Flettner Rotor Sail Cart // Homemade Science with Bruce Yeany
Vložit
- čas přidán 26. 07. 2024
- The Flettner rotor is a large spinning cylinder that was originally developed to harness wind energy for moving large transport ships. It was introduced during the 1920's and uses the Magnus Effect to capture the wind instead of a more traditional sail found on older boats. In this video a small cart has a large spinning rotor attached is used to demonstrate how the Magnus Effect and the Coandă effect are the result of Bernoulli's principle.
I love how you "complete the thought" with your videos and go that extra step to show variations and answer the "why we're seeing what we're seeing" question
Thank you for all that you do, I can't wait to for my son to be born and show him all the things that are amazing in this world that we gloss over in our daily lives!
People keep talking about laurel? Is this him? Idk
Absolutely excellent demonstration! Thank you
What a great demonstration of this effect! A passenger ship around here has a big rotor like this on the deck, it has always facinated me.
Thanks for the amazing things you show us on your channel.
lazar gamezz People keep talking about laurel? Is this him? Idk
CJ Lilac why are you doing this? I know you are referring to yanny/laurel, but why?
Marvelous demonstrations! Thank you for showing us alternate shapes and a stationary rotor!
By favorite science teacher is back 😀
People keep talking about laurel? Is this him? Idk
CJ Lilac yes
Anyone notice the handle on his microwave?
Please don't ever stop making videos. You are amazing!
Thank you for an exceedingly interesting, educational and fun demonstration of the science behind this phenomenon. You explained it very well.
I havent seen one of your videos in a while. It made me so happy to see you still posting
I so enjoy your presentations thank you Bruce. love and laughter.
Bruce is back!!
that's right, im back....
Bruce Yeany, thank you very much. Through your videos, I see one of the ways to change science education in Brazil.
Bruce, outstanding as always. Thank you!
your welcome
It's always a pleasure to watch your content. Thank you.
Yes, a two-fer! 👍 Great stuff Bruce!
Fun science is so fun. Thank you for the great demonstration!
People keep talking about laurel? Is this him? Idk
Great demonstrations! I always learn something new
Great work Bruce, love your video's! Keep up the good work!
Guus Remijn People keep talking about laurel? Is this him? Idk
Thanks!
Great demo.
Excelente profesor . Sus videos nos ayudan a mejorar nuestras clases
i am so off on a tangent now, thank you for this video. i shared a link to it on facebook. then i was wondering about sniper bullets and the magnus effect, and sure enough, someone made a fascinating video about it - ok back to work!! why does youtube have to be so interesting all the time?!?
THANK YOU for the great educational content! (and for going through the trouble of spelling Coandă correctly :) )
Great video. Thank you.
Ver tu canal, es un descubrimiento, buen trabajo.
Amazing video and explanation. Thank you very much
Great video Thanks
thanks for great demo, will show to my daughter
Super! I totally approve such approach) Science is everywhere
great video
Thanks really enjoy your work
You r great
U always give me creative idea
Thanks alots..
that was AWESOME!
thanks for making this video, helps a lot!!
Great Video!!!
I love your content! Keep it up!
very cool effect!
Wish i had a science teacher like you
That's pretty amazing
I wish mr.bruce were my science teacher. Great respect from Japan.
He was my science teacher!
Thanku very much sir for explaining the principle with some real life demonstrations. I am a new member to your community and I will be following you as long as possible. With lots of love from a student❤❤
Thank you sir you explained in a very simple and practical way, easy to understand the concept :)
ótimo vídeo!
Love this!
Muchas gracias.
Awesome !
very nice!
Thank you!
Thanks for video :)
Better than my aerodynamics professor.
I built an RC sailboat using one of these. It worked pretty well! I just used a PVC tube directly on the top of a brushless out runner electric motor Lol! I could get about 40minutes to an hour of run time of run time. So overall pretty successful!
to me it seems that if he had put the little electric motor turning the wheels the car would have made headway against the vacuume cleaner's exhaust if he had blasted the little cart head on. after all these long years of trying to push this concept, lets just put it to bed. may as well put oars on the ship and let the refugees of various conflicts world wide man the oars.
@@johngillon6969 That's not the point. Besides: It takes more energy to drive wheels on a vehicle or a propeller in water then to spin a tube. It's a sail, not conventional propulsion. You have to tack and stuff to go into the wind!
@@ezrarichardson279 The point is if all the energy from those batteries was applied to the wheels it would be faster no matter what. the energy to spin the rotor would be more efficiently used by driving the wheels or a propeller. i feel like i am discussing efficiency with someone who would argue in favor of a recumbent bicycle over the traditional racing bike. i just think over one hundred years of beating a dead horse is kind of a waste of time. if the rotor were a profitable venture, there would have been more of them floating around. this is of course an interesting phenomena. and if recumbant bicycles were more efficient, than you would see them competing in the tour de france. BTW do you enjoy reding science fiction.? my self prefers Louis Laamore, i guess it may be a divide between a traditionalist and those prefer to constantly re invent the wheel. Why?
@@johngillon6969 The question isn't about speed, but efficiency. And besides, the speed of the vehicle is proportional to the wind velocity so it could absolutely be faster than the same motor attached to the wheels directly. Also, recumbent bicycles are among the fastest and most efficient bikes out there (although I prefer traditional ones personaly). My point is that if you're using a couple amps for a long period of time to spin a tube which is supplementing and helping along a traditional propulsion system, that propulsion system will be more efficient and faster overall. After all, it's not the tube that creating the force, it's the wind. And to be fair, the whole point of this video is to show case a cool science concept, it has nothing to do with proving viability. None of this stuff scales particularly well either.
Intriguing
Ufkun bizi geliştiriyor teşekkürler
Hey Bruce it's me from your last video! I really love your channel and I think it's really great that your still doing this even though you are no long a school teacher. On my channel I actually dedicated one of my videos to you, in the video I study for my science quiz and go through some science topics. Can wait for the next upload!!😀
I remember. It looks like you've been busy with your channel, kept at it, find the things that you're interested in and keep posting and you'll keep growing on youtube.
Thanks so much! I'll definitely make sure to do that!
Great!
Wow, you are _good_.
I read recently that a bulk carrier shipping company is building a ship with Flettner rotors to carry 10s of thousands of tons wood pellets. Now I understand why.
Coanda foreva!
you are awesome
Dudes hand in volly ball shot looks alien or broken...
Also, cool science bro. I like it
I'm glad the screen waited til the end to black out.
I can not imagine that the rotor can be as effective as an oldfashioned fabric sail. have never seen any one compare the two. Personally i think the rotor is a waste of time. but i got time so thanks for the video dude.
I think why you don’t see sails on cargo ships is because
1) you would need to double the number of crew to man the sails
2) if a rotor gets in the way of loading, imagine several masts
3) how big would the masts need to be to propel even a PanaMax cargo ship and how could you control it in port?
Rotors for airplane wings-
"This idea never took off".
Bah-dah-bum,-tiss!
Q: in the the static rotor experiment what will happen if an obstacle introduced ?
Hi Bruce - Great experiment. I never knew about this kind of rotor before.
A few questions, that I hope you can address, perhaps in a new video:
1. Is it always required for the wind direction to be perpendicular to the rotor? Can the wind vector be at any angle and still generate the same amount of forward motion power?
2. What happens if the wind is exactly behind or ahead of the craft? If it is akin to a sailboat, can the craft move directly upstream or downstream relative to the wind flow?
3. Finally, wouldn't a rotor with fins or blades be more efficient to spin the rotor?
My thoughts exactly! I will refer to this diagram iveybusinessreview.ca/wp-content/uploads/2018/04/Hapag-Lloyd-Graphic-2-Rotor-Magnus-Effect.png
If the wind is coming perpendicular from the left (the port side), and the Flettner rotor is spinning clockwise when viewed from above, the thrust will move the ship forward. Yay! All is right in the world!
If the wind is coming perpendicular from the right (the starboard side), and the Flettner rotor’s mechanized spin is REVERSED to be counter-clockwise, the thrust will move the ship forward. Yay! All is right in the world!
But it seems that if it’s coming from any other angle, the thrust would continue to add to the ship’s forward motion, BUT IT WOULD ALSO PUSH THE SHIP OFF COURSE. So, if you are traveling from China to Los Angeles, you could end up in Mexico or Canada (if you don’t compensate by steering). This is similar to flying an airplane. You can point the plane in the direction of Washington DC, but you need to compensate for the lateral forces of the winds aloft.
So my QUESTION is, can the Flettner rotor’s thrust be directed beyond reversing the Flettner’s motor (or shutting it off)?
By the way, if you WANTED to go backwards (to stern) or sideways, I suppose the Flettner could be used under favorable conditions. But I don’t see that as useful except to avoid collisions or in port, and in port I would think the thrust would not be precise enough.
One other thought. It would seem to me that the Flettner rotor would at least increase drag if the ship is not perpendicular to the wind. Then again, winds push ships off course all the time, because they are so darn tall and long.
Bruce you should do these from home!
I will be doing them both places
As a windpower experimenter I wanted to know if the surface finish on the Flettner cylinder makes a difference to the force. So I was interested to know if the "square" rotor was better than the circular or not. But you did not say if there was a difference in the force. This is quite important to know as it effects the design of how to get the best rotor. All of the designs of rotors on ships appear to have smooth surfaces, but if they had a dimpled surface like a golf ball would that make them better? Someone needs to do research into this.
The MV Estraden has two operational Flettner rotors on it and the company is claiming about a 6% fuel savings on average for the route it normally runs. That's nothing to scoff at. Initial testing took place in 2015 with one rotor, then another was added increasing fuel savings from over 2% to over 6%.
Their data suggest a similar vessel with larger rotors running the same route, or on other routes, or with ships specifically designed to take advantage of this technology (rather than being retrofitted) might be able to achieve 20% fuel savings (though to date real world tests suggest about a 15% maximum).
This is something some shipping companies are seriously looking into, especially given that we can now construct these rotors from lightweight composite materials that are very strong and computer control systems and various measurement devices are very accurate. Because they take up deck space they can get in the way of cargo, or loading operations, or cause problems when winds are dangerous, so collapsible systems (now also possible due to new materials) are being considered.
There are now many real world examples being tested and in use...
Pictures of the "MV Estraden" (with Flettner rotor retrofit) here: www.marinetraffic.com/en/photos/of/ships/shipid:6000/shipname:ESTRADEN/mmsi:230917000
Pictures of "E SHIP 1", which claims 15% fuel savings on average are here:
www.marinetraffic.com/en/ais/details/ships/shipid:151866/mmsi:218108000/vessel:E%20SHIP%201
Pictures of the Maersk Pelican, an old oil tanker that was refurbished and retrofitted with a larger Flettner system in fall 2018 (with hopes of between 7 and 10% fuel savings) are here: www.marinetraffic.com/en/photos/of/ships/shipid:730851/shipname:MAERSK%20PELICAN/mmsi:565686000
The ferry named Viking Grace had a small system installed in 2018:
www.marinetraffic.com/en/photos/of/ships/shipid:5547/shipname:VIKING%20GRACE/mmsi:230629000
Thanks for the post Derek, I hope I didn't come across as scoffing at the idea of the rotors being used on ships but going back and rewatching my video, I think I did. As you have stated the savings can be significant but the use of the rotors is still in it's infancy compared to the number of ships that could benefit from them but haven't made that commitment. It is a positive note that at least they are actively considering these to help reduce their fuel consumption.
@@YeanyScience Sorry, I didn't mean to use that term in reference to your video specifically, I was using the term to highlight the fact that even knocking off a small percentage of fuel usage is huge when you consider the amount of fuel (and it is a particularly polluting fuel) that a large ship uses.
This is an excellent video that demonstrates the workings of this technology in a way that anyone can test themselves. I can't think of any video of yours that I've watched that didn't impress me. Your ability to break down fairly complex concepts into easily demonstrable experiments using simple materials and to clearly explain what is going on is amazing.
Fettner sails are being installed on large commercial ships to assist in the propulsion by Norsepower Rotor Sails.
Magnus effect for the win(d).
this is on some large sea vessels actually
Thanks Bruce, do you know if the speed of rotation effects the movement speed?
good question, I don't know if there is an ideal speed for the rotation but it is something I would like to test by adding a reostat to it and control the speed. I have a few other ideas that I want to try for it also. There will be a follow up video for this piece
does the car go the other way if the air comes from the other side?
It would be interesting to see the experiment without the spinning rotor(rotor sitting still) like you showed us, but with a wind guard instead of you directing the wind flow with the blower hose. A guard that allows you to have wind applied to the entire device, like the spinning rotor allows, but directs it to only flow past one side of the rotor causing forward motion. To see if it actually can work, if so then you don't need the spinning motor and batteries, but a guard. IT would be a huge experiment finding the right shape guard that will possibly work. If you can direct more stray wind to one side than the other just by shape, then it might move. but then we will find out the sail is already got it all beat. lol But at least we learn more specifics about fluids.
❤️
I worry about the effect of a gale on the tall rotors, but then it occurred to me that they could be telescopic. You would actually be able to "shorten sail" right down. I wonder if this is being done.
Compare the speeds of cart with sails and spinning cylinders
My question is: why not just use a regular sail as it does not require any outside energy? I suppose it means the flettner is only useful in making another source of propulsion more efficient. Ultimately lowering the air pressure in front and increasing it in the back to create forward motion is what makes turboprops and turbojets work anyway. So I presume it’s just about Flettners increasing aerodynamics to not only reduce drag but to use the force of the drag to increase efficiency.
I was hoping he would dangle a spoon into the stream of water flowing from the tap, in which case you will see the spoon being pulled. If you try it, you will feel the effect very noticeably as soon as the spoon hits the stream.
Can you tell me a little bit about the dynamic balancing of flettner rotor? How these big rotors are dynamically balanced?
Do you mean the torque imparted onto the structure of the ship?
Shh... you'll give away my curveball secrets!
Thanks. And what about shoot air only into one side but in the opposite sense of rotation? The car will start to go or not?
Do you mean if the wind comes from the right side of the vehicle instead of the left? Assuming the Flettner rotor is spinning in the same direction (clockwise), the thrust will be toward the rear, and the ship will go backwards.
BUT if the rotation of the Flettner can be reversed, the ship may go forward. THIS is one of my questions to Bruce.
Tesla Turbine explained in Magnus format. It is a shame that more Aircraft do not use this basic idea described by a VERY Smart Man. Please forgive me for my lack of understanding on this subject.
Great show and tell Bruce, Cheers from John, Australia.
The Flettner rotor airplane idea never took off. Hehe
Ed Morales well it did, just didn’t keep flying if the “wing” stopped spinning.
Ed Morales well it did, just didn’t keep flying if the “wing” stopped spinning.
what if instead of spinning the cylinder you cut the cylinder in half with the round side facing forward?
It would look more like a sail.
So... what if regular sails were tubes, pulled tighter across the back to make a semi-cylindrical shape, held apart by ribs.
I'm guessing sailing ships achieve a similar effect just by using multiple sails, and that it's how they manage to sail into a headwind.
Try two rotating in opposite directions then direct the air between them without being driven.
Hmmm. What if…you put vertical cylinders at the rear corners of a car? They could be powered by the wind, and use their spinning to pump air into the wake zone behind the car, decreasing drag.
Additionally, cylinders geared to spin the opposite direction could pump air from the rear diffuser, lowering underbody pressure, increasing downforce.
How would it work as a sail if the wind can just change and ruin everything? (I probably just don't understand fully how it works, please explain if you do
So, if you didn't spin the cylinder, but did block air from hitting the trailing side of it, say with a barrier, would general wind draw it forward? See? Good science teachers get you asking more questions!
In a Magnus turbine the spinning of the tubes is needed? R they start moving with the wind?
Making learning fun
Presumably a frictionless surface would negate the effect?
Hmm, I don’t think so. Friction would slow down the air on the negative pressure side, and that would reduce lift/thrust. I would get out the silicone spray!
Does this mean additional power is needed to course-correct the sideways drift at all times?
I had the same question. I also realized that wind will have some effect on a cargo ship, because they are so darn tall and long.
what is the efficiency of this rotor vs a traditional sail? perhaps that's why it never took off?
From what I read these can make ships about 30% more fuel efficient
Amo los vídeos, pero no entiendo el inglés, no sé qué tanto pedir sea que les coloques subtitulos en español, por favor.
the question is is the motor power required to turn the spinning cylinder more than the power that would be needed if the motor propelled the car or boat at the same speed?
in my example, yes but on a large scale the energy gain from the wind can be 70% greater than the energy needed to turn the masts
@@YeanyScience interesting. Thanks.
What would happen if instead of a crosswind, there was a headwind or tailwind?
good question, tailwind would help any boat's movement, I would guess with a headwind they might change the heading to take advantage of it just like a regular sailboat would do.
Sorry Bruce, I must disagree. The thrust from a Flettner rotor will always be 90° to the wind direction. In a headwind, I think you would stop spinning the Flettner, otherwise it would push you perpendicular to your course. If you were to change course to “take advantage” of the wind coming from your intended destination, you would be going sideways. Cargo ships don’t travel well sideways.
Vectơ lực😉
If 'ridges' are added to the cylinder... it 'feels' like the effect should be greater (due to 'catching' more air) but if I'm understanding the principle correctly, it would actually work less well, since the continuous, smooth flow of air around the curve would be reduced... right?
I think the latter part of your statement is correct. Ribs introduce small vortices. The objective is not to turn the rotor; that’s done mechanically by a separate motor. The objective is to create lower pressure towards the bow (front) of the ship, to create forward thrust.
Skyscrapers no longer go straight up, like The Twin Towers did in New York. The floors change shape as they reach skyward, as the Freedom Tower that was built in its place. This is known as “confusing the wind”.
@@sambrusco672 whats hilarious about this for me is that I wrote that question three years ago, you've just answered it and I literally have NO IDEA what my question even means anymore - I'm gonna have to rewatch and think about this whole thing all over again to even manage to understand what I was asking 🤣
You’re literally the Bill Nye of 2019
this effect used in airsoft guns with hop-up