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!
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.
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.
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. RU-vid 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.)
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
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.
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!
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.
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
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.
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.
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!
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 :)
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...
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.
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.
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.
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. 🙂
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'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.
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.
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).
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.
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
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 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.
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!
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…
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
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.
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.
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.
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.
@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.
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.
What I think you are doing is taking air from an area = A and ejecting it into area B Since area B is much larger than A it can accommodate it and not stop the flow. Remember that the air has to go somewhere after you remove the energy from it. Betz is more applicable to turbine blades.
I agree. From the Wikipedia article on Betz's Law: "If all of the energy coming from wind movement through a turbine were extracted as useful energy, the wind speed afterward would drop to zero. If the wind stopped moving at the exit of the turbine, then no more fresh wind could get in; it would be blocked. In order to keep the wind moving through the turbine, there has to be some wind movement, however small, on the other side with some wind speed greater than zero. Betz's law shows that as air flows through a certain area, and as wind speed slows from losing energy to extraction from a turbine, the airflow must distribute to a wider area. As a result, geometry limits any turbine efficiency to a maximum of 59.3%." Sounds like the calculation has to take into account a larger disk to account for the "exhaust" air. On the other hand, is that a practical issue? Probably means Rob has to keep his disk a certain distance from the ground, and from other disks/obstructions. Still implies he needs a smaller diameter than an equivalent bladed turbine.
@@user-gs6lp9ko1c There is another simple way to visualize it : if you were to have the most efficient angle to get energy of the air flow, it would be 90, more or less a wall, air being a fluid, it is easy to see that even that useless configuration cannot extract all power, since the more we are close to that wall the more the air pressure will raise, the air further from that will tend to go sideway i see it as a simple geometry issue. And obviously there is no configuration in which that does not happen.
Doesn't the Moment of inertia of the flywheel depend on the geometrical position of the masses. ie all in the centre or all at the perimeter. Could be wrong, it's been a while since I calculated that property on a flywheel.
It has to. It looks like the calculator he used is assuming an even distribution of mass. His flywheel is going to have way more energy than that with all the mass at the edges.
@@whatelseison8970 ... @2:42 shows the formula. If moment of inertia increases, the energy increases. This is just common sense broheim. Consider two spinning figure skaters with the same energy, one with their arms out and the other in, the one with their arms out is going to be spinning slower. IE his wheel doesn't have to spin as fast to have the same energy as a wheel that had equal weight distribution.
It's totally possible to get a reasonable 3d printer for under $200 (USD) now. If you tinker with this kind of thing a lot, it's well worth it, and with free files and inexpensive filament, you'll probably break even on costs buying kits of this sort of thing within 3 or 4 prints of moderate complexity.
It would be an interesting idea to extend the existing blades all the way to the center of the disk - in this way the wind will contact the blade more time, doing more work 🎉
@@rodmills4071 the drag shouldn't be the issue here, the point is to maximize the time of the wind contacting the curved blade and, hence, rotating the disk)
Does the mass used to calculate fly wheel energy include the shaft, rotating parts of the bearings, and the turbine itself? Maths adds up if the mean diameter is 125mm rather than the implied/started 150mm which I'm guessing is probably the OD. Mass distribution matters. Adding a load of foam to the OD would increase the OD but not meaningfully increase KE. Hence mean diameter is the diameter to centre of mass, not OD.
That rotor is more efficient than that three-bladed rotor it takes all the wind from the whole surface puts it all the way out to the points on the road or to push it and there's a million points around the edge of the rotor compared to the three on the other one so if it lost 48% and you got 98% that makes sense to me
I love these video, but the maths must be wrong here. The flywheel mass was predominantly the magnets on the outer rim, so the figure obtained on the website should have been the one representing a ring rather than a disk. ie closer to 2.4 joules than 1.2. That would mean over 100% efficency! Something doesn't add up somewhere. Keep up the great work!
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)
Well done Rob, I appreciate this increase in detail in the measurements. I do not have any difficulty in believing that you can beat the Betz limit, which seems to me a first-order number highly dependent on the details of the actual configuration. In order to see if your results are consistent, I would highly recommend taking a few other measurements, in particular at 5 and 20 secs, and if possible with a variable resistor to modulate the blower's airspeed. Also, doing an experiment with just a different rotor (simple three blades?) could help ascertain if the betz limit is something that depends on the aerodynamic details as I was speculating. Fascinating stuff!
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.
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
Notes: 1) you didn't calculate the true moment of inertia of the weird shape you got 2) what you measure is not the wind turbine efficiency. 3) to measure efficiency you need to compare the kinetic energy of the columb of air entering the surface area of your wind turbine and to compare it with the continues maximum energy output of the device. to measure that put a generator and control resistor value until you find maximum power. According to a very simple betz equation you will not get more that about 59% of the wind power. Your results maybe closer to 25%
I think a smoke test is first needed before you change the height of the blades. You may find you are losing potential extra energy from the wind not flowing through the blades but over the top as the wind flow may not be as thin as you think. Really nice idea though.
Has anyone taken this design and put some spirals from the top centre of the cone down to the perimiter to effectively add some more spin energy to the disc before it strikes the blades? Would be very interesting to see if even more energy could be extracted with that small addition.
