécessité des bases articulées permettant d'affaler les cylindres... certains endroits comportant de très nombreux ponts était assez dissuasifs. La navigation en pleine mer est moins contraignante. Il faut tout de même avouer que le principe de la voile, en pleine mer, même s'il implique le tirage de bords, est beaucoup plus efficace. Quant aux péniches, tant que le pétrole est là, rien ne rivalise. Cela dit, étant donné l'immense surface libre sur les péniches, je ne comprends pas pourquoi on n'y installe pas une multitude de panneaux solaires qui fourniraient, il me semble, très largement la puissance demandée...Un important stock de batteries-tampon n'étant pas du tout rédhibitoire, en fond de cale, sur ce genre d'embarcation !
The interesting issue here is the difference in speed (= force) between using a certain amount of electric energy to run the rotor or use the same amount of energy to run a propeller?
Já vi um projeto assim. Parece que não pode ser posto em prática por aproveitar a energia dos carros que passam. Algo como direito autoral dos proprietários de veículos.
This is using what is referred to as the Magus effect. The cylinder is spinning and air that moves past it (wind) very near it's surface will be slowed down on one side (the side moving against the wind) and sped up on the other side (the side moving with the wind - if the surface of the cylinder is moving faster than the wind). Air that is moving faster is at a lower pressure than air with the same properties moving slower. This produces a net force on the cylinder. If you imagine the wind coming from the starboard (right side looking forward) and the cylinder turning counter clockwise, the net force will push the boat forward. If course, as the boat gains velocity, the apparent wind direction will change - you still have to know how to sail.
not very much. around 5 m/s I should think. It varied a bit across the lake as the boundary layer varied due to the landscape and trees around the lake.
The video where we are testing the first version of the rotor shows a little more explanation.. ruclips.net/video/JhAlWHSez90/видео.html But in short, the cylinder rotates, driven by a motor. The wind passing by the cylinder flows around say two sides of the cylinder. On one side of the cylinder the surface moves same direction as the wind causing the wind to pass faster, whereas the other side surface moves against the wind direction causing more friction and slower flow. The faster flow means lower pressure which in turn means lift on the cylinder. The principle is referred to as 'Flettner rotor' and 'Magnus effect' if you would like to search for more info.
It sure looked like the electric motor was spinning a jet ski pump under the mini catamaran.. Going downwind would work but the drag from the cross section of the cylinder going upwind or being hit by a sudden crosswind would be a N G..
I want to know what is in the center of the catamaran in the water is that some kind of a drive with a small propeller turning I keep zooming in and I can’t tell what it is that’s in the center of the catamaran??? Underwater..!! Look at time 5:51 It seems like there is some kind of thrust in between the sponson’s underwater. Looks like wake being pushed back. Look closely!!!! I might be wrong, but it looks like the wake of a propeller pushing forward this boat ?
just an aluminium dagger board plate - no other propulsion. clearly visible at around 4:00. Catamarans usually would have one daggerboard in eachof the hulls, but here because of a hard deck they opted for a center board counteracting the force of the rotor.
@@guidouytterhaegen This cylindrical sail utilizes something called "The Magnus effect" You can google it. The electric motors are to rotate the cylindrical "sail"
There’s a reason why they don’t flip the boat over and show you exactly what the drag board is doing. I have a catamaran and there is nothing in the water except for the two rudders. My kids like to swim under the middle of it
Imagine if you had access to stronger materials that are just as light as that foam! Imagine if you had it made out of carbon nanotubes or graphene carbon fiber! But that would be for larger ships, like container ships, oil tankers, and cruise ships
as much as I like the idea of using wind and Magnus effect and Flettner rotor, the biggest problem is that you have to remove the rotor while sitting in a port or at anchor, otherwise you will encounter the fate of the 'Bayesian'. You have a sail area of about 1m² with 3m in height I think, and a quite small beam... How will this system be able to cope with higher wind loads and higher rotors?
One solution for solid cylinders is to have them mounted on a hinge, so they can be laid flat in port or when passing under bridges. So there are solutions to "the biggest problem". Then something else becomes the biggest problem.
The max possible for the motor at this setup is 1000 RPM which is fast for this large a body.. but a rotor sail achieves good results at surface speed 3 times the wind passing the rotor. At a wind speed of 7 m/s and a circumference of 0,91m it is 23 rounds/sec which is 1380 rpm..so maybe not quite fast enough for the gusts that day..
@@stigantonnielsen There is an advantage of the decrease when a gust occurs. Points on the drag coefficient curve 0.0 1.2 ratio 1.2 at 1 ratio lowest 0.7 4 ratio 2.5 goes flat at about 5 around 3.5 this is for a Reynolds number 16000 for all the data and 32000 for the first three ratios at the higher Reynolds. the spinning cylinder lift coefficient about a 4 ratio at about 8.5 and for the higher RE ratio of 5 at a coef of 11. A sail will continue to create lift if it is not stalled which it would be for a gust as a ratio of the square of the velocity. Same square applies to the cylinder but the ratio decrease which lowers the coefficient as the square increases.
Gente, não me convenceu. Num lugar bom de vento, uma boa escolha de velas faz o barco se deslocar já na areia. Precisaria ver mais de perto e conferir o controle de rotação.
De hecho se aprovecha el viento, y hay bastantes estudios sobre el tema, puedes buscarlo como efecto Flettner, para darte un ejemplo es lo que da la curvatura a una pelota en un tiro libre, la.ventaja de esto es la economía que produce para mover una embarcación, menos energía, ya se están usando en algunos barcos, para economizar combustible
ruclips.net/video/XsGin7CFaF8/видео.htmlsi=Qd_KwnZcDkVTgTaD. This will explain, yes the vertical column needs to spin, that is done electrically. With it spinning, the wind across will create negative pressure or lift. So while this looks ridiculous, it does work.
I don't get it. I was expecting them to add blades to it and transmit the motion of the spinning column and gear it to a propeller. Then sail in any wind, in any direction they wish and completely do away with the age old tac.
This video needs a commentary and an explanation of the flettner rotor principle.
Лобановский, забивая в ворота мяч, с углового положения, всё объяснил на практике (и для специалистов формулами)..
magnus effect
.. drone too 😂
It's earned a solid 👎👎
Really, I don't get it. I was expecting them to add blades to it and direct the spinner to a propeller.
exceptional application of the physical laws.. great guys...
I built a model catamaran with the same rotating drum sail about 60 years ago and tested it in our pool. The theory worked.
Fascinating. First time I've seen this in action.
There are actually some larger ships which have these mounted. It's called a Flettner rotor.
@@astorMorisson AN OLD SCUBA DIVER HERE. DIDN'T J. COSTEAU HAVE A TRI-MARAN WITH THIS? WHAT WAS ITS RESULTS?
@stigantonnielsen I'm curious what the power consumption of the rotor is in watts? I'm curious if it is in the range that could be produced by a cyclist ( up to ~300 watts). Also, would it be possible to estimate (in watts) the power imparted to the boat from the rotor, to give a sense of the ratio of power contributed to power gained from the wind?
You can probably easily drive it with pedals.
Отличный проект с использованием эффекта Магнуса! По данным Флеттнера, скорость вращения ротора (линейная) должна быть выше в несколько раз скорости вымпельного ветра для достижения максимальной тяги.
Ротор должен быть отполирован как можно лучше чтобы снизить требуемую мощность его привода.
Удачи!
warum muss der Rotor poliert werden - es muss doch eine Grenzschicht aufgebaut werden, wenn der Rotor aalglatt ist, dürfte das doch eigentlich schwieriger sein? Ich habe mal gelesen, die dreifache Bahngeschwindigkeit zur Anströmung (=scheinbarer Wind) wäre optimal, deckt sich das mit Ihren Erfahrungen?
Your brief explanation in your comment is absolutely excellent! You did more to help subscribers understand what’s happening than this guy did with his voiceless video. Great job! Thanks for commenting!
God anvendelse af valgplakater!
Og spændende projekt :-)
Ja valgplakater er fint materiale til mange projekter:) kan ikke lige se hvilken kandidat der fik æren som tip-loss-preventer hahah
I worked with a marine architect i for get his name but back in 1995?+/- hed had a small remote control trimaran with this rotating tube and it was actively "sailing" around the pond . Amazing to see these on ships now
Would like to see a comparison with similar sized traditional sail boat ⛵️
Do you have plans to build a larger Catamaran with perhaps two or three rotating sails? Maybe even make them taller? I would imagine that would help with the overall speed. It would be cool to see more of this!
And perhaps develop a mechanism that allows you to assemble and disassemble the mast and pivot it into position and have a simple yet strong lock mechanism.
It's un old system, by "Magnus Effect" named in french "turbo-voiles" .. already done in 80's by Jacques-Yves Cousteau and his son Jean-Michel Cousteau ..on a "big Catamaran" named ALCYONE !!!
..atypical system...and not very efficient... just a technical turpitude ... 😞
@@jacquesjuan6815 Alcyonne is a monohull, not catamaran. and she uses Turbo-sails not Magnus effect rotors. I've been a guest onboard her back in the 90s. Cousteau had designs for a trimaran with a flettner rotor, called calypso II but it was never built.
How does it work?
It would be helpful for observers if you could paint a shallow barber's pole helix on the rotor, to make it more obvious how fast and which direction the rotor is spinning.
Simply beautiful! Kudos!
thank you for sharing your work and educating those people who are interested in humans helping humans.
How close to the wind can you sailed does the wind effect it.
Awesome, now lets get some foils on that!
does the direction of rotation have effect on hemisphere of operation?
Doubtful as the Coriolis effect does not come in to it. It is just the movement on the side of the rotor in the direction of the wind increases air velocity dropping pressure on that side producing thrust on the other side from atmospheric pressure. Probably the opposite effect on the side moving against wind direction. Footballers or snooker players do not have to adjust which side of the ball to hit imparting spin to curve it with the hemisphere. Look up the Magnus effect.
Is this the *_"spin bowler effect"_* as used by Richie Benaud, Shane Warne, and many other cricketers?
@@BrassLock I think you mean "swing bowling", which is a very fast delivery that deviates in the air due to aerodynamic action, like Wasim Akram did.
Spin bowling (or seam bowling) is a slower ball which deviates after striking the ground, like Shane Warne did.
Beautiful project. I am curious how it would compare to a wing the same area as the rotor and if you could drive the rotor with a water turbine. Having the rotor be inflatable instead of rigid would allow easier reefing.
Litterature suggest that the area of a sail equivalent to a cylindrical rotorsail is the diameter of the rotor x 4. Yes, inflatable rotorsail is interesting since the shape of an inflatable naturally converges to round. Maybe you already saw my video with a model scale inflatable rotorsail and this indeed holds the potential to be reefed easily.
One of the reasons rotor sails is not more adopted is the limited lift to drag. Sails can achieve much higher L/D coefficients.
What is the part that is submerged in the water in the middle of this boat?
I built a model of a Magnus Effect windmill years ago in college. We only called it a model as there clearly was far too much friction to be effective in providing any drive.
I’d like to see how this works in better winds.
I’m interested in your experience with the Magnus Effect where you built that model in college which experienced too much friction to provide any drive, as you mentioned. I’m considering building a similar scaled down model with my grandson, just as a science fair project, and I’d like to hear about the challenges you faced. Your input could be helpful to us in achieving positive results.
Cool proof of principle, but obviously impractical as a replacement for sail or screw prop.
You would still get greater efficiency by applying the motor to turning a submerged propeller, and a sail offers greater utilisation of the available wind without the need for a motor.
But as I said, cool proof. I've never seen this application of the Magnus effect before.
I've heard of this but first time I ever saw it actually worked nobell prize maybe
No fucking way ! So at 45 years old there were still things I never heard of !
Same story😂
Topolobampo! Kriga kriga tarmangani, paranguaricuturimicuaro! 😮😮😊
its a rotor sail. i work with trucking haulage from uk docks and i see a specific norwegian ship that uses the rotor spin as a fuel saver device and it works. but not as the main propulsion system. damn, thats hot. aerodynamics at its simpliest using rotation spheres. awesome 😊
IMBÉCILE
It works really fine. Its a Styropor wonder😊
Tiz eletric powerd how does batery last
Lol
nice vid m8, and not a lot of talk about how it works love it most YT the talk to much and nothing happens really good just looking at the thingy 🙂
Интересно узнать какая энергия затрачивается на вращение этого паруса и не проще ли напрямую вращать винт в воде?
It efficienter dan een propellor in water, want je stopt er energie in, en je krijgt er de wind energie bij.
Er is waarschijnlijk een formule voor de efficientie
Neat idea. Suggestion for your video sound; get a wind protector
So the cylinder doesn't have to rotate to push the boat?
Great idea. Would your rotor sail work underwater to generate lift instead of a hydrofoil. Seems you could vary lift by changing speed quite easily, even lifting while boat is not moving forward
Funny finding your question here. I came looking for rotosails to ask what effect the sail could have underwater.
@@coffeyvideoproductions7767exactly my question! I am dabbling with making a small hydrofoil. It seems with a rotosail you could adjust the liftoff speed just by varying the rpm. This would allow a wide range of foiling speeds
I assume a rougher surface is desirable not a smooth surface would contouring assist moving the air?
In the 1960's someone put those on a cargo ship for trans-Atlantic shipping with some success but apparently not commercially viable.
Yes it would be nice to hear anything at all about anything at all.
Yes, we need much more tech info about what is going on. The motor appears to be tiny so that is obviously not what is driving the boat, just rotating the "wing".
Wow, very impressive build! :D Do you have an approximation of the speed and the power used?
We measured just once (7 km/h) when both (2x80kg) were onboard, so that was significantly slower than top speed. would guess 10-11 km/h was top speed. And regarding power usage the papers on the topic says about 15 % of total power is to drive the rotor, the other 85% is the wind - so well invested energy..
@@stigantonnielsen the trick is to use a wind turbine to get that 15% energy. maybe a Twisted Savonius Wind Turbine www.saltireserver.com/gx/vawt/PDFs/Board.pdf
Centrifugal force keeps it steady.
There is not much centrifugal force since the radius amd mass of the verticle rotor is low. In the real world these devices tend to have problems with cracking at their base.
@@conormcmenemie51264 stays should support the center pole from moving and cracking the base.
Actually it would be gyroscopics keeping it steady. This would also make the platform very stable as it can easily turn in the water as it moves around the axis of the cylinder but would be very difficult to tip it against the gyroscopic energy.
@@conormcmenemie5126 My design would be a vertical rectangular cube turbine with 4 sides, each side half closed to stop the negative wind.
@@domenicozagari2443 It remains an issue which you have to deal with at proof of concept stage. It being that the overall concept is great, but scaling up, then being placed in real world environments where very strong gusts and waves can both alter the stresses between the axil and the base. How might these devices operate on a laterol axil instead of verticle?????
Jacques Cousto had a ship with 2 rotosails Allypso ? any way it crossed the Atlantic 12 times.
Great :) Can you tell what the outer shell of the cylinder is made of ?
It looks like thin Styrofoam sheets ~ 3mm thick rolled around Styrofoam disks to make cylinders not too heavy, epoxy taped at the seams?
Fly paper.
Half inch steel plate.
Oh thank god youbjust made my day 😂🎉🎉🎉🎉🎉@@robertkustos2931
Not sure what I just saw...looked interesting though. Long time multi sailor here. Where was this?
There's quite a few comments explaining how it works.
How is the size of the cylinder determined to move what boat size? Which matters more, the diameter or height?
Diameter height and rotational speed all influence the thrust.
Recently there was someone that made 2 horizontal cylinders in a frame, front and back and it flew.
I må beskrive hvorfor, den roterende søjle skulle være mere effektiv en at bruge samme effekt på en propel eller andet direkte i vandet.?
What ? Is electricity spinning the rotor or the wind ? ?
The wind spins the verticle rotor which powers the propeller.
@@conormcmenemie5126 🤣 you really did not understood anything to the video and have no much clue either, the rotor is spinned by the motor, which is fed by a lithium battery. There is no propeller.
@@lo2740 You are perhaps cultured but certainly not a kind person.🤢
en.wikipedia.org/wiki/Flettner_rotor
Heard about this in the 1970's. From "Look and Learn" Magazine. Back in the day when people used to learn about stuff.
@@tonypowell1167 Massive thanks dude - I had got it into my head from back in the 70s that they were generators - my bad
Can it sail directly against the wind?
When they tack/ gybe does the rotor stay the same or needs to reverse?
Pretty sure it needs to reverse
@@goglinasgolosinas64 Yes, reverse. The rotor has quite some mass and builds up some inertia.
A Flettner rotor ,cool.😊
I would like this to have been explained as I don't understand the concept
Just Google Magnus effect or Flettner rotors
Experiments with roto-sails, but with multiples, were conducted in the 1920s-1930s on smaller full-sized ships.
Надо две трубы. Мешает смотреть вперед. Сетку для рыбы спереди тож забыли. Ещё лучше поставить снизу крылья. А две трубы под углом 60. Тогда вообще самолет будет.❤
I got an idea.....ditch the 10' tall rotor and connect the pwr to a makita trolling motor, you'll get there quicker
Очень интересный фильм! Спасибо.
Is it just me that wants to re-paint that rotor in some candy shop style?
HAHA, Yeah we should have painted some pattern to show the rotation clearly! Next time...
Barber shop like
Barber pole,...
Ahh ha,...are you available for questions ? I have a few,...#1, WTF,...#2. How does this design compare to using a prop,...as far as performance and energy consumption ? And # 3. WTF,...do you at anytime employ the powers of Voo Doo ? In this context, I am going to allow such query,..
Barber pole it.
Dont know what i'm seeing here Other than an electric motor pushing a small boat along with something spinning and charging the battery ? please explain what its doing
Is using a Flettner Rotor ...see en.wikipedia.org/wiki/Flettner_rotor
Not pushing but the spinning white bit is generating forward thrust fyi.
@@LWJCarroll ok ! but that alone is not moving the boat ! it helps it But still needs the electric trust in the water for initiate movement
@ actually it is just the vertical cylinder with no prop in the water. See Ezra Richardson one 2yrs ago. He has better illustration etc. Again No prop in the water just the vertical cylinder Which seems so unexpected to generate thrust.
@ thanks I didnt see that.
would it work if you have the propeller in the water directly rotating the sail?
Like a reversed propeller, with drag.
How would the boat be able to start?
Good effort still not big or fast enough.
I'm building a 3m x .3 dia rotor for 600 rpm, should produce about 5hp in 15 knots.
I want it capable of more than a sunny day sail.
How does it work??
There's plenty of explanations in the comments. Interesting reads.
There is more energy in than out. Doesn't look like it's using any wind energy-assisted lift.
That looks great. Would it be possible for the rotor to be wind-driven, or would the rotational speed be too low to be useful ?
The rotation speed would need to be multiple times the windspeed to have the most effect, so a direct wind powered rotation is not so easy, requires at least some transmission and of course sufficent wind power in the first place. However, the problem is that in order to change direction for the boat (or when wind direction changes), the rotational direction also needs to be changes. That complicates things a bit mechanically if it was directly windpowered. So just having a battery that powers the motor is definitely a much easier solution.
С гребным винтом быстрее
Didn't Cousteau have a ship w/ rotor sail?🤔
Yes he did ..I think he adapted it to the calypso
@@gregdowd939not a great succes
@@erich3507 Someone above said he crossed the Atlantic ocean with it 12 times!
😂find the so called someone... @@williadYT
Es de tergopol?
Magnus-effekten.
Imponerende bra!
why is there only a tipp loss rotor at the top? it has no tipp loss at the bottom?!
I guess the boat it self serves that function?
sure sounds battery driven....?
The tube is spinning via an electric motor. Wind crossing the tube creates lift (forward thrust) much like a wing would. The advantage is it takes less energy to spin the tube than to propel the boat to that speed.
interesting. what about efficiency? is it more efficient than putting this electric power to underwater propeller?
Thats the million dollar question
Good question.
Roughly 6-7 times more energy is converted into boat thrust using a rotary sail than if you would just spend the same energy from the electric motor on a propeller in the water. (However the thrust from the rotor is not directly in the direction of the boat, as the propeller would be, so some is lost again. You could compare it to modern heat exchangers ( AC heater). With a heat exchanger you spend an amount of energy (1 unit) on extracting energy from an other energy source and capture around 2.5 -4 units. So yes, this is for sure more efficient - as long as the wind energy is there to convert.
@stigantonnielsen It doesn't use WIND energy. No way it's ten times more effective than a propeller. Where is your equation?
@@stigantonnielsen "heat exchanger" = heat pump...?
That's amazing! Personally, I sail to get away from the sound of motors.
Which does raise the question..could a vawt turn the magnus mast?
Will this work if there is no wind?
My understanding is that when there is no wind, an initial impulse is required to get the boat moving. After that, the boat's movement can be enough to provide an effective air flow across the vertical rotor.
Effectiveness?
This cannot be as efficient as a set of sails.
I would be curious to see a race between a boat in original sail configuration and the roter sail.
And maybe if speed was the only consideration that would be valid.
The Flettner rotor has been around fo donkey's years. As a young sailor I was aware of it in the early sixties... I'm dubious. If it's been present for such a long time without being used, what's wrong with it??? 🤔🤔🤔
It is in use as it can reduce fuel costs of ships if the wind is OK without having to have crew to handle sails. It is not widely used for similar reasons that sails are not widely used any more. You are on the clock and have deadlines.
What drives what?
Electric motor drives rotating cylinder. Wind interacts with rotating cylinder. Just as a ball is curving if it has sideways spin, the wind pushes the cylinder sideways, so it can propel the boat at an angle to the wind.
I always thought sails used wind power. This one is electric. Maybe a trolling motor would be save space and be simpler.
Mimicking the Cousteau vessel?
How does this work
Magnus effect 🤗
Le physicien italien Giovanni Battista Venturi (1746-1822) puis le physicien allemand Heinrich Gustav Magnus (1802-1870) ont tous deux étudié la mécanique des fluides et ont inspiré de très nombreuses applications. Fin XIX début XXe siècle une des applications a consisté à installer des cylindres tournants (d'abord 1 puis 3 alignés dans le sens de la longueur) sur des péniches naviguant sur la Seine. Grâce à ce procédé, les mâts tournants grâce à un moteur de faible puissance, entraînaient ces péniches grâce au vent et quelque soit sa direction et quelle que soit la direction de la péniche.
Première contrainte, et pas des moindres : Les ponts sous lesquels il fallait passer et qui ont nécessité des bases articulées permettant d'affaler les cylindres... certains endroits comportant de très nombreux ponts était assez dissuasifs.
La navigation en pleine mer est moins contraignante.
Il faut tout de même avouer que le principe de la voile, en pleine mer, même s'il implique le tirage de bords, est beaucoup plus efficace.
Quant aux péniches, tant que le pétrole est là, rien ne rivalise.
Cela dit, étant donné l'immense surface libre sur les péniches, je ne comprends pas pourquoi on n'y installe pas une multitude de panneaux solaires qui fourniraient, il me semble, très largement la puissance demandée...Un important stock de batteries-tampon n'étant pas du tout rédhibitoire, en fond de cale, sur ce genre d'embarcation !
The interesting issue here is the difference in speed (= force) between using a certain amount of electric energy to run the rotor or use the same amount of energy to run a propeller?
It is not also able to make electricity?
Thousands along highways etc .
Even birds getting not smashed. ..
Já vi um projeto assim. Parece que não pode ser posto em prática por aproveitar a energia dos carros que passam. Algo como direito autoral dos proprietários de veículos.
I'm building a similar project, can you help out with the dimensions and materials used. Thanks
The cylinder is probably styrofoam sheets bent to make a tube. There's 5 mill sheets in our hardware store.
Please explain how this works.
This is using what is referred to as the Magus effect. The cylinder is spinning and air that moves past it (wind) very near it's surface will be slowed down on one side (the side moving against the wind) and sped up on the other side (the side moving with the wind - if the surface of the cylinder is moving faster than the wind). Air that is moving faster is at a lower pressure than air with the same properties moving slower. This produces a net force on the cylinder. If you imagine the wind coming from the starboard (right side looking forward) and the cylinder turning counter clockwise, the net force will push the boat forward. If course, as the boat gains velocity, the apparent wind direction will change - you still have to know how to sail.
Think like doing a back spin on a tennis ball.
uncredible- works very strong ! How was the windspeed in m/s?
not very much. around 5 m/s I should think. It varied a bit across the lake as the boundary layer varied due to the landscape and trees around the lake.
Would someone please explain what's going on here ???
The video where we are testing the first version of the rotor shows a little more explanation.. ruclips.net/video/JhAlWHSez90/видео.html
But in short, the cylinder rotates, driven by a motor. The wind passing by the cylinder flows around say two sides of the cylinder. On one side of the cylinder the surface moves same direction as the wind causing the wind to pass faster, whereas the other side surface moves against the wind direction causing more friction and slower flow. The faster flow means lower pressure which in turn means lift on the cylinder. The principle is referred to as 'Flettner rotor' and 'Magnus effect' if you would like to search for more info.
en.m.wikipedia.org/wiki/Flettner_rotor#:~:text=A%20Flettner%20rotor%20is%20a,and%20the%20direction%20of%20airflow.
@@stigantonnielsen not lift on the cylinder but forward pull
@@stigantonnielsen DEEPLY APPRECIATED AND BITD JACQUES COSTEAU HAD AN (?) TRANS OCEANIC ??
I honestly cannot grasp how this works
And maybe some video from the shore?
No explanation of any kind? Nice.
It sure looked like the electric motor was spinning a jet ski pump under the mini catamaran.. Going downwind would work but the drag from the cross section of the cylinder going upwind or being hit by a sudden crosswind would be a N G..
superb,lovely to see.
I want to know what is in the center of the catamaran in the water is that some kind of a drive with a small propeller turning I keep zooming in and I can’t tell what it is that’s in the center of the catamaran??? Underwater..!! Look at time 5:51 It seems like there is some kind of thrust in between the sponson’s underwater. Looks like wake being pushed back. Look closely!!!! I might be wrong, but it looks like the wake of a propeller pushing forward this boat ?
just an aluminium dagger board plate - no other propulsion. clearly visible at around 4:00. Catamarans usually would have one daggerboard in eachof the hulls, but here because of a hard deck they opted for a center board counteracting the force of the rotor.
@@peter2uatif the boat is propelled only with the rotor…then why all that electric around it😊😂😂
@@guidouytterhaegen This cylindrical sail utilizes something called
"The Magnus effect" You can google it. The electric motors are to rotate the cylindrical "sail"
just to turn the rotor!
There’s a reason why they don’t flip the boat over and show you exactly what the drag board is doing. I have a catamaran and there is nothing in the water except for the two rudders. My kids like to swim under the middle of it
Imagine if you had access to stronger materials that are just as light as that foam!
Imagine if you had it made out of carbon nanotubes or graphene carbon fiber!
But that would be for larger ships, like container ships, oil tankers, and cruise ships
FREAKING AWESOME
👍 Faut rajouter des foils !!!! 😉
as much as I like the idea of using wind and Magnus effect and Flettner rotor, the biggest problem is that you have to remove the rotor while sitting in a port or at anchor, otherwise you will encounter the fate of the 'Bayesian'. You have a sail area of about 1m² with 3m in height I think, and a quite small beam... How will this system be able to cope with higher wind loads and higher rotors?
Other flettners I've seen use a fabric tube that was being developed to be able to control surface area.
One solution for solid cylinders is to have them mounted on a hinge, so they can be laid flat in port or when passing under bridges. So there are solutions to "the biggest problem". Then something else becomes the biggest problem.
При создании следующего видео, укажите на экране скорость ветра, скорость катамарана, частоту вращения и потребляемую мощность привода ротора.
The motor hum is off putting but it is real cool tech.
Quite interesting.....if we knew WTF we were watching..or perhaps how this contraption works....🤔
A film is due out soon.
Around the world in 180 years.
Google Magnus rotor.
How fast does it have to spin?
The max possible for the motor at this setup is 1000 RPM which is fast for this large a body.. but a rotor sail achieves good results at surface speed 3 times the wind passing the rotor. At a wind speed of 7 m/s and a circumference of 0,91m it is 23 rounds/sec which is 1380 rpm..so maybe not quite fast enough for the gusts that day..
@@stigantonnielsen There is an advantage of the decrease when a gust occurs. Points on the drag coefficient curve 0.0 1.2 ratio 1.2 at 1 ratio lowest 0.7 4 ratio 2.5 goes flat at about 5 around 3.5 this is for a Reynolds number 16000 for all the data and 32000 for the first three ratios at the higher Reynolds. the spinning cylinder lift coefficient about a 4 ratio at about 8.5 and for the higher RE ratio of 5 at a coef of 11. A sail will continue to create lift if it is not stalled which it would be for a gust as a ratio of the square of the velocity. Same square applies to the cylinder but the ratio decrease which lowers the coefficient as the square increases.
What about adding some foils to reduce consumption.
Gente, não me convenceu.
Num lugar bom de vento, uma boa escolha de velas faz o barco se deslocar já na areia.
Precisaria ver mais de perto e conferir o controle de rotação.
Great project!
That's one sexy sailboat
Se não aproveita o vento, qual a vantagem sobre um motor convencional? Não entendi. É só estudo acadêmico?
De hecho se aprovecha el viento, y hay bastantes estudios sobre el tema, puedes buscarlo como efecto Flettner, para darte un ejemplo es lo que da la curvatura a una pelota en un tiro libre, la.ventaja de esto es la economía que produce para mover una embarcación, menos energía, ya se están usando en algunos barcos, para economizar combustible
@@ElViejoNerd obrigado pela atenção!
ruclips.net/video/XsGin7CFaF8/видео.htmlsi=Qd_KwnZcDkVTgTaD. This will explain, yes the vertical column needs to spin, that is done electrically. With it spinning, the wind across will create negative pressure or lift. So while this looks ridiculous, it does work.
No dock lines or fenders. Is this in Florida? 😂
I don't get it. I was expecting them to add blades to it and transmit the motion of the spinning column and gear it to a propeller. Then sail in any wind, in any direction they wish and completely do away with the age old tac.
That is not it. But maybe you can build one like that and put it on youtube?