you are getting close to my design. Thank for showing me the calculator. I'll let you know what my efficiency is after I put a load on my design and will send you the design for all to see. IF millions could build and install them ourselves, we could free ourselves from the power companies. That is my goal, because I hate paying someone else for something I can make/produce myself. Thank you again.
I have a weird idea that I'll just pitch to you. Imagine if the wind going out of those tiny fins at the edge is captured yet Again inside another funnel that redirects the wind to be reused after it already pushed on the initial conic plate and inside that funnel is a set of other blades that the wind can push on again and comes out through holes at the end of the funnel. The reason I'm thinking this way is that the wind going out of those fins at the edges picks up speed and is now even more powerful when you trap it inside a conic funnel it'll increase the power it pushes on the rotor and you'll get even much more power off the wind cause you'll trap it. I can 3D draw it for you if you like. I think it'll be unbelievably powerful. Kudos!
Others claim to break Betz, the claims may not stack up, though one shouldn't diss them for the claim... (usually it is the logic of how to measure which gets broken / altered without due regard). Who we are not worthy of are all the great minds (not all academics and some may even be functionally illiterate) and tinkerers (again not all illiterate and not afew may even be academics - there is practicality all around us ); we never hear about most. TH-cam selects some - few- to become superheros of sorts. Graham Flowers down in the comments - taking umbrage yesterday - claims to break Betz too - he too may be as mad as a bag of kittens, lol, we only know if we test it out (with measurements) PC Fans are a very easy way to test at scale, sadly not everything scales well (Reynolds numbers and vicidity) though with 3d printers,pla and "tinkercad" (or OnShape) readily available we all get to play if we like to.
@@ThinkingandTinkering Thank you for sharing this information with us! There is oh so much information about how we can do things that will help us improve our lives but the best of this information is hidden away from the public so we are chained to the power meter so the rich can keep getting richer off our hard work! If we could use the wind and the solar energy to power our homes. Then we would be able to break the ⛓️ chains and get another hand from pulling out parts our hard earned $$$! Here in the United States the energy costs have more than doubled in the last few years!
@@grahamflowers - thankyou Graham, I appreciate your humor. and good wishes. - At first glance is did appear as if you had Ill feelings towards Mr Betz... (affecting an air of annoyance can be termed "umbrage" - even merely casting shade... - all good..) (No harm in people seeing your creations for themselves, let people see your creations for themselves, it all helps the algorithm (though you can post the links directly into comments - they may not get moderated out as you are not marketing a competing product.)
Such inspirational content. I love seeing the progression with each update. Could you please aim to produce a unit to power charge a battery that could power an electric heater and/or cooker. Off grid self sufficiency without living in a woodland will become a very real need for millions of Britons in the near future.
What’s amazing is I has this exact picture in my mind! I think it’s the real deal Robert. Now sticking it on the Darwin and using the outside torque at the rim will finally create the setup! I bet you could make the Darwin wind funnel bigger at the top and smaller towards the bottom sending more force from air into the smaller surface area for when it hits the cone.
I am guessing that it exceeds the Betz Limit because the flow is non-axial, so the actual effective area is larger than the area of the disk. In any case, it is an awesome result
Likely because the surface area of the turbine is greater than the surface area of the rotor blades. The difference a multiplication of the effective wind velocity far greater than the actual wind speed, due to compression.
I figured the wind exiting a conventional turbine is slower but in the same direction, in this case the wind direction changes from forward to lateral. But maybe I'm just repeating these ideas in a different way haha
@@samuellantela7248 No, that's an interesting idea as well. If Betz limit is based on wind speed vs propeller speed then it would make sense that changing the direction would allow you to reduce wind speed to zero, capturing closer to 100% of the kinetic energy in it.
Would recommend a Prony brake for measuring turbine mechanical power. I've got the code for a ESP32 board to calculate efficiency from a load cell, rpm counter, and anemometer if you want it.
I'm currently working on a Sivonius-type windmill with the same principles as this. I will be printing a stator, which is essentially a tall cylinder with notches for a serpentine coil, and bearings at the top and bottom of the cylinder to hold the axis that will support the Sivonius rotor. The rotor will have embedded magnets so it will also basically be a flywheel and will be positioned over the stator
This is a great video!!! Measuring the increase of the flywheel speed over a given time period (flywheel acceleration) is an excellent way of measuring power. With a very large flywheel and a constant wind speed if accurate RPMs are measure at predetermined time intervals (10 seconds), then the flywheel acceleration (RPMs per second) can be determined between zero and maximum RPM. Usually the acceleration curve follows a bell curve with the most power being produced at about 1/2 the maximum RPM.
Absolutely great question about the Betz limit! A great question for all engineers to understand and answer. I will give it a go.... I believe mistake is to measure the wind speed directly in front of the turbine. At this point (according to Betz theory), some of the air has already deviated around the turbine so, while the speed may be correct, the actual area of the moving air is greater, i.e. wind power is greater so overall efficiency is less. There are a number of alternate measurements possible: 1) Measure the airspeed directly out of the blower and multiply by the blower area. This will give a better measure of supplied energy 2) Measure the airspeed a slight distance (say 5cm) away from the turbine, but take many points moving away from the centre of the turbine. This way, a more realistic determination of the area of the air stream can be determined. Chances are, the area over which the air speed is ~2m/s (or whatever you measured) is greater than what you have assumed. Repeat for many distances from the turbine and with air speed readings at many locations. 3) Don't turn on the blower at t=0... have it already on but hold the turbine from moving. 4) Check air speed (as per suggestion 2) with the turbine moving and with the turbine stationary 5) Measure the turbine speed over time.. Theoretically the turbine speed should increase as square root function? If not, the turbine speed is over speed and maybe a bigger fly wheel is required. ... why not try in your "spare" time?
or you could try - i can think of criticism to what you are arguing - one being as it exits the blower it has more energy than the energy it would have when it hits the turbine - number 3 - i did that!
Great videos to learn all about wind and water power. Another experiment: What if you worked on the surface of your router? If you coated it with Teflon or other materials to make the surface really, really smooth and slick, you might get 90% efficiency.
I love how this crazy guy proves that we are crazy because whe are not as excited about motors as he. Thank you very much for sharing this excitement with the world. We need more rolemodels like this.
The greatest lie in science today is that all the big discoveries have already been made; that the big breakthroughs require massive teams and millions in funding. There are so many paths that are only unexplored because we've convinced ourselves there's nothing to be found.
While there are tons of various factors in this, mass acceleration [ 1 grav accelerates 1 unit of mass 32 feet per second, per second ] which is on the input side of things, general turbulence and mechanical drag [in this case, mainly just the bearings, as the overall rotational speed is not super much] and the counter thrust if the air as it rotates out of the initial fan source [which matters very little in this exact format, I am sure, but can be greatly affected with some deliberately placed rotary vanes]. Basically, the same way there are diverter/corrector/stator vanes inside of an axial flow turbine engine, one can do the same, mounting little stationary blades, along a tube, in front of your turbine, which act to force the air the direction you wish the turbine to spin. They have something a little bit like this on some turbochargers to reduce turbo lag, and they work simply by making sure that the air hits the impeller of the turbocharger at a tighter, steeper, more tangential velocity, therefore, importing more rotational torque, more efficiently. While there is a practical limit to this, it is something that even in very small amounts will make measurable gains for the same flow of air [or water, or even sand] across a flow vane like this.
You need to put a length of pipe on the output of your fan to feed the column of air directly onto the test turbine. That way you can get a more efficient feed system and a more consistent way of feeding the air. You can also intercept the column of air at a more consistent and repeatable place...either make a slot in the tube and poke the meter through or place it on the exit of the feeder pipe.
One thing to do would be to test with the exact same setup but with conventional blades of the same diameter. That would tell you if something is off with your calculations/test setup or it you actually did create a much more efficient turbine.
Would need a model for small-scale turbines, or a turbine/blade design of known performance given known size and construction, but yes that'd give a method to calibrate the flywheel measurement system
Fascinating and ingenious! I surmise that the apparent surpassing of the Betz limit can be attributed to the use of the disc's diameter as the swept area, while the air flowing around the disc contributes additional energy. As the slower moving air emerges around the disc's edge, it would be carried away by the wind flowing around it. This process would decelerate the surrounding air, effectively increasing the swept area without the need for physically larger blades. In essence, this approach leverages the air itself as blades. 🙂
The distribution on the flywheel is also important - the flywheel is out of PLA and on the rim are neodymium magnets - that means the stored energy is higher...
I will print it but I think that I will need some addional part like ball bearing and also a generator to rotate and see the efficiency without the flywheel and so more precise calculation I guess. Newbie on this youtube channel and very nice to see all of this idea to build and improve :)
Thanks for fixing the title, the weong number was really messing with my OCD. I love your videos, just bought a 3d printer to try out your designs. Always a tinkerer.
You have cool videos that inspire more innovation. I see things that can be made in front of turbine and behind to increase capabilties, like that wind collector in your other video. Behind it can use the "waste" wind, any airflow that interacted with the turbine and store it as you did with your flywheel tester. Analogous to using multiple mirrors to reflect sunlight to one focus. There's a way to store energy in the wind and a vortex is such a way. Don't stop converting wind energy at the end of your turbine blade. Since the wind coming off the turbine is somewhat controlled it offers the opportunity to extract more energy by continuing to control it in a stationary vortex. Because the vortex is not moving it stores energy that is directed to another turbine which is very similar to your design. I saw the definition of Betz limit. 59% at converting wind to "electricity". 80% is not electrical conversion.
It should be noted that your moment of inertia is probably even higher than what the calculator came up with was more of your mass is towards the rim of the flywheel, which will increase the moment of inertia over a homogenous disc. It will probably be even higher still if you account for the inertia of the other spinning components in the assembly as well.
Robert, you are awesome. If you lived next door we’d be hanging out getting into trouble. 2 thoughts: Couldn’t the mass of rotor (and shaft, anything spinning) be added to mass flywheel when calculating energy? Your energy calculation used mass, but didn’t account for distance mass is from center, (moment of inertia, but not positive on terminology).
I just came across your channel a month or two ago. I'm not an engineer of any type, just an artist and cook. I've been watching all these experiments on the darwin turbine and am fascinated by the potential where I live. I'm on the coast of Maine, and this could help me go off grid in combination with solar. I can't wait for some real-world data! Keep up the great work!
Hello Robert! That rotor is reminiscent of the front end of a jet engine hanging off an aircraft. Aerodynamic engineers been reading the same material? Word for the day - Quaquaversal: radiating in all directions from a central point.
Thanks. Always enjoy your work. Regarding the limit are we comparing the same thing? Airflow is power kgs/sec flywheel is kinetic energy the joules will keep accumulate until losses happen. Thanks for your vidoes rob.
What about keeping the part of the fins that the air enters the same and shortening the part that the air exits. Basically make a bit of a funnel between the top ring and the base to increase air speed. The air coming out should push it around like little jets.
id love to see a complete wind turbine up and running, something we can all build and complete cheaply, to add to our hoses and batteries o store the much needed energy these days, with the current prices. I have solar and battery and would love a few of these turbines up and running ready for the winter when the solar gives out very little.
super! je me demande si cette forme peut être mise sur la tête de ma trompe à eau... avec un diamètre pvc 200mm; j'ai un bon volume d'air expulsé (mais peu de pression). penses-tu que cette géométrie soit optimisée pour produire quelques watts? (ou as-tu à l'esprit une autre turbine plus efficace pour le genre de configuration...?) ps: votre chaîne est géniale!
All the math. All the thought. All the design and CAD and printing. You couldn’t think to add ways to put these devices on a stand. Love the knowledge. Keep up the great work.
Your turbine is an Explosions, not an implosion. You could also say centrifugal not a centripetal turbine. That's why it wastes so much energy. It doesn't compress the end it just Pushes it out of the way
Interesting. What would happen if you added contours to the cone to create a vortex rather than relying purely on the angle of the blades for rotation?
I've built wind turbines for over 50 years. Your design, scaled up, would be tantamount to having a full sheet of plywood facing the wind. The higher the tower, the GREATER the moment arm (leverage) on the tower. It will sooner than later fall to the ground. Ultimately, I have found the less mass up in the wind, the better, which is why I use Darius/Savonious VAWTs exclusively.
I wonder if it's possible to create a completely natural artificial wind weather in a room with alternating temperatures to create a miniature tornado in the center of the room to spin it by using the ancient heat siphon method used in architecture called windcatcher buildings in hot environments where a well at the bottom brings cold air back to the surface as hot air passes it. Edit: Room/Exterior Round Plaza
I think a longer cone diverter would help. It seems the diskblade or rimblade simply collects more wind and its energy, and should have more output power. The air collision with the cone will reduce some of the wind energy. Update, maybe yours has a more torque since the wind is striking a rimblade in a right angle like direction to the radius, plus there are so many blades doing the same. Not many tools and materials here, but paper index cards and glue, and a fan might be a way. What is neat about that turbine, is that it has qualities of both vawt and hawt. A neat thing to do would be a funnel on the front to collect more wind energy.
@@alexd7466 I'm dot sure, maybe a 30 to 45 degree, curved cone, but it's height needs experimentation. Could be a flop anyway, but the data would be of value.
@Michael Hansen Hi Michael, Some simple energy maths may help you decide if roof water really makes sense. First some assumptions: I’m basing this on an annual rainfall of 2.4m which is at the extreme upper limit for rainfall, pretty much anywhere in Europe or North America: secondly, I’m assuming a two storey house of 250m² (2,600ft²) with a roof of 125m² and a vertical drop from gutter to turbine of 5m. Now the maths. The total volume of water falling on the roof in a year is 125 x 2.4 = 300m³ = 300,000 litres with a mass of 300,000kg. This water has a total gravitational potential energy [E=m.g.h] equal to its mass 300,000 x g (~10) x 5, the vertical head. E = ~15,000,000 J. At 100% efficiency that amounts to about 4.2 kW.h (units) of electricity per year! Where I live that’s about a dollar fifty from the grid. For reasons, which I’ll go into in another post if you want me to, I am very doubtful if you could convert even 30% of that to electrical power, but even if you did and you got 5,000,000 J out, that works out to a continuous power supply of about 0.158 Watts (158 milliWatts). And to do that you’ve got to make a system that can extract efficient levels of energy from both a light rain and a downpour. We can go into the difficulty of that, too, if you want to. Remember, too, the rainfall I used was about as wet as it gets unless you live in a famously wet place. It’s my opinion that roof water is really not worth pursuing as an energy source. A 200W solar panel puts out 5,040,000J in just 7 hours of sunshine, and you could fit 50 - 60 of them on that same roof.
Could the reason for the above-the-betz limit results be that (and I'm drawing from the logic that the betz limit is founded upon I believe) since the betz limit assumes that by blocking the whole area of the turbine, no air will be able to pass through, and thus the turbine won't generate energy, and since your turbing DOES block all the air hitting the area of the turbine, letting it pass through the sides, it can capture even more energy since there will actually be a LARGE speed difference between the intake and output of air rather than the approximately equal speed difference with an ordinary turbine (because the air spreads out) Using this logic, I could argue that the best turbine design would be one that takes a small opening size and manages to spread the air out as much as possible, perhaps by opening up the center of the turbine as well as the sides. Maybe the lily impeller (golden ratio turbine) could work for this as it makes for a very smooth transition between fast moving input and slow moving output... Of course, doing this all without drastically increasing the material used in a turbine would be very hard and I'm not sure how this could be applied to large scale turbines but if you can find a way to make this work for micro generation it would be absolutely amazing Please correct me if i'm wrong with anything because I probably am (grade 10 high school student with limited physics knowledge here), but I feel that you may have very well broken the betz limit fair and square without breaking the laws of thermodynamics. Amazing work! Have a great day!
All hail sir robert of Canterbury who hath proveth there are no limits in science, only in the imaginations of man! Nice one mate, I actually think your design is even more efficient as if you watch the video back, the fan is actually slightly angled higher and the column of air coming out seems to hit about from the middle of the blade and up with perhaps a little over spread meaning your calculation is based on only 50% of the blade or just over being hit by the available wind. Which is mind boggling considering what you got out. If im right you've not only broken the betz limit but broken the laws of whats possible. (As we currently understand)
Betz assumes 1D axial flow. Max power extraction happens at Vout = 1/3 Vin. Robert, you have a 2D system, axial & radial. Your axial out velocity is zero and you don’t choke the system because your shroud creates a radial out path. I think…
I think you have a problem with the online calculator, relating to the density distribution in your flywheel, as the densest parts are the magnets around the rim. If as I suspect the calculator assumes a solid disc of equal density then your turbine is even more efficient, which either means because the air flow is turned nearly 90 degrees the Betz limit does not apply, or your measurements/calculations are suspect, I am hoping the first theory applies as I generally trust your work (even when your enthusiasm gets the better of you). By the way that is not a criticism, I really enjoy watching someone genuinely enjoying the practical application of science, there are so few of us about with the knowledge, time and the tools to play with our ideas.
Just a few points 1 this still suffers from the problem of Kinetic Energy in the wind being proportional to the cube of wind velocity . Half the velocity 1/8th the energy. 2 This is a solid rotor, the pressure in change wind flow through 90' will be very high. Size limitingly? 3 the wind shadow will be very large due wind being diverted in all directions 4 wind will be diverted directly onto the ground what effect will that have. 5 due to 3 & 4 will it be possible to have an array 6 due to 3 & 4 what will be the effect on local climate, eg reduced wind speed = less ground evaporation Not being negative as it's an impressive bit of kit I assume the fly wheel is for experimental purposes only? Because it would overcome the problem of lack of inertia in the current generation of turbines which is a problem for grid stability as I understand it
Hi Rob, what you have done is you are using ALL the pressure generated by the wind and insread of the wind passing between the normal vawt it is directed to the blades at the end. Why not extend the blades in another parabolic path to the middle of the turbine? Like that you will increase the force of the wind on the turbine dramatically? Hard to explain what I mean here, Something like an impeller?B
robert....why dont you isolate the system, use a rotor with similar size to the fan outlet and stick a pipe between the rotor and outlet, doing this will eliminate possibe error sources such as an unknown source of venturi effect pulling air from the sides
There's the cross sectional area, and then there is the effective cross sectional area. 😊 As the air is diverted by the turbine to an angle that is 90 degrees to the wind, the air has momentum and presents sort of like a wall that extends beyond the turbine's physical cross section, thus there builds up a slightly higher pressure zone in front and a lower pressure zone behind. Storing 1.2 joules of energy and calculating 80% of the available energy. that's very impressive, but I suspect that maybe there is a significant margin of error. With these small numbers.
in calculation of the area of your wind capture device did you use total area? as I watched it I noticed that the blades have a flat cover the only effective capture area is inside too inside of the blades. not meaning to disrespect this is a great design 👌 cheers Robert
@Robert Murray-Smith is the video's number correct? You also refer to video 1921 3:12 , which I thought this was. I can't tell if I'm simply misunderstanding something.
you are getting close to my design. Thank for showing me the calculator. I'll let you know what my efficiency is after I put a load on my design and will send you the design for all to see. IF millions could build and install them ourselves, we could free ourselves from the power companies. That is my goal, because I hate paying someone else for something I can make/produce myself. Thank you again.
:)
I have a weird idea that I'll just pitch to you. Imagine if the wind going out of those tiny fins at the edge is captured yet Again inside another funnel that redirects the wind to be reused after it already pushed on the initial conic plate and inside that funnel is a set of other blades that the wind can push on again and comes out through holes at the end of the funnel. The reason I'm thinking this way is that the wind going out of those fins at the edges picks up speed and is now even more powerful when you trap it inside a conic funnel it'll increase the power it pushes on the rotor and you'll get even much more power off the wind cause you'll trap it. I can 3D draw it for you if you like. I think it'll be unbelievably powerful. Kudos!
we are not worthy, phisics broken: today marks the First day, of the age of measuring wind turbine efficiency in "Murry Smiths"
lol - cheers mate
Others claim to break Betz, the claims may not stack up, though one shouldn't diss them for the claim...
(usually it is the logic of how to measure which gets broken / altered without due regard).
Who we are not worthy of are all the great minds (not all academics and some may even be functionally illiterate) and tinkerers (again not all illiterate and not afew may even be academics - there is practicality all around us ); we never hear about most. TH-cam selects some - few- to become superheros of sorts.
Graham Flowers down in the comments - taking umbrage yesterday - claims to break Betz too - he too may be as mad as a bag of kittens, lol, we only know if we test it out (with measurements)
PC Fans are a very easy way to test at scale, sadly not everything scales well (Reynolds numbers and vicidity) though with 3d printers,pla and "tinkercad" (or OnShape) readily available we all get to play if we like to.
@@ThinkingandTinkering Thank you for sharing this information with us! There is oh so much information about how we can do things that will help us improve our lives but the best of this information is hidden away from the public so we are chained to the power meter so the rich can keep getting richer off our hard work!
If we could use the wind and the solar energy to power our homes. Then we would be able to break the ⛓️ chains and get another hand from pulling out parts our hard earned $$$!
Here in the United States the energy costs have more than doubled in the last few years!
Build a donutspere around the cone. With the top hole facing to the sky
@@grahamflowers - thankyou Graham, I appreciate your humor. and good wishes.
- At first glance is did appear as if you had Ill feelings towards Mr Betz... (affecting an air of annoyance can be termed "umbrage" - even merely casting shade... - all good..)
(No harm in people seeing your creations for themselves, let people see your creations for themselves, it all helps the algorithm (though you can post the links directly into comments - they may not get moderated out as you are not marketing a competing product.)
"Mad as a bag of kittens" Good show, great job.😄
I look at all these cool videos of yours and and wish that I could be your apprentice.
Much respect for you Robert!
Such inspirational content. I love seeing the progression with each update.
Could you please aim to produce a unit to power charge a battery that could power an electric heater and/or cooker.
Off grid self sufficiency without living in a woodland will become a very real need for millions of Britons in the near future.
He’s teaching you how to do it dummy!
"Mad as a bag of kittens" I doubt it!! You are feeding people's minds....well done!
wow cheers mate
It's like you break down problems and build the solutions using modular logic.
Legotastic, man
What’s amazing is I has this exact picture in my mind! I think it’s the real deal Robert. Now sticking it on the Darwin and using the outside torque at the rim will finally create the setup! I bet you could make the Darwin wind funnel bigger at the top and smaller towards the bottom sending more force from air into the smaller surface area for when it hits the cone.
If you are “mad as a bag of kittens” please keep it up! Your videos are informative and amusing. I love watching them.
lol - cheers mate
I am guessing that it exceeds the Betz Limit because the flow is non-axial, so the actual effective area is larger than the area of the disk. In any case, it is an awesome result
My thinking too. The assumptions for the Betz don't allow for the air to exit to the side after passing through the actuator.
Likely because the surface area of the turbine is greater than the surface area of the rotor blades. The difference a multiplication of the effective wind velocity far greater than the actual wind speed, due to compression.
I figured the wind exiting a conventional turbine is slower but in the same direction, in this case the wind direction changes from forward to lateral. But maybe I'm just repeating these ideas in a different way haha
@@samuellantela7248 No, that's an interesting idea as well.
If Betz limit is based on wind speed vs propeller speed then it would make sense that changing the direction would allow you to reduce wind speed to zero, capturing
closer to 100% of the kinetic energy in it.
Man! You're just simply beautiful.. Thanks for just being there in there world!
Some of the dictums I learnt from a mentor "To measure is to know" and "You can't manage what you don't know!".
nice
Would recommend a Prony brake for measuring turbine mechanical power. I've got the code for a ESP32 board to calculate efficiency from a load cell, rpm counter, and anemometer if you want it.
I'm currently working on a Sivonius-type windmill with the same principles as this. I will be printing a stator, which is essentially a tall cylinder with notches for a serpentine coil, and bearings at the top and bottom of the cylinder to hold the axis that will support the Sivonius rotor. The rotor will have embedded magnets so it will also basically be a flywheel and will be positioned over the stator
Doubling the turbine rotor as a generator rotor is such an elegant design. Nice.
@@wildekek thank you
nice mate
Thanks 4 providing the wind speed 4 us as it will help 4 our calculations per a previous video!!!
Absolutely amazing, love it, well done Robert :D
cheers mate
I like these videos; they look like the good ol' days of 'in the kitchen'. Awesome Rob!
I would wager that Mr. Betz never met a tornado that he couldn't control the power of.
This is a great video!!! Measuring the increase of the flywheel speed over a given time period (flywheel acceleration) is an excellent way of measuring power.
With a very large flywheel and a constant wind speed if accurate RPMs are measure at predetermined time intervals (10 seconds), then the flywheel acceleration (RPMs per second) can be determined between zero and maximum RPM. Usually the acceleration curve follows a bell curve with the most power being produced at about 1/2 the maximum RPM.
Brilliant video.
Absolutely great question about the Betz limit! A great question for all engineers to understand and answer. I will give it a go....
I believe mistake is to measure the wind speed directly in front of the turbine. At this point (according to Betz theory), some of the air has already deviated around the turbine so, while the speed may be correct, the actual area of the moving air is greater, i.e. wind power is greater so overall efficiency is less.
There are a number of alternate measurements possible:
1) Measure the airspeed directly out of the blower and multiply by the blower area. This will give a better measure of supplied energy
2) Measure the airspeed a slight distance (say 5cm) away from the turbine, but take many points moving away from the centre of the turbine. This way, a more realistic determination of the area of the air stream can be determined. Chances are, the area over which the air speed is ~2m/s (or whatever you measured) is greater than what you have assumed. Repeat for many distances from the turbine and with air speed readings at many locations.
3) Don't turn on the blower at t=0... have it already on but hold the turbine from moving.
4) Check air speed (as per suggestion 2) with the turbine moving and with the turbine stationary
5) Measure the turbine speed over time.. Theoretically the turbine speed should increase as square root function? If not, the turbine speed is over speed and maybe a bigger fly wheel is required.
... why not try in your "spare" time?
or you could try - i can think of criticism to what you are arguing - one being as it exits the blower it has more energy than the energy it would have when it hits the turbine - number 3 - i did that!
Cool, I reckon the flywheel would also act as a gyroscope. In a VAWT situation, the flywheel may add to stability in higher winds. 🤔
Thank you Rob
Science requires scientists. Thank you!
Great videos to learn all about wind and water power. Another experiment: What if you worked on the surface of your router? If you coated it with Teflon or other materials to make the surface really, really smooth and slick, you might get 90% efficiency.
Amazing! I take it on faith, but this is perfect! I can see the design has a wind collecting feature. The is the best engineering since Adrian Newey.
I love how this crazy guy proves that we are crazy because whe are not as excited about motors as he.
Thank you very much for sharing this excitement with the world.
We need more rolemodels like this.
The greatest lie in science today is that all the big discoveries have already been made; that the big breakthroughs require massive teams and millions in funding.
There are so many paths that are only unexplored because we've convinced ourselves there's nothing to be found.
While there are tons of various factors in this, mass acceleration [ 1 grav accelerates 1 unit of mass 32 feet per second, per second ] which is on the input side of things, general turbulence and mechanical drag [in this case, mainly just the bearings, as the overall rotational speed is not super much] and the counter thrust if the air as it rotates out of the initial fan source [which matters very little in this exact format, I am sure, but can be greatly affected with some deliberately placed rotary vanes].
Basically, the same way there are diverter/corrector/stator vanes inside of an axial flow turbine engine, one can do the same, mounting little stationary blades, along a tube, in front of your turbine, which act to force the air the direction you wish the turbine to spin.
They have something a little bit like this on some turbochargers to reduce turbo lag, and they work simply by making sure that the air hits the impeller of the turbocharger at a tighter, steeper, more tangential velocity, therefore, importing more rotational torque, more efficiently.
While there is a practical limit to this, it is something that even in very small amounts will make measurable gains for the same flow of air [or water, or even sand] across a flow vane like this.
Thank you very much 🌹
You need to put a length of pipe on the output of your fan to feed the column of air directly onto the test turbine.
That way you can get a more efficient feed system and a more consistent way of feeding the air.
You can also intercept the column of air at a more consistent and repeatable place...either make a slot in the tube and poke the meter through or place it on the exit of the feeder pipe.
One thing to do would be to test with the exact same setup but with conventional blades of the same diameter. That would tell you if something is off with your calculations/test setup or it you actually did create a much more efficient turbine.
Exactly my thoughts.
cheers mate
Would need a model for small-scale turbines, or a turbine/blade design of known performance given known size and construction, but yes that'd give a method to calibrate the flywheel measurement system
Can't wait to see/try this with a shroud! 💪💪
Fascinating and ingenious! I surmise that the apparent surpassing of the Betz limit can be attributed to the use of the disc's diameter as the swept area, while the air flowing around the disc contributes additional energy. As the slower moving air emerges around the disc's edge, it would be carried away by the wind flowing around it. This process would decelerate the surrounding air, effectively increasing the swept area without the need for physically larger blades. In essence, this approach leverages the air itself as blades. 🙂
interesting mate thank you for the ideas
Looks great, keep it up!
This coupled with the air flow design from video 1901 may have potential, finding the sweet spot for the nose of the cone is the key.
The distribution on the flywheel is also important - the flywheel is out of PLA and on the rim are neodymium magnets - that means the stored energy is higher...
cheers mate
Thanks! :) Measurements are good.
cheers
Very cool! It seems there should be vacuum energy downwind of the disk that could be exploited
I will print it but I think that I will need some addional part like ball bearing and also a generator to rotate and see the efficiency without the flywheel and so more precise calculation I guess. Newbie on this youtube channel and very nice to see all of this idea to build and improve :)
yes it will
Thanks for fixing the title, the weong number was really messing with my OCD.
I love your videos, just bought a 3d printer to try out your designs. Always a tinkerer.
I wonder how the effect of upscaling it would perform. Another video that makes one think. Thanks Robert.
go for it
Your content ignites my brain!
You have cool videos that inspire more innovation. I see things that can be made in front of turbine and behind to increase capabilties, like that wind collector in your other video. Behind it can use the "waste" wind, any airflow that interacted with the turbine and store it as you did with your flywheel tester. Analogous to using multiple mirrors to reflect sunlight to one focus. There's a way to store energy in the wind and a vortex is such a way. Don't stop converting wind energy at the end of your turbine blade. Since the wind coming off the turbine is somewhat controlled it offers the opportunity to extract more energy by continuing to control it in a stationary vortex. Because the vortex is not moving it stores energy that is directed to another turbine which is very similar to your design. I saw the definition of Betz limit. 59% at converting wind to "electricity". 80% is not electrical conversion.
It should be noted that your moment of inertia is probably even higher than what the calculator came up with was more of your mass is towards the rim of the flywheel, which will increase the moment of inertia over a homogenous disc. It will probably be even higher still if you account for the inertia of the other spinning components in the assembly as well.
yes - the error i made were in favour of the betz limit
Robert, you are awesome. If you lived next door we’d be hanging out getting into trouble.
2 thoughts:
Couldn’t the mass of rotor (and shaft, anything spinning) be added to mass flywheel when calculating energy?
Your energy calculation used mass, but didn’t account for distance mass is from center, (moment of inertia, but not positive on terminology).
I just came across your channel a month or two ago. I'm not an engineer of any type, just an artist and cook. I've been watching all these experiments on the darwin turbine and am fascinated by the potential where I live. I'm on the coast of Maine, and this could help me go off grid in combination with solar. I can't wait for some real-world data! Keep up the great work!
Excellent work. I would love to see how this would function in some type of staggered array..
Good stuff Rob! 🎉
cheers mate
Hello Robert!
That rotor is reminiscent of the front end of a jet engine hanging off an aircraft.
Aerodynamic engineers been reading the same material?
Word for the day - Quaquaversal: radiating in all directions from a central point.
Great idea for a rotor
Thanks. Always enjoy your work. Regarding the limit are we comparing the same thing? Airflow is power kgs/sec flywheel is kinetic energy the joules will keep accumulate until losses happen. Thanks for your vidoes rob.
What about keeping the part of the fins that the air enters the same and shortening the part that the air exits. Basically make a bit of a funnel between the top ring and the base to increase air speed. The air coming out should push it around like little jets.
I like it. Love to see a big one.
build one
Betz also only accounts for upstream and downstream air velocity. This disk eliminates downstream air velocity.
good point mate - thank you for mentioning it
id love to see a complete wind turbine up and running, something we can all build and complete cheaply, to add to our hoses and batteries o store the much needed energy these days, with the current prices. I have solar and battery and would love a few of these turbines up and running ready for the winter when the solar gives out very little.
there are loads of them mate - just copy one if you want one
Congratulations, I hope it pans out. We would get the Murray limit. Forget about Betz. Maybe the Murray maximum would sound better.
Nice, you're really fine tuning
cheers mate
If you think about it, it looks just like the intake of high powered, Mach flying jets. So you're actually on to something.
super!
je me demande si cette forme peut être mise sur la tête de ma trompe à eau...
avec un diamètre pvc 200mm; j'ai un bon volume d'air expulsé (mais peu de pression).
penses-tu que cette géométrie soit optimisée pour produire quelques watts? (ou as-tu à l'esprit une autre turbine plus efficace pour le genre de configuration...?)
ps: votre chaîne est géniale!
All the math. All the thought. All the design and CAD and printing. You couldn’t think to add ways to put these devices on a stand. Love the knowledge. Keep up the great work.
?
Good one!
cheers mate
Thanks a lot...
Your turbine is an Explosions, not an implosion. You could also say centrifugal not a centripetal turbine. That's why it wastes so much energy. It doesn't compress the end it just Pushes it out of the way
I noticed a bit of a wobble in the rotor. Could this have an effect on the measurements? Especially, if it were to be scaled up to a useful size?
It would be great to see a smoke test to see how much of the wind energy is actually going through the blades. great video though!!
build one and do it
You should try the simple plastic sheet folded into a pinwheel! Lightweight, so it should be more efficient and you might get more speed, perhaps!
Interesting. What would happen if you added contours to the cone to create a vortex rather than relying purely on the angle of the blades for rotation?
Hi do you think the brachistochrone curve might work better for the collector profile?
Cor. You are an absolute unit of an inventor. Thank you so much for sharing your work. It's truly God's Work.
I'm hoping you're planning on encasing that flywheel and stick the giant darwin turbine on it.
Amazing video already and I'm only just buffering :D
lol - cheers mate
@@ThinkingandTinkering I sent you a patent in the mail too ;)
It's like an axial compressor in reverse
The numbering of this video seems to be off considering the last video was 1920 and this video referenced video 1921. Thanks for the content!
corrected mate
I've built wind turbines for over 50 years. Your design, scaled up, would be tantamount to having a full sheet of plywood facing the wind. The higher the tower, the GREATER the moment arm (leverage) on the tower. It will sooner than later fall to the ground.
Ultimately, I have found the less mass up in the wind, the better, which is why I use Darius/Savonious VAWTs exclusively.
He's planning on using it in a Darwin turbine so it will be installed vertical
Is there a formula for mass if the fly wheel to rotar combination. Ie. If the flywheel is to heavy then the rotor won't turn it.
Off topic, but where did you get that plant pot from? Its really nice and I would love to get one for my juniper Bonsai.
Wow sir bag of kittens 😂
I wonder if it's possible to create a completely natural artificial wind weather in a room with alternating temperatures to create a miniature tornado in the center of the room to spin it by using the ancient heat siphon method used in architecture called windcatcher buildings in hot environments where a well at the bottom brings cold air back to the surface as hot air passes it.
Edit: Room/Exterior Round Plaza
What do they say about fine lines between madness and genius?
Excellent work, Sir. Thanks
I think a longer cone diverter would help. It seems the diskblade or rimblade simply collects more wind and its energy, and should have more output power. The air collision with the cone will reduce some of the wind energy.
Update, maybe yours has a more torque since the wind is striking a rimblade in a right angle like direction to the radius, plus there are so many blades doing the same.
Not many tools and materials here, but paper index cards and glue, and a fan might be a way.
What is neat about that turbine, is that it has qualities of both vawt and hawt. A neat thing to do would be a funnel on the front to collect more wind energy.
that also means more resistance, so I assume it should be kept at small as possible (but not any smaller)
build one
@@ThinkingandTinkering Thanks. Another idea to do Betz limit research is to affix hawt blades on the front of it.
@@alexd7466 I'm dot sure, maybe a 30 to 45 degree, curved cone, but it's height needs experimentation. Could be a flop anyway, but the data would be of value.
Very interesting, I wonder how that rotor would perform in a rain water downspout. I live in a very wet area and always think about that potential.
i don't know - try it and let me know
Put some storage medium near the top of the spout and capture the maximum amount.
Air water go hand in 👌 hand
Stack them decrease exit hole force water in center of next rotor,one goes out disconnect one put in straight pipe tell one broken is fixed
@Michael Hansen
Hi Michael,
Some simple energy maths may help you decide if roof water really makes sense.
First some assumptions: I’m basing this on an annual rainfall of 2.4m which is at the extreme upper limit for rainfall, pretty much anywhere in Europe or North America: secondly, I’m assuming a two storey house of 250m² (2,600ft²) with a roof of 125m² and a vertical drop from gutter to turbine of 5m.
Now the maths. The total volume of water falling on the roof in a year is 125 x 2.4 = 300m³ = 300,000 litres with a mass of 300,000kg.
This water has a total gravitational potential energy [E=m.g.h] equal to its mass 300,000 x g (~10) x 5, the vertical head. E = ~15,000,000 J. At 100% efficiency that amounts to about 4.2 kW.h (units) of electricity per year! Where I live that’s about a dollar fifty from the grid.
For reasons, which I’ll go into in another post if you want me to, I am very doubtful if you could convert even 30% of that to electrical power, but even if you did and you got 5,000,000 J out, that works out to a continuous power supply of about 0.158 Watts (158 milliWatts). And to do that you’ve got to make a system that can extract efficient levels of energy from both a light rain and a downpour. We can go into the difficulty of that, too, if you want to.
Remember, too, the rainfall I used was about as wet as it gets unless you live in a famously wet place.
It’s my opinion that roof water is really not worth pursuing as an energy source. A 200W solar panel puts out 5,040,000J in just 7 hours of sunshine, and you could fit 50 - 60 of them on that same roof.
What if using high pressure water gravity, wiil this turbine spin faster?
Have you thought about making the blades taller and tapering them towards the centre
Could the reason for the above-the-betz limit results be that (and I'm drawing from the logic that the betz limit is founded upon I believe) since the betz limit assumes that by blocking the whole area of the turbine, no air will be able to pass through, and thus the turbine won't generate energy, and since your turbing DOES block all the air hitting the area of the turbine, letting it pass through the sides, it can capture even more energy since there will actually be a LARGE speed difference between the intake and output of air rather than the approximately equal speed difference with an ordinary turbine (because the air spreads out)
Using this logic, I could argue that the best turbine design would be one that takes a small opening size and manages to spread the air out as much as possible, perhaps by opening up the center of the turbine as well as the sides. Maybe the lily impeller (golden ratio turbine) could work for this as it makes for a very smooth transition between fast moving input and slow moving output... Of course, doing this all without drastically increasing the material used in a turbine would be very hard and I'm not sure how this could be applied to large scale turbines but if you can find a way to make this work for micro generation it would be absolutely amazing
Please correct me if i'm wrong with anything because I probably am (grade 10 high school student with limited physics knowledge here), but I feel that you may have very well broken the betz limit fair and square without breaking the laws of thermodynamics. Amazing work! Have a great day!
One of many
True genius is not inventing the wheel it is figuring out all the uses for it.
All hail sir robert of Canterbury who hath proveth there are no limits in science, only in the imaginations of man! Nice one mate, I actually think your design is even more efficient as if you watch the video back, the fan is actually slightly angled higher and the column of air coming out seems to hit about from the middle of the blade and up with perhaps a little over spread meaning your calculation is based on only 50% of the blade or just over being hit by the available wind. Which is mind boggling considering what you got out. If im right you've not only broken the betz limit but broken the laws of whats possible. (As we currently understand)
cheers mate
If you had a Darwin setup with the air flowing upwards, would a Gruchinsky (?) fan on top of the rotor impede its speed or assist its rotation?
Betz assumes 1D axial flow. Max power extraction happens at Vout = 1/3 Vin. Robert, you have a 2D system, axial & radial. Your axial out velocity is zero and you don’t choke the system because your shroud creates a radial out path. I think…
cheers mate
I think you have a problem with the online calculator, relating to the density distribution in your flywheel, as the densest parts are the magnets around the rim.
If as I suspect the calculator assumes a solid disc of equal density then your turbine is even more efficient, which either means because the air flow is turned nearly 90 degrees the Betz limit does not apply, or your measurements/calculations are suspect, I am hoping the first theory applies as I generally trust your work (even when your enthusiasm gets the better of you).
By the way that is not a criticism, I really enjoy watching someone genuinely enjoying the practical application of science, there are so few of us about with the knowledge, time and the tools to play with our ideas.
Just a few points
1 this still suffers from the problem of Kinetic Energy in the wind being proportional to the cube of wind velocity . Half the velocity 1/8th the energy.
2 This is a solid rotor, the pressure in change wind flow through 90' will be very high. Size limitingly?
3 the wind shadow will be very large due wind being diverted in all directions
4 wind will be diverted directly onto the ground what effect will that have.
5 due to 3 & 4 will it be possible to have an array
6 due to 3 & 4 what will be the effect on local climate, eg reduced wind speed = less ground evaporation
Not being negative as it's an impressive bit of kit I assume the fly wheel is for experimental purposes only? Because it would overcome the problem of lack of inertia in the current generation of turbines which is a problem for grid stability as I understand it
could the angle or shape of the blades improve this
wind foil shape fan blades might increase performance 😊
Hi Rob, what you have done is you are using ALL the pressure generated by the wind and insread of the wind passing between the normal vawt it is directed to the blades at the end. Why not extend the blades in another parabolic path to the middle of the turbine? Like that you will increase the force of the wind on the turbine dramatically? Hard to explain what I mean here, Something like an impeller?B
robert....why dont you isolate the system, use a rotor with similar size to the fan outlet and stick a pipe between the rotor and outlet, doing this will eliminate possibe error sources such as an unknown source of venturi effect pulling air from the sides
There's the cross sectional area, and then there is the effective cross sectional area. 😊
As the air is diverted by the turbine to an angle that is 90 degrees to the wind, the air has momentum and presents sort of like a wall that extends beyond the turbine's physical cross section, thus there builds up a slightly higher pressure zone in front and a lower pressure zone behind.
Storing 1.2 joules of energy and calculating 80% of the available energy. that's very impressive, but I suspect that maybe there is a significant margin of error. With these small numbers.
cheers mate
A few episodes ago you made a wind turbine concept for boats would this rotor possibly improve that device.
in calculation of the area of your wind capture device did you use total area? as I watched it I noticed that the blades have a flat cover the only effective capture area is inside too inside of the blades.
not meaning to disrespect
this is a great design 👌 cheers Robert
@Robert Murray-Smith is the video's number correct? You also refer to video 1921 3:12 , which I thought this was.
I can't tell if I'm simply misunderstanding something.
my bad - i linked tot he right video at the end of this video