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Matt, The aerospace industry has been experimenting with "Open Rotor" designs for nearly 40 years now. The 20% fuel savings was known about in the 80's, but the noise and perception of passengers riding on a "propeller plane" instead of a "jet", along with fuel prices dropping prevented it from becoming mainstream. My dad has patents on some of this tech dating back to the late 80's and early 90's. en.wikipedia.org/wiki/Propfan
I had this idea over 20 years ago after hearing about a plane with toroidal wing, but got told that "if it was any good, someone more educated would have done it already." Thanks a lot, dad.
I'm surprised by the absence of mention of the one word most engineers dread "turbulence", the design seems quite genius dealing with the turbulence and the fluid dynamics that come with the wing tip vortices. Dealing with the turbulent flow and harnessing it is definitely more than 2 birds in 1 stone. It's the entire flock :P Definitely looking forward to the developments and applications. Thanks for the wonderful video covering topics like this as always.
And just imagine what we could achieve when we changed the traditional props on airplanes to these and changed those fan blades on turbofan jet engines to toroidial shapes. Now that would be interesting to see what sort of gains in power and fuel savings we would get there.
If a toroidal prop dissipates wing tip vortices, I wonder if the same design can be applied to a stationary prop; a wing? Maybe designing a stationary airfoil that incorporates such a design would improve flight capabilities of stationary wing aircraft?
@@ryanhungerford6448would the lower surface area of your new wing design also cut lift. Winglets already cut the leading edge vortices tip of most commercial passenger aircraft. It could definitely benefit current turboprop noise where these props already offer lower fuel consumption. Would it allow for a faster turboprop speed? I recall some speed limitations were due to leading edge tip damage as the local air nearby went supersonic
Nah, you do not need that- what you want to know is what will happen when you hit surface of the road, on your way down to a local lake...and how much $$ bills you will lose doing it.
@@untitled795 as a network engineer, I use principles in biomimicry 🦋 to optimimize networks and resources, to expedite fulfillment of requests, logistics 💫
All this talk about the toroidal propellers and async propellers just has me excited that there's still so much potential for improving known working designs. It leaves you wondering or imagining if such a simple change like this yields 20% improvements across the board for multiple mediums... what's left on the table we haven't thought up yet to improve.
There are plenty of things that fit that description. The trick is to get the efficiency to sync up with the cost and existing manufacturing facilites. E.g. there are plenty of hyper-efficient airliner designs, but they mostly require non-standard manufacture and novel materials, which makes them unappealing to companies who have to protect their bottom line.
@Paya So a bidet is what you are looking for, uses a small amount of water. You feel and are cleaner and you only need one small square of toilet paper to dry with. E Very efficient
It would be extremely naive to say "such a simple change like this". Because designing that kind of propeller requires a deep understanding of processes going on around spinning propeller, and these are quite complicated. Manufacturing of such a complex shape requires precision computer controlled machines. It is not something that could easily be made in a garage. So, we are producing propellers for almost two centuries, yet there is a room for improvement in that seemingly simple device.
For scenes where movement is important to illustrating something (i.e. I can't just pause the video and get enough information), like at 5:12 and 6:01, I would recommend making those clips longer (or putting them on a loop if they're short). I am repeatedly having to skip back, wait 7 seconds for the 3 second clip, try to see what is happening. I eventually just set playback speed really low on those parts, but it breaks up your narration and takes away from how well done everything else is.
The whole video is too fast to really take in most of the information. I get it that UA-camrs nowadays make their videos (incl. their voice recordings) a bit faster and usually I don't mind, but Ferrell overdoes it and his videos have become unwatchable to me on normal speed. It's a shame.
The reason people do that is so that you have to back the video up and re-watch the clip Again. UA-cam algorithm interprets that is a high-value engagement.
Edit: There actually might be something more to it... I can't say more so make of that what you will. I work for a marine propulsion engineering company. The props engineering team had a look into this and found the boosted efficiency claims to be wildly overstated, at least for the larger vessels we supply. As with most things, if it seems too good to be true, it usually is. They're a brilliant idea for drones though!
There's a boating channel on yt that tested the marine props. They seems to be tailor made to the specific engine setup. And the efficiency is mainly during half speed. Going full tilt removes any efficiency benefits and brings it on par with traditional props. But they have pretty fantastic stats when running them in their optimal conditions. Their price makes it somewhat infeasible right now however. How it fairs on huge ships are yet to be evaluated I think.
@@brucec954 They also have CPP systems (Controllable Pitch Propeller) so they can keep their shafts spinning in one direction regardless of forward or reverse.
@@KoRntech The 105% was specifically at that 4000 RPM range. This why they only account for about a 20% fuel efficiency increase. If you operate outside that range there is not as much difference. That is usually how sales graphs work, they only grab the best case scenario.
The conventional propeller shape also has a great benefit in its ability to allow for a mechanism to change the angle of attack of the blades. This is crucial for aircraft and some wind generators. It is a really interesting and challenging theme for engineers to develop an adaptable toroidal propeller.
Maybee it seems quite impossible at first, but to change the angle of attack, you can rotate the toroidal shape like a conventional propeller, at least to my understanding.
Turbulence=power loss. Same but different thought.. . Gasoline engines make a bunch of noise. Why are we not harnessing the energy that makes the loud pop. Obviously there's quite a bit of energy still coming out of the engine when the exhaust valves open. It just seems like technology would be better suited to harness this energy other than just a turbo to force the air back in.
I think variable props at best get around 75-80% more efficient over fixed props. But if there’s a baseline 200% more thrust and less turbulence of vortices (increasing overall lift with smoother air) is a easy upgrade as maintaining a fixed prop over a variable is drastic.
Those large ships you mention for the most part don't run on diesel (too expensive), they tend to run on bunker oil (cheap, energy-dense). They also tend to run at an engine rpm less than 400, which these props aren't designed for.
Turbulence/cavitation is still an issue in large ships and ducting the propellers would lead to significant energy savings. The problem with ducting propellers in ships is fowling and in drones, the extra mass is an issue. This propeller design avoids both those issues.
But engine rpm don't equal prop rpm which should be a lot more relevant for the prop design to be working or not, right? I'm no expert on boats or ships and would expect a cargo ship's prop to run slower than that of a boat but I can't make out why engine rpm should be a central argument
@@thilokm522 Actually in a big ship propeller rpm is probably the same as the engine rpm. However even propeller rpm is irrelevant, what is relevant is the speed of the tip of the propeller, which is a function of propeller rpm and propeller diameter. A big ship has a *much* larger propeller diameter, so the speed of the tip is still high enough that these sorts of propellers would be a significant improvement. If you can work out how to make them for large ships, then a 5% fuel saving means that next time the ship is in dry dock for maintenance if not before it is getting new propellers, even if they cost millions of dollars each.
@@jonathanbuzzard1376 More optimized prop shape is important, but a big issue with toroidal propellers in the open sea environment would be near continuous fowling with seaweed (not to mention other flotsam & jetsam). A fowled propeller vibrates violently and has significantly (40-70%) reduced efficiency. If a small inland or coastal boat prop gets fowled it is usually no big deal to stop & clear it-doing that with a huge freighter is another matter altogether. This is why self-clearing prop designs are such a big deal. (I should have added this to my original comment at the time I posted it.)
Some basic maths indicates that the tip speed of a 300mm diameter outboard engine at 4000 rpm is the same as that of a 10m diameter cargo ship prop doing 120 rpm
One relevant point that is getting little attention is that the benefits over traditional props are barely noticeable until the RPM's get relatively high (evidenced by the graph in this video). So instead of running these torroidal props at a high speed, the alternative is to run larger, traditional props at a slower speed, which most large commercial/military vessels do now. This will be a real game changer for drones and maybe light craft, but it will not reduce the carbon footprint of the shipping industry by half.
there's a limit to prop size that i think the shipping industry is already well aware of - ship draft. too big a prop would hit the bottom and break off. they really can't get any bigger safely.
My first thought when I see this propeller applied to marine applications is thats what those covered submarine props have looked like for years and militaries wanted to keep secret. Crazy how something that has been around for so long and utilized so much is still undergoing improvements to design.
Yeah they had classified the tech that let them not produce bubbles in the water and eliminate the churning sound they would make, I think it might be how long it takes civilian markets to figure it out on their own, but it is pretty shitty they prolly knew the whole time
Major Hardware did a couple episodes on the design. I am not a 3d modeler however I noticed that the drone propellers and all the PC fan designs did not have the depth that the boat prop had. A PC fan unlike a drone prop would need higher static pressure for efficiency as the weight is less of an issue compared to a drone application. More depth and less distance between the blades would greatly improve static pressure. It would be interesting to see someone create different designs between depth and possibly more blades to figure out the prop-er applications for this revolutionary concept. - @UndecidedMF I appreciate you letting this stew for a while to see what new comes up before making a video about it.
It would have been cool if this video included a quick reference to Major Hardware testing creative 3d printed designs based on user submissions. Even though it may not be drones or ships, their findings could foster other applications, like you noted this design was on a couple episodes. I like how he reports rpms, flow, sound, etc.
My physics game is weak, but in researching Sharrow (before I saw the price, more than my boat!) they made the point that in a ducted situation, the anti-cavitation and tip vortecise benifets reverse and are actually worse in most cases. They were testing for bow-thrusters. Probably not a magic bullet for Major Hardwares fan design test, but always cool to watch the tests
I have a micro quad copter that I have been tinkering with various 3D printed toroidal propeller designs. It has a one button takeoff and land function that uses lidar to detect its position off the ground. The higher efficiency propellers throw off the algorithm for this function to a point that rather than coming a meter off the ground and just staying there, it shoots up to 2-3 meters, drops down to half a meter, and fluctuates up and down several times before settling in at one meter.
You'll get the same benefit more cheaply by simply ducting your propellers. In general though, physical characteristics change with scale so the benefit difference probably won't be much on your micro quad.
It would make a more efficient blade no doubt. (I used to work on wind turbine blades) but the blades need to be actuated independently (optimize angle of attack during rotation). So this would be difficult, also the blades would require much more material. these blades are already massive(~13tons) , and non biodegradable (they just bury them) So I'm not sure the benefits would outweight the cost. no pun intended. I guess one could reduce the size of the blade to compensate for material and justify it by the increase in efficiency. But the engineering required to manufacture something that large, transport, and repair it. Seem unfeasible/un-Scaleable
What if they were used in Darwin-style turbines, the ones with the fans bladed laying flat midway up a tower that channels wind from the top down a tube. Consistent power, only one angle, air always flowing the same direction regardless of wind. I've been thinking on the feasibility of 'power chimneys' on top of large buildings, with their air output being funnelled into the building's A/C system, the power running basic services like lights and elevators.@@daizhanennals1485
@@daizhanennals1485 As for the angle of attack, some aircraft have a propeller where the pitch of the blades can be changed. I don't see why a wind turbine can't do the same thing.
all of these designs just remind me of the fluid dynamics explored by Viktor Schauberger. It's good to see it applied to a workable model. Also with the boat propeller, the major cost is with the fact that it's being machined from billet material, instead of being made from cast bronze. If it were cast, then it would be highly comparable to your average propeller as the volume of material isn't that much greater.
Excellent report. What is astounding is how a propeller's design is really at the heart of the pollution problem. What is second on the list is how to get more power from fuel combustion.
The thing you overlooked was that these propellers are indeed much more efficient, and as you showed especially at 3000-5000 rpm. Big container ships however do not have propellers operating at these speeds (because this is very inefficient!) and they run at about 100 rpm. So toroidal propellers probably don't help for this application. For drones, they are more quiet, but not more efficient.
@@webdactic For tri/quad+ type drones with fixed pitched props, they likely are more efficient. But he also showed drone airplanes, which are likely to provide little benefit. Specially with larger drones where variable pitched props are already common. For things like boats and tri/quad+ drones, which have a large RPM window, constantly speeding up and slowing down, especially with a large transition period (such a boat coming onto plane), benefits are likely to be found. For others, where variable pitched props are already common (wind turbines, most airplanes), benefits are likely to be significantly reduced or all but absent.
@@justanothercomment416 The MIT page on this states that it ""achieves thrust comparable to that of a multirotor drone propeller" not more. Probably because the efficiency loss of wingtip vortexes in air is significantly less than in water where cavitation is a huge problem. There is an inherent inefficiency with dirty air in the toroidal design and even at the high RPMs a drone operates at, it seems this is still slightly more than the gains from the reduced vortex drag.
The nice things about noisy drones is when you can zip a drone in and park it a couple of feet above your friends head before they realize what you are doing and then increase the prop speed to make it shoot straight up. Specially when you are far enough away that he can not catch up with you before he tires out and stops. Of course, that means you are going to have to be prepared and not get upset when he eventually does the same to you. Or he figures out a way to accurately drop water balloons on your head, in January, when it is 10 degrees. Lots of fun.
We looked Into this as well at our university. It seems most comparisons they Made were not with State of the art props en thus their efficiency gains are overestimated. Another slight issue is their inability for pitch control, limiting the use for windturbines and aircraft. Still a great video!
Finally, a satisfying video! You answered all of your initial questions from beginning to end. Both micro- and macro-applications were considered and the mechanical aspect was fairly visible. Thanks!
I wanna take my time out to appreciate the intro of Matt's videos. I have watched so many and have always felt this excitement for his content. The intro is so well written, always creates a hype which is followed by the perfect beat drop and music!! Appreciation and kudos to Matt and his team
so else was worried when, in that one episode, the music had been changed to a more upbeat version? Glad they reverted that decision - it's just the most perfect opening music of any UA-cam channel 😄👏
Hi Matt, I discovered this propeller a few months ago; I contacted someone I know in the electric boat industry; they told me they already knew about Sharrow, had tested it extensively and found no noticeable difference in efficiency; such a shame as electric boats need all the efficiency gains they can get due to battery range restrictions.
@@ernestdambach8925 it’s possible that the electric boat uses larger slower props due to electrics better torque at low speeds. ICE outboards basically use the water as a torque converter.
It might be that this toroidal prop is not going to make much of a difference for an electric powered boat on the basis that electric motors have very flat efficiency curves. If you consider an ICE the efficiency curve shows a dramatic reduction as you move from the peak torque (peak thermal efficiency) operating condition.
@@michaelharrison1093 Yes, that will have an impact however Sharrow also talks about the hydrodynamics which is separate from the engine/motor dynamics.
This is great, tnx for the info. It kinda sorta reminds me of the little winglets on the aircraft wings to reduce tip voratces. If you look at a jet landing in the rain you see the spirals coming off the wing tips.
This is fascinating! It might be interesting to see how this might work in combination with a Kort Nozzle in lower speed applications, as in towing vessels, how well it works in reverse, and the effects on vessel or aircraft maneuverability. I'd love to try one out! Propellers have come such a long way just in my lifetime, and I imagine there is a great deal more to learn. Many thanks!
What is fascinating is cavitation is actually from boiling water, yes the water boils due to the low pressure created from the boat prop. Love your videos!!
yes , by definition cavitation / boiling is when the pressure of the gas inside a liquid = atmospheric pressure above or around that liquid.... therefore if the propeller spins, it lowers the pressure inside the liquid to become more and more equal to the atmospheric pressure , then the bubbles pop. same physics in your kettle with heat doing the work, gas pressure in boiling water lowers to atmospheric pressure
I think the most fascinating part is that the water freezes after it boils! Maybe not behind a boat propeller, but just in laboratory conditions. (Vacuum chamber, etc.)
I like how they improved the propeller by splitting it in half making two propellers in one. They have done a similar thing with propeller engines for aircraft as well.
5 years ago, there were those new torrodial formed carbon high profile wheels for cycling. For the lowest aero drag possible. At that time, they were more stable, efficient and stiffer. But they didn't get a lot of media traction
*HAVING OWNED A YACHT* $5,000 is peanuts in boat money - I bought a box of 200 bronze screws [in 2002] - $600 New prop, prop shaft, cutlass bearing and coupling + costs of taking out of water, removal and refitting $6,000 [in 2002]
Yes but it’s even worse than that. That graph is smoke and mirrors for sure but according to this data the boat managed 64 kts (!) at 6000 rpm with the conventional prop. Yeah well, that didn’t happen because according to Worldcat specifications their boat does 45 knots flat out. In other words, the graph is a fiction, easily debunked. Another piece of BS here is that the so-called 3 blade Sharrow prop is actually a 6 blade. This alone significantly increases the advance ratio so comparing it with a 3 blade conventional prop is bogus.
Be interesting to see if the prop would make any difference in large cargo ships considering they only turn at a few hundred rpm. Based on the graph the smaller prop was good around cruising at 4000 rpm. But lower in the rpm it was barely more efficient.
Cargo ships run their props at slow speeds because that is where they are most efficient. If they could use this type of prop and be just as efficient at 10 times the RPM, they could cruise the seas at a much faster pace at the same MPH they get now.
Ships do have a much lower rpm, but they also have a much larger prop diameter, resulting in a similar tip speed when compared to stationary water. This tauroidal prop seems to gain efficiency based on tip speed, not rpm.
@@Shepshop1620, why not a smaller prop turning faster and generating the same thrust? Maybe a smaller power plant could be used? Nothing is going to push one of those monsters beyond its hull speed, of course. I would bet these would be fantastic for tug boats. How about those high speed hydrofoil ferry boats? Then there are the military applications... This is pretty big news, I think.
Not really, @@Wayoutthere. None of those, and particularly not more emissions. A new engine design seems fairly unlikely. Unless someone just wants to spend a lot of money rather than using something that is already available.
I would love to see this design in computer fans and graphics card fans and even PSU fans to help reduce their noise. Just imagine how much quieter your computers would be...
Would love to experience the boat propeller. that sound difference is crazy. Boats tend to be very inefficient due to all the drag. this propeller may pave the way to electric boats, where energy density has been a major concern
It's a six bladed propeller (three blades are swept forward, three are swept back, and they are joined where each set meet) that is being compared to a three bladed propeller that is horrifically overworked. The engine nearly needs to over-rev just to get the boat planing. If your boat isn't planing at 3000 rpm, something is horrifically wrong. Ask yourself, why did they need to compare their prop to a terribly overworked and so will appear hyper inefficient standard prop of half the displacement? Because they're trying to disguise the fact that they've designed a six bladed prop, which will itself be fairly inefficient for most modern small boats. Hell, even nuclear submarines that don't need to care about efficiency at all, just noise, only go up to seven, and usually five. More props means less efficiency, but they also mean lower loading per blade, which makes them feel and act like they're spinning than they really are. The lower loading means they cavitate at high RPM's, in this case high enough that the boat doesn't reach that limit. You can achieve the same with a conventional 6 bladed prop if you really want. You can also get a properly sized larger diameter three blade prop, or four if you really need it, to achieve the same lower loading without having to increase the blade count and cut efficiency. Again, very serious question, why is the company that is trying to justify you buying their 5K propeller only showing comparisons to what is blatantly an undersized prop? Why are they not comparing a cheap, inefficient, and badly designed three blade prop most engines come with? Why did they go out of their way to undersize the test prop so badly? Oh, because their prop doesn't create any savings or benefits when compared to a similar loaded and bladed prop, aside from being heavier and having higher form drag, which actually makes it slightly worse than a same sized six blade prop. Do the math if you don't believe me, or buy it and run it yourself.
*I HAD A MASSIVE ARGUMENT* on a car tuning channel that a whistling turbo was a BAD thing not a GOOD thing The whistling is vortex shedding at the tip of the blades - usually caused by a mismatch in the size of the turbo and the inlet X section - at best its literally ripping away the tips of the blades, at worst it is over boosting the system and can cause it to explode
Nice video, great implementation of this topic! Have you somehow come across approaches to use the toroidal concept for wind turbines? It would be exciting to develop a particularly quiet (small) wind turbine. Here, too, tip vorticies should be a cause of noise development! Due to the aerodynamics, however, the design would of course have to be different. An optimal fan is after all, as we all know, a catastrophic wind turbine system.
There are many solutions to tip noise, through designs that we already have, that wouldn't require a completely new prop design. Additionally, we look for a design that takes the least amount of material to produce. Weight and eol disposal are factors. The Toroidal design takes a lot more material. This rules it out for most real world applications.
The first time I ever saw a torodial windturbine was a horizontal desing back in the late 70's on a green energy exposition. As i remember correctly it was mostly too complex to scale up. One of the most remarkable things was the flexible desing let it change height and diameter when (wind)speed variated.
UA-cam absolutely blew up with videos of these toroidal propellers on drones a couple of months ago when the news broke out, and in reality, the results seemed to be quite underwhelming. You get a less annoying noise frequency range, sure, but most people experimenting with them found out they had significantly less thrust in some cases, negating efficiency or noise benefits, and while the noise did have a lower pitch, they're still very loud. The MIT videos were also quite disingenuous in the way they played with the volume: standard propellers were turned up significantly while the toroidal ones... weren't even playing any sound at all because Sebastian is talking over it, lol.
Typical propeller efficiency is 80%. Therefore when you see a caption claiming, quote, “105% efficiency boost” you should immediately realise it is bogus.
I wonder why it took so long. Since 2012 there was a PC Fan using that design. Probably no one thought about making anything more efficient just like in many other cases.
I am guessing that this is a prop suited for certain size vessels and is ideal to work in its specific field and application. If you work a prop that operates at an inefficent ratio for the majority of it's use, but that use is in the optimal performance for the toroidal prop, then it is likely best practice to use the toroidal prop in that application. Its not a one hat fits all situation, its a sun hat for a sunny day that you'd never wear in the rain
This design hasn't been used in vessels before in part because of the expense of making them, and the savings in fuel haven't been as urgent in the past. In the case of aircraft, it may be materials technology; composites and materials such as carbon fiber and aramids allow us to make shapes requiring higher strength to weight ratios than before. I'm looking forward to these being used on electric aircraft capable of carrying passengers and cargo.
I want one! But the up front cost is so high... My boat is a sailboat, so it's already pretty efficient, but it'd be great to cut the fuel cost for when I have to motor. (also those massive ships don't burn diesel, they run on "heavy fuel oil" which is closer to tar)
I saw some video about these propellers about a month ago. This is so cool. Industry has lots of money to invest in this kind of tech, which makes you wonder why this didn't happen sooner. I hope to see wide adoption of this propeller by many industries soon. Thank you.
I think it would be cool to see some applications within jet turbines, like maybe toroidal compressor blades at the first stage to suck in higher volumes of air for higher fuel efficiencies?
My first thought when I originally learned about these was if this sort of design would offer any benefits for something like the Mars drone... I'm curious how they would perform in a lower gravity, lower air pressure environment. And what kind of modifications would be necessary, if it is workable...
Question: Can this work for Computer fans too, or do those need different properties? These are so much quieter, it would be quite amazing for that setting, where you sit next to fans for potentially long times.
they have different properties. one of the main one is they arn't in an open air system, they need to push air hard through obstructions and such. also alot of the noise comes from the air inside and not just the fan but the turbulence of the air flow.
@@mryellow6918 part of what these toroidal fans seem to do is to reduce turbulence, at least the turbulence created right at the fan itself. I'd imagine that'd still be possible to do in the cooling fan setting?
@@Kram1032 what I mean is you can't do anything about the turbulence inside the case. And you can't control what's obstructing stuff. For example your gpu fan blowing in all directions even against case fans
There was a lot of questions to MIT experiments so i had tested 3d printed toroidal propellers on a drone - they was in fact louder and kind of shaky and unstable. It may work underwater with a rotating speed that required underwater, and without much turbulence. But as propeller for a drones - it it debatable, i believe they need more development to be productive.
I always marvel when I hear claims like, "drones consume 94% less energy per package than standard delivery vehicle." Really? Who has done that study? I am very skeptical about that number. 94% less? I would love for you to give a reference to that study since it seems very unlikely to me: a standard vehicle, in addition to our package, carries dozens of packages from other clients, while a drone only carries 1 package and must make the return trip without a payload. .
…the further I go through life, the more I realise it has always been full of claims like that, and people who accept them too easily. That was me when I was young.
Would these types of designs have any impact on fans and fan blades? It would be cool to see this possibly impact standard home box fans or even computer fans!
I didn't even think about electric fans and other cooling fans. It's probably gonna take a while for the design to be that commercially available though. (Also hopefully it still allows one to make funny noises in front of the fan xD)
Great content. I have subscribed to your channel for a while now, and I always find your production value high, and the quality of your content to be fantastic. I would gather that the cost of those propellers would have something to do with the precision needed to build them, as well as if there are any patents associated with their construction. But the whole technology sounds promising for many applications. Even wind turbines and other fluid dynamic applications. Thanks again as always. This also shows the possibilities of innovation and imagination. Those that shut it down seem to suffer from a lack of those aforementioned qualities. I suggest that looking at this topic with vision towards the future, and the possibilities it can explore and uncover.
there are vertical axis turbines that already use a similar shape and some dynamic kite based wind energy farms are also looking into such novel applications :)
I'd wager not, since: - bladed wind farms operate at _way_ lower RPMs where tip vortices are practically moot - the fluid dynamics work a little differently in reverse - likely invalidating any efficiencies that aren't just side effects of noise reduction - are _the propeller blades_ at wind farms even noisy, especially compared to the generators?
I would say yes and no. Windmill blades can now be adjusted for the best performance in different kinds of weather and i do not see how you could do that wit theas blades. That sead, because of the bigger range of affenciantie it might not have to.
Yes and no. The design should work the same for a wind turbine as it does for a propeller, but at those sizes increased material costs will make it unfeasible. It would likely also impact the efficiency of downwind turbines. The question is if the added material costs less than the profits you would gain with the added efficiency. You also need to figure out the engineering challenges that come with the added weight for the support structure and how that would affect possible height (which is corelated with higher wind speeds) and for the inertia of the system and how you would stop such wind turbine in dangerously high wind situation. My guess is that we could use this design with smaller home turbines
They could make the boat propellers much easier with lost wax casting instead of machining them from a solid block. most large props are bronze based anyway which is perfect for the lost wax method.
I've seen videos of large propellers being made; they still had to be machined at the end to get a good surface finish, then thoroughly examined. If the tips of a propeller can evaporate water, then imagine the forces that are experienced. Now imagine a hairline crack, or an imperfect casting where there is a 'cold shut', slag inclusions, or any other of the many possible defects from casting. At those speeds, the flying metal chunk would punch a hole through the boat or its occupants, and leave behind a dangerously unbalanced, fast-spinning prop shaft.
Funny that drone designers never took a que from fan designers for custom computers. For those of us who build our own, noise reduction is a key to a comfortable life behind a computer workstation. Thanks for doing a video on this topic.
I would guess that some of these designs have probably been tried before, but due to their geometry they can be very expensive to manufacture, so it probably didn't make too much sense.
At least 2, possibly 3 instances of similar developments have been brought to paper over the last century and a bit, at least one of them was patented. Unfortunately these designs never left the paper.
Love your videos but on this one, I think you overlooked that this shape of prop was not invented by MIT/Sharrow. Actually it s a really old patent from 1969 (patent no. US3504990A). It couldn't be efficently produced at time of invention, hence why its beeing revisited now now that cnc machining is cheap and 3D printing exists and the reason why it hasn't popped up sooner ;) Intresting non the less. Actually in the FPV drone world, some prop producers are already trying to make them, see kababfpv.
Very interesting! Perhaps 3-D computer modeling can tweak the designs for the greatest efficiency. It seems like anything with a fan or propeller could potentially benefit from this improvement. Maybe it can help as we transition away from fossil fuels.
Jet propulsion generally only offers increase in efficiency at higher speeds. You can see this clearly with aircraft. Planes design to cruise at speeds above 0.5 Mach almost always have jets, and below that have propellers. I’ve seen similar results with boats. I read an article about a boat that was offered with either a outdrive or a water jet. The water jet offered a small increase in top speed but the prop was more efficient at all other speeds. The conclusion of the article was that you’d only want the water jet if you had to operate in swallow water.
Large container ships have variable pitch propellers which increase efficiency at any given rpm vs. a fixed pitch. Same with constant speed propeller airplanes. The toroidal shape is only good for a fixed pitch since any change in blade angle would not be possible with the ends connecting.
00:37 "Why haven't we tried something like that sooner?" - Because the topic of sustainability never had been that relevant 30/40 years ago in comparison to now. We have never cared about our ressources in the past, because the majority had the mindset of "It will be enough in our lifetime" or "Planet Earth and its ressources are huge enough". The problem lies also in the very fast development in our technology and society by which we were not able to monitor such change in a healthy manner. For sure we already had concerns in the scientific area about our wasteful use of ressources 40 years ago, but those voices had been mostly ignored and were not strong enough, since we lived very good with what we had. Now in 2023 when it is almost already too late, we can feel the consequences of our actions and only now we are trying to optimize our behaviour. Unfortunately typical human behaviour if you ask me. Even though we are very late with those changes to support sustainability in different areas, I am somewhat hopeful that it will still be relevant for our future.
I’m a surf lifeguard In new zealand and we use 30hp Mercury outboards with 3.8m boats in large surf of up to 4.5+ m it would be awesome if / when they make them for smaller engines could allow less cavitation especially when going over large amounts of white water and allow less fuel to be used will be great to see the future
I came across this a couple/few months ago. A key advantage will be naval noise pollution as there's been a study or few on the affect of shipping noise on marine creatures and found it to be really quite harmful as, just like on land, creatures warn eachother with sound when predators are around, attract mates and other reasons, but prop noise interferers with this, contributing to the decline in marine life. I can imagine that this didn't become a thing previously because of the difficulty in production. As with [almost] all technological advancement, entire chains have to advance together to enable each other (or as misinformed ideologues would state ... "they didn't have Capitalism").
They wouldn't even get off the ground. This shape offers no way to change the pitch of the blade, which means the P-38 would need several miles of runway to get up to speed and a helicopter wouldn't be able to add collective to take off. Some things don't scale up.
Nice video, but maybe you could explain how you can have 105 % efficiency and not violate the law of conservation . And who uses propellers that are 20% efficient when the Wright brothers made 85% efficient ones.
The original units of this type from the beginning of engine power were 'screws' - that is air screws on heavy copter designs that never got off the ground and were laughed at, and screws that were on vessels in the water that produced excellent propulsion. This current Toroidal concept picks up where that left off, getting rid of the entire mass of the large screw and still using the efficiency of the physical design structure.
The noise and damage from cavitation is not caused by the bubble bursting. The noise and damage ocurrs when the bubble collapses back to liquid. The pressure pulse can be so high that it actually dimples the metal of the pump impeller.
Images drone delivery in New York City lol. Drone delivers is good for the countryside provided the drone has the range. And the suburbs arnt going to die tomorrow and will last for several generations. Neighborhoods that were built in the early to mid 1900s are standing today. So drone delivery will be needed for lowering energy requirements and lowering costs and removing the need of pizza delivery vehicles that are large crossovers and SUVs for delivering pizza.
I am fascinated by toroidal propeller technology and I brought it up and a Boat Drag Race at the Wild Horse Pass South of Phoenix. I spoke with racers and most had no clue what I was talking about. But, I ran across two guys that did know and had some unique input. The first was a big cargo ship captain. He said that the props that you use for thrust and that the toroidal props will be the future but it is NOT the best for speed. He said that boat speed is at the tip of the propeller so Drag Race Boats have a surprisingly small and not very broad blade. I got to talk to a long time boat drag racers and he kind of confirmed this and said that he used the toroidal prop does not work and he claimed that he tested in on his top fuel boats. He claimed the toroidal prop will not get the boat going from a dead stop to instantly high speed but in both cases boats are topped off at the same speed at the end. He also said that the drag race boat props are unique in that they have a very small pitch of about 6%.
Very exciting story! I hope you'll do an update when there are new developments in this area, such as commercial applications and cuts in production costs.
There’s still so much to discover in material science, geometric shapes and how they interact in given circumstances or in natural environment It’s amazing how such small word as physics can encompass Everything that exists or will exist even those that stopped exist but existed before,, how they act and react and influence and manipulate other materials changing it’s entire structure and properties
What do you think of Toroidal Propellers? Get an exclusive Surfshark deal! Enter promo code UNDECIDED for an extra 3 months free at surfshark.deals/undecided
If you liked this, check out Why Are Floating Wind Turbines So Huge? ua-cam.com/video/83FqqfODmmg/v-deo.html
Tedium of the constant injection of the "green" agenda misinformation forced into every video.
Toroidal shapes are found in nature, so it makes sense to make use of that blueprint.
I think they are good.
Matt,
The aerospace industry has been experimenting with "Open Rotor" designs for nearly 40 years now. The 20% fuel savings was known about in the 80's, but the noise and perception of passengers riding on a "propeller plane" instead of a "jet", along with fuel prices dropping prevented it from becoming mainstream.
My dad has patents on some of this tech dating back to the late 80's and early 90's. en.wikipedia.org/wiki/Propfan
I read about it some time ago. But PATENTS and this company can dictate the price, since no one else can make those.
I had this idea over 20 years ago after hearing about a plane with toroidal wing, but got told that "if it was any good, someone more educated would have done it already."
Thanks a lot, dad.
I understand that pain
To be fair, someone probably did do it already. Just because you're the first doesn't mean you'll get recognized for it.
That's not the mindset for any invention in human history...
Never, ever listen to someone who says things like that.
Yeah, that basically always means "that sounds hard and I'm too lazy" or "that sounds complicated and I'm not smart enough"
I'm surprised by the absence of mention of the one word most engineers dread "turbulence", the design seems quite genius dealing with the turbulence and the fluid dynamics that come with the wing tip vortices. Dealing with the turbulent flow and harnessing it is definitely more than 2 birds in 1 stone. It's the entire flock :P
Definitely looking forward to the developments and applications. Thanks for the wonderful video covering topics like this as always.
And just imagine what we could achieve when we changed the traditional props on airplanes to these and changed those fan blades on turbofan jet engines to toroidial shapes. Now that would be interesting to see what sort of gains in power and fuel savings we would get there.
@@MrBrander Since turbofans pump directly into the engine's bypass/cooling duct, the outcome would likely be net negative.
If a toroidal prop dissipates wing tip vortices, I wonder if the same design can be applied to a stationary prop; a wing?
Maybe designing a stationary airfoil that incorporates such a design would improve flight capabilities of stationary wing aircraft?
@@ryanhungerford6448would the lower surface area of your new wing design also cut lift. Winglets already cut the leading edge vortices tip of most commercial passenger aircraft. It could definitely benefit current turboprop noise where these props already offer lower fuel consumption. Would it allow for a faster turboprop speed? I recall some speed limitations were due to leading edge tip damage as the local air nearby went supersonic
Nah, you do not need that- what you want to know is what will happen when you hit surface of the road, on your way down to a local lake...and how much $$ bills you will lose doing it.
its fascinating that the more advanced machines get, the more biological they start to look
@@rossimartiWhile Evolutionary optimization is a mathematical optimization method.
the term is bio-mimicry
@@untitled795 as a network engineer, I use principles in biomimicry 🦋 to optimimize networks and resources, to expedite fulfillment of requests, logistics 💫
to be fair nature did have a 3.7 billion year headstart in doing trial and error
I feel like "biological look" is subjective.
All this talk about the toroidal propellers and async propellers just has me excited that there's still so much potential for improving known working designs. It leaves you wondering or imagining if such a simple change like this yields 20% improvements across the board for multiple mediums... what's left on the table we haven't thought up yet to improve.
There are plenty of things that fit that description. The trick is to get the efficiency to sync up with the cost and existing manufacturing facilites. E.g. there are plenty of hyper-efficient airliner designs, but they mostly require non-standard manufacture and novel materials, which makes them unappealing to companies who have to protect their bottom line.
toilet paper, for example. just paper on a roll. george costanza thinks it cannot be improved. i think he is wrong.
Steam freely rises - condense to liquid power generator as it travels down power hot plate heat water make steam
@Paya So a bidet is what you are looking for, uses a small amount of water. You feel and are cleaner and you only need one small square of toilet paper to dry with. E
Very efficient
It would be extremely naive to say "such a simple change like this".
Because designing that kind of propeller requires a deep understanding of processes going on around spinning propeller, and these are quite complicated.
Manufacturing of such a complex shape requires precision computer controlled machines. It is not something that could easily be made in a garage.
So, we are producing propellers for almost two centuries, yet there is a room for improvement in that seemingly simple device.
For scenes where movement is important to illustrating something (i.e. I can't just pause the video and get enough information), like at 5:12 and 6:01, I would recommend making those clips longer (or putting them on a loop if they're short). I am repeatedly having to skip back, wait 7 seconds for the 3 second clip, try to see what is happening. I eventually just set playback speed really low on those parts, but it breaks up your narration and takes away from how well done everything else is.
The whole video is too fast to really take in most of the information. I get it that UA-camrs nowadays make their videos (incl. their voice recordings) a bit faster and usually I don't mind, but Ferrell overdoes it and his videos have become unwatchable to me on normal speed. It's a shame.
The reason people do that is so that you have to back the video up and re-watch the clip Again. UA-cam algorithm interprets that is a high-value engagement.
Edit: There actually might be something more to it... I can't say more so make of that what you will.
I work for a marine propulsion engineering company. The props engineering team had a look into this and found the boosted efficiency claims to be wildly overstated, at least for the larger vessels we supply. As with most things, if it seems too good to be true, it usually is. They're a brilliant idea for drones though!
Maybe because large ships props run at lower RPM?
There's a boating channel on yt that tested the marine props. They seems to be tailor made to the specific engine setup. And the efficiency is mainly during half speed. Going full tilt removes any efficiency benefits and brings it on par with traditional props. But they have pretty fantastic stats when running them in their optimal conditions. Their price makes it somewhat infeasible right now however.
How it fairs on huge ships are yet to be evaluated I think.
@@brucec954 They also have CPP systems (Controllable Pitch Propeller) so they can keep their shafts spinning in one direction regardless of forward or reverse.
I had to imagine they were, 105%? If they claimed 15-30% it would seem more realistic
@@KoRntech The 105% was specifically at that 4000 RPM range. This why they only account for about a 20% fuel efficiency increase. If you operate outside that range there is not as much difference. That is usually how sales graphs work, they only grab the best case scenario.
The conventional propeller shape also has a great benefit in its ability to allow for a mechanism to change the angle of attack of the blades. This is crucial for aircraft and some wind generators. It is a really interesting and challenging theme for engineers to develop an adaptable toroidal propeller.
Maybee it seems quite impossible at first, but to change the angle of attack, you can rotate the toroidal shape like a conventional propeller, at least to my understanding.
Turbulence=power loss. Same but different thought.. . Gasoline engines make a bunch of noise. Why are we not harnessing the energy that makes the loud pop. Obviously there's quite a bit of energy still coming out of the engine when the exhaust valves open. It just seems like technology would be better suited to harness this energy other than just a turbo to force the air back in.
@@brian6739 In F1 they use this thing called MGU-H to make the turbo more efficient and to harness some of the lost energy, it's almost like magic.
@@brian6739 it's called a turbo
I think variable props at best get around 75-80% more efficient over fixed props. But if there’s a baseline 200% more thrust and less turbulence of vortices (increasing overall lift with smoother air) is a easy upgrade as maintaining a fixed prop over a variable is drastic.
Those large ships you mention for the most part don't run on diesel (too expensive), they tend to run on bunker oil (cheap, energy-dense). They also tend to run at an engine rpm less than 400, which these props aren't designed for.
Turbulence/cavitation is still an issue in large ships and ducting the propellers would lead to significant energy savings. The problem with ducting propellers in ships is fowling and in drones, the extra mass is an issue. This propeller design avoids both those issues.
But engine rpm don't equal prop rpm which should be a lot more relevant for the prop design to be working or not, right? I'm no expert on boats or ships and would expect a cargo ship's prop to run slower than that of a boat but I can't make out why engine rpm should be a central argument
@@thilokm522 Actually in a big ship propeller rpm is probably the same as the engine rpm. However even propeller rpm is irrelevant, what is relevant is the speed of the tip of the propeller, which is a function of propeller rpm and propeller diameter. A big ship has a *much* larger propeller diameter, so the speed of the tip is still high enough that these sorts of propellers would be a significant improvement. If you can work out how to make them for large ships, then a 5% fuel saving means that next time the ship is in dry dock for maintenance if not before it is getting new propellers, even if they cost millions of dollars each.
@@jonathanbuzzard1376 More optimized prop shape is important, but a big issue with toroidal propellers in the open sea environment would be near continuous fowling with seaweed (not to mention other flotsam & jetsam). A fowled propeller vibrates violently and has significantly (40-70%) reduced efficiency. If a small inland or coastal boat prop gets fowled it is usually no big deal to stop & clear it-doing that with a huge freighter is another matter altogether. This is why self-clearing prop designs are such a big deal. (I should have added this to my original comment at the time I posted it.)
Some basic maths indicates that the tip speed of a 300mm diameter outboard engine at 4000 rpm is the same as that of a 10m diameter cargo ship prop doing 120 rpm
One relevant point that is getting little attention is that the benefits over traditional props are barely noticeable until the RPM's get relatively high (evidenced by the graph in this video). So instead of running these torroidal props at a high speed, the alternative is to run larger, traditional props at a slower speed, which most large commercial/military vessels do now. This will be a real game changer for drones and maybe light craft, but it will not reduce the carbon footprint of the shipping industry by half.
Why not both? If these are better even at low speed but making propellers bigger is better, why not use these but big?
RPM and prop size matters, despite small rpm the tip of prop is really fast due to how massive props are on cargo ships.
there's a limit to prop size that i think the shipping industry is already well aware of - ship draft. too big a prop would hit the bottom and break off. they really can't get any bigger safely.
But if this design works for them they could transport faster without increasing energy use. Faster transport means more profit for shipping.
I remember reading that the engines in cargo ships have a redline of only a few hundred RPM.
My first thought when I see this propeller applied to marine applications is thats what those covered submarine props have looked like for years and militaries wanted to keep secret. Crazy how something that has been around for so long and utilized so much is still undergoing improvements to design.
Yeah they had classified the tech that let them not produce bubbles in the water and eliminate the churning sound they would make, I think it might be how long it takes civilian markets to figure it out on their own, but it is pretty shitty they prolly knew the whole time
unlikely. pictures of american props have leaked before and they were not toroidal. i'm pretty sure this is an entirely new technology.
"marinetime" lol
"Save two birds with one stone"
Very exciting to live today! So much to look forward to. I hope we all can live long enough to see the future
Major Hardware did a couple episodes on the design. I am not a 3d modeler however I noticed that the drone propellers and all the PC fan designs did not have the depth that the boat prop had. A PC fan unlike a drone prop would need higher static pressure for efficiency as the weight is less of an issue compared to a drone application. More depth and less distance between the blades would greatly improve static pressure. It would be interesting to see someone create different designs between depth and possibly more blades to figure out the prop-er applications for this revolutionary concept. - @UndecidedMF I appreciate you letting this stew for a while to see what new comes up before making a video about it.
It would have been cool if this video included a quick reference to Major Hardware testing creative 3d printed designs based on user submissions. Even though it may not be drones or ships, their findings could foster other applications, like you noted this design was on a couple episodes. I like how he reports rpms, flow, sound, etc.
My physics game is weak, but in researching Sharrow (before I saw the price, more than my boat!) they made the point that in a ducted situation, the anti-cavitation and tip vortecise benifets reverse and are actually worse in most cases. They were testing for bow-thrusters. Probably not a magic bullet for Major Hardwares fan design test, but always cool to watch the tests
As always Matt, your videos are informative and interesting at the same time.
You deserve props
Thanks! Glad you enjoyed it.
@Undecided with Matt Ferrell Did I just slide a propeller joke by you unnoticed?
And full of wishful thinking
@@jopo7996 power to the punsters!
This has applications in many systems that propel things through fluids (air and liquids) and move the fluids themselves.
Thanks!
Thank you Laura!
Thanks!
Thank you!
I have a micro quad copter that I have been tinkering with various 3D printed toroidal propeller designs. It has a one button takeoff and land function that uses lidar to detect its position off the ground. The higher efficiency propellers throw off the algorithm for this function to a point that rather than coming a meter off the ground and just staying there, it shoots up to 2-3 meters, drops down to half a meter, and fluctuates up and down several times before settling in at one meter.
You'll get the same benefit more cheaply by simply ducting your propellers. In general though, physical characteristics change with scale so the benefit difference probably won't be much on your micro quad.
I've wondered how efficient this propeller design would be in a wind turbine.
It would make a more efficient blade no doubt.
(I used to work on wind turbine blades)
but the blades need to be actuated independently (optimize angle of attack during rotation). So this would be difficult, also the blades would require much more material. these blades are already massive(~13tons) , and non biodegradable (they just bury them) So I'm not sure the benefits would outweight the cost. no pun intended.
I guess one could reduce the size of the blade to compensate for material and justify it by the increase in efficiency. But the engineering required to manufacture something that large, transport, and repair it. Seem unfeasible/un-Scaleable
What if they were used in Darwin-style turbines, the ones with the fans bladed laying flat midway up a tower that channels wind from the top down a tube. Consistent power, only one angle, air always flowing the same direction regardless of wind. I've been thinking on the feasibility of 'power chimneys' on top of large buildings, with their air output being funnelled into the building's A/C system, the power running basic services like lights and elevators.@@daizhanennals1485
@@daizhanennals1485 As for the angle of attack, some aircraft have a propeller where the pitch of the blades can be changed. I don't see why a wind turbine can't do the same thing.
@@twistedyogert All wind turbines can adjust the angle of attack..
Wind turbine blades are already enormous. It would be impossible to make the blades like that.
all of these designs just remind me of the fluid dynamics explored by Viktor Schauberger. It's good to see it applied to a workable model. Also with the boat propeller, the major cost is with the fact that it's being machined from billet material, instead of being made from cast bronze. If it were cast, then it would be highly comparable to your average propeller as the volume of material isn't that much greater.
Díky!
Thank you!
Excellent report. What is astounding is how a propeller's design is really at the heart of the pollution problem. What is second on the list is how to get more power from fuel combustion.
The thing you overlooked was that these propellers are indeed much more efficient, and as you showed especially at 3000-5000 rpm. Big container ships however do not have propellers operating at these speeds (because this is very inefficient!) and they run at about 100 rpm. So toroidal propellers probably don't help for this application. For drones, they are more quiet, but not more efficient.
Completely correct. Most of the information provided in the video is extremely inaccurate and misleading.
Why are they not more efficient for drones?
@@webdactic I think it has to be optimised for drones. It's hard to say
@@webdactic For tri/quad+ type drones with fixed pitched props, they likely are more efficient. But he also showed drone airplanes, which are likely to provide little benefit. Specially with larger drones where variable pitched props are already common. For things like boats and tri/quad+ drones, which have a large RPM window, constantly speeding up and slowing down, especially with a large transition period (such a boat coming onto plane), benefits are likely to be found. For others, where variable pitched props are already common (wind turbines, most airplanes), benefits are likely to be significantly reduced or all but absent.
@@justanothercomment416 The MIT page on this states that it ""achieves thrust comparable to that of a multirotor drone propeller" not more. Probably because the efficiency loss of wingtip vortexes in air is significantly less than in water where cavitation is a huge problem. There is an inherent inefficiency with dirty air in the toroidal design and even at the high RPMs a drone operates at, it seems this is still slightly more than the gains from the reduced vortex drag.
The nice things about noisy drones is when you can zip a drone in and park it a couple of feet above your friends head before they realize what you are doing and then increase the prop speed to make it shoot straight up.
Specially when you are far enough away that he can not catch up with you before he tires out and stops. Of course, that means you are going to have to be prepared and not get upset when he eventually does the same to you. Or he figures out a way to accurately drop water balloons on your head, in January, when it is 10 degrees.
Lots of fun.
We looked Into this as well at our university. It seems most comparisons they Made were not with State of the art props en thus their efficiency gains are overestimated. Another slight issue is their inability for pitch control, limiting the use for windturbines and aircraft. Still a great video!
Just having less noise would be enough for some applications
Matt is just is a "NEATO" cheerleader ----he cries Go ,STUFFF! yea! now where are my blind followers, click- like my prettieszzz
I didn't need to look at it, "105%" efficiency told me everything I need to know.
Finally, a satisfying video! You answered all of your initial questions from beginning to end. Both micro- and macro-applications were considered and the mechanical aspect was fairly visible. Thanks!
8:17 "Surely someone must have been out there experimenting with non standard propeller shapes."
Militaries with modern submarines: *Nervous sweating*
I wanna take my time out to appreciate the intro of Matt's videos. I have watched so many and have always felt this excitement for his content. The intro is so well written, always creates a hype which is followed by the perfect beat drop and music!! Appreciation and kudos to Matt and his team
WTF?
Slurp
so else was worried when, in that one episode, the music had been changed to a more upbeat version? Glad they reverted that decision - it's just the most perfect opening music of any UA-cam channel 😄👏
Hi Matt, I discovered this propeller a few months ago; I contacted someone I know in the electric boat industry; they told me they already knew about Sharrow, had tested it extensively and found no noticeable difference in efficiency; such a shame as electric boats need all the efficiency gains they can get due to battery range restrictions.
Sounds like your friend needs to improve their testing methods.
Maybe they work best in sharrow water.
@@ernestdambach8925 it’s possible that the electric boat uses larger slower props due to electrics better torque at low speeds. ICE outboards basically use the water as a torque converter.
It might be that this toroidal prop is not going to make much of a difference for an electric powered boat on the basis that electric motors have very flat efficiency curves. If you consider an ICE the efficiency curve shows a dramatic reduction as you move from the peak torque (peak thermal efficiency) operating condition.
@@michaelharrison1093 Yes, that will have an impact however Sharrow also talks about the hydrodynamics which is separate from the engine/motor dynamics.
This is great, tnx for the info. It kinda sorta reminds me of the little winglets on the aircraft wings to reduce tip voratces. If you look at a jet landing in the rain you see the spirals coming off the wing tips.
This is fascinating! It might be interesting to see how this might work in combination with a Kort Nozzle in lower speed applications, as in towing vessels, how well it works in reverse, and the effects on vessel or aircraft maneuverability. I'd love to try one out! Propellers have come such a long way just in my lifetime, and I imagine there is a great deal more to learn. Many thanks!
I’d like to see some more independent real world testing on these. Seems like everybody is buying the efficiency gains without much skepticism
What is fascinating is cavitation is actually from boiling water, yes the water boils due to the low pressure created from the boat prop. Love your videos!!
yes , by definition cavitation / boiling is when the pressure of the gas inside a liquid = atmospheric pressure above or around that liquid.... therefore if the propeller spins, it lowers the pressure inside the liquid to become more and more equal to the atmospheric pressure , then the bubbles pop. same physics in your kettle with heat doing the work, gas pressure in boiling water lowers to atmospheric pressure
I think the most fascinating part is that the water freezes after it boils! Maybe not behind a boat propeller, but just in laboratory conditions. (Vacuum chamber, etc.)
I like how they improved the propeller by splitting it in half making two propellers in one. They have done a similar thing with propeller engines for aircraft as well.
5 years ago, there were those new torrodial formed carbon high profile wheels for cycling. For the lowest aero drag possible. At that time, they were more stable, efficient and stiffer. But they didn't get a lot of media traction
*HAVING OWNED A YACHT* $5,000 is peanuts in boat money - I bought a box of 200 bronze screws [in 2002] - $600
New prop, prop shaft, cutlass bearing and coupling + costs of taking out of water, removal and refitting $6,000 [in 2002]
7:46 'How to lie with statistics'
Graph starts at 5 instead of zero which skews perception for those who didn't notice this
Yes but it’s even worse than that. That graph is smoke and mirrors for sure but according to this data the boat managed 64 kts (!) at 6000 rpm with the conventional prop. Yeah well, that didn’t happen because according to Worldcat specifications their boat does 45 knots flat out. In other words, the graph is a fiction, easily debunked.
Another piece of BS here is that the so-called 3 blade Sharrow prop is actually a 6 blade. This alone significantly increases the advance ratio so comparing it with a 3 blade conventional prop is bogus.
Be interesting to see if the prop would make any difference in large cargo ships considering they only turn at a few hundred rpm. Based on the graph the smaller prop was good around cruising at 4000 rpm. But lower in the rpm it was barely more efficient.
Cargo ships run their props at slow speeds because that is where they are most efficient. If they could use this type of prop and be just as efficient at 10 times the RPM, they could cruise the seas at a much faster pace at the same MPH they get now.
Ships do have a much lower rpm, but they also have a much larger prop diameter, resulting in a similar tip speed when compared to stationary water. This tauroidal prop seems to gain efficiency based on tip speed, not rpm.
@@Shepshop1620, why not a smaller prop turning faster and generating the same thrust? Maybe a smaller power plant could be used?
Nothing is going to push one of those monsters beyond its hull speed, of course.
I would bet these would be fantastic for tug boats.
How about those high speed hydrofoil ferry boats?
Then there are the military applications...
This is pretty big news, I think.
@@MyName-tb9oz Faster rpm means much more wear and tear , needing to design entirely new engines and more emissions.
Not really, @@Wayoutthere. None of those, and particularly not more emissions. A new engine design seems fairly unlikely. Unless someone just wants to spend a lot of money rather than using something that is already available.
I would love to see this design in computer fans and graphics card fans and even PSU fans to help reduce their noise. Just imagine how much quieter your computers would be...
Would love to experience the boat propeller. that sound difference is crazy. Boats tend to be very inefficient due to all the drag. this propeller may pave the way to electric boats, where energy density has been a major concern
It's a six bladed propeller (three blades are swept forward, three are swept back, and they are joined where each set meet) that is being compared to a three bladed propeller that is horrifically overworked. The engine nearly needs to over-rev just to get the boat planing. If your boat isn't planing at 3000 rpm, something is horrifically wrong.
Ask yourself, why did they need to compare their prop to a terribly overworked and so will appear hyper inefficient standard prop of half the displacement? Because they're trying to disguise the fact that they've designed a six bladed prop, which will itself be fairly inefficient for most modern small boats. Hell, even nuclear submarines that don't need to care about efficiency at all, just noise, only go up to seven, and usually five.
More props means less efficiency, but they also mean lower loading per blade, which makes them feel and act like they're spinning than they really are. The lower loading means they cavitate at high RPM's, in this case high enough that the boat doesn't reach that limit. You can achieve the same with a conventional 6 bladed prop if you really want. You can also get a properly sized larger diameter three blade prop, or four if you really need it, to achieve the same lower loading without having to increase the blade count and cut efficiency.
Again, very serious question, why is the company that is trying to justify you buying their 5K propeller only showing comparisons to what is blatantly an undersized prop? Why are they not comparing a cheap, inefficient, and badly designed three blade prop most engines come with? Why did they go out of their way to undersize the test prop so badly?
Oh, because their prop doesn't create any savings or benefits when compared to a similar loaded and bladed prop, aside from being heavier and having higher form drag, which actually makes it slightly worse than a same sized six blade prop.
Do the math if you don't believe me, or buy it and run it yourself.
Amazing innovation that will go a long way across many sectors and Matt put it across with gusto. Nice
*I HAD A MASSIVE ARGUMENT* on a car tuning channel that a whistling turbo was a BAD thing not a GOOD thing
The whistling is vortex shedding at the tip of the blades - usually caused by a mismatch in the size of the turbo and the inlet X section - at best its literally ripping away the tips of the blades, at worst it is over boosting the system and can cause it to explode
Nice video, great implementation of this topic!
Have you somehow come across approaches to use the toroidal concept for wind turbines? It would be exciting to develop a particularly quiet (small) wind turbine. Here, too, tip vorticies should be a cause of noise development!
Due to the aerodynamics, however, the design would of course have to be different. An optimal fan is after all, as we all know, a catastrophic wind turbine system.
There are many solutions to tip noise, through designs that we already have, that wouldn't require a completely new prop design.
Additionally, we look for a design that takes the least amount of material to produce. Weight and eol disposal are factors.
The Toroidal design takes a lot more material. This rules it out for most real world applications.
The first time I ever saw a torodial windturbine was a horizontal desing back in the late 70's on a green energy exposition. As i remember correctly it was mostly too complex to scale up. One of the most remarkable things was the flexible desing let it change height and diameter when (wind)speed variated.
You had me at "donut shape". I knew I liked donuts for a good reason. D-OH.
UA-cam absolutely blew up with videos of these toroidal propellers on drones a couple of months ago when the news broke out, and in reality, the results seemed to be quite underwhelming. You get a less annoying noise frequency range, sure, but most people experimenting with them found out they had significantly less thrust in some cases, negating efficiency or noise benefits, and while the noise did have a lower pitch, they're still very loud. The MIT videos were also quite disingenuous in the way they played with the volume: standard propellers were turned up significantly while the toroidal ones... weren't even playing any sound at all because Sebastian is talking over it, lol.
That was due to the quality of their models vs the MIT variants.
A true refined one is much more efficient.
Typical propeller efficiency is 80%. Therefore when you see a caption claiming, quote, “105% efficiency boost” you should immediately realise it is bogus.
I wonder why it took so long. Since 2012 there was a PC Fan using that design. Probably no one thought about making anything more efficient just like in many other cases.
I am guessing that this is a prop suited for certain size vessels and is ideal to work in its specific field and application. If you work a prop that operates at an inefficent ratio for the majority of it's use, but that use is in the optimal performance for the toroidal prop, then it is likely best practice to use the toroidal prop in that application. Its not a one hat fits all situation, its a sun hat for a sunny day that you'd never wear in the rain
This design hasn't been used in vessels before in part because of the expense of making them, and the savings in fuel haven't been as urgent in the past. In the case of aircraft, it may be materials technology; composites and materials such as carbon fiber and aramids allow us to make shapes requiring higher strength to weight ratios than before. I'm looking forward to these being used on electric aircraft capable of carrying passengers and cargo.
Electric plane? We aren't even close. 😂
The future of aviation are ornithopters not propellers
I find the beep a vehicle makes when backing up the most annoying sound on earth.
I want one! But the up front cost is so high... My boat is a sailboat, so it's already pretty efficient, but it'd be great to cut the fuel cost for when I have to motor. (also those massive ships don't burn diesel, they run on "heavy fuel oil" which is closer to tar)
I saw some video about these propellers about a month ago. This is so cool. Industry has lots of money to invest in this kind of tech, which makes you wonder why this didn't happen sooner. I hope to see wide adoption of this propeller by many industries soon. Thank you.
I think it would be cool to see some applications within jet turbines, like maybe toroidal compressor blades at the first stage to suck in higher volumes of air for higher fuel efficiencies?
Turbines don't have the same problems with tip turbulence. The blades run very close to the body of the compressor.
My first thought when I originally learned about these was if this sort of design would offer any benefits for something like the Mars drone... I'm curious how they would perform in a lower gravity, lower air pressure environment. And what kind of modifications would be necessary, if it is workable...
Question: Can this work for Computer fans too, or do those need different properties? These are so much quieter, it would be quite amazing for that setting, where you sit next to fans for potentially long times.
they have different properties. one of the main one is they arn't in an open air system, they need to push air hard through obstructions and such. also alot of the noise comes from the air inside and not just the fan but the turbulence of the air flow.
ps, you can get quiet fans.
@@mryellow6918 part of what these toroidal fans seem to do is to reduce turbulence, at least the turbulence created right at the fan itself. I'd imagine that'd still be possible to do in the cooling fan setting?
@@Kram1032 what I mean is you can't do anything about the turbulence inside the case. And you can't control what's obstructing stuff. For example your gpu fan blowing in all directions even against case fans
@@mryellow6918 certainly, but I guess I'm not sure that that's enough to dismiss the sound of turbulence happening at the fan blades.
There was a lot of questions to MIT experiments so i had tested 3d printed toroidal propellers on a drone - they was in fact louder and kind of shaky and unstable. It may work underwater with a rotating speed that required underwater, and without much turbulence. But as propeller for a drones - it it debatable, i believe they need more development to be productive.
I always marvel when I hear claims like, "drones consume 94% less energy per package than standard delivery vehicle." Really? Who has done that study? I am very skeptical about that number. 94% less? I would love for you to give a reference to that study since it seems very unlikely to me: a standard vehicle, in addition to our package, carries dozens of packages from other clients, while a drone only carries 1 package and must make the return trip without a payload. .
…the further I go through life, the more I realise it has always been full of claims like that, and people who accept them too easily. That was me when I was young.
Would these types of designs have any impact on fans and fan blades? It would be cool to see this possibly impact standard home box fans or even computer fans!
I didn't even think about electric fans and other cooling fans. It's probably gonna take a while for the design to be that commercially available though. (Also hopefully it still allows one to make funny noises in front of the fan xD)
*_Props_* to Toroidal for trying to improve part of the world.
sorry bro thats a dislike
Great content. I have subscribed to your channel for a while now, and I always find your production value high, and the quality of your content to be fantastic. I would gather that the cost of those propellers would have something to do with the precision needed to build them, as well as if there are any patents associated with their construction. But the whole technology sounds promising for many applications. Even wind turbines and other fluid dynamic applications. Thanks again as always.
This also shows the possibilities of innovation and imagination. Those that shut it down seem to suffer from a lack of those aforementioned qualities. I suggest that looking at this topic with vision towards the future, and the possibilities it can explore and uncover.
Thanks Matt, i finally understood cavitation.
Great show, thanks Matt!
Hi Matt,
would these propellers work for wind farms? A similar improvement in efficiency / reduction in noise would be fantastic.
there are vertical axis turbines that already use a similar shape and some dynamic kite based wind energy farms are also looking into such novel applications :)
I'd wager not, since:
- bladed wind farms operate at _way_ lower RPMs where tip vortices are practically moot
- the fluid dynamics work a little differently in reverse - likely invalidating any efficiencies that aren't just side effects of noise reduction
- are _the propeller blades_ at wind farms even noisy, especially compared to the generators?
I would say yes and no. Windmill blades can now be adjusted for the best performance in different kinds of weather and i do not see how you could do that wit theas blades. That sead, because of the bigger range of affenciantie it might not have to.
Yes and no. The design should work the same for a wind turbine as it does for a propeller, but at those sizes increased material costs will make it unfeasible. It would likely also impact the efficiency of downwind turbines. The question is if the added material costs less than the profits you would gain with the added efficiency. You also need to figure out the engineering challenges that come with the added weight for the support structure and how that would affect possible height (which is corelated with higher wind speeds) and for the inertia of the system and how you would stop such wind turbine in dangerously high wind situation. My guess is that we could use this design with smaller home turbines
They could make the boat propellers much easier with lost wax casting instead of machining them from a solid block. most large props are bronze based anyway which is perfect for the lost wax method.
The imperfections would make the propeller useless. Any surface imperfections add cavitation and cause degradation over time.
I've seen videos of large propellers being made; they still had to be machined at the end to get a good surface finish, then thoroughly examined. If the tips of a propeller can evaporate water, then imagine the forces that are experienced. Now imagine a hairline crack, or an imperfect casting where there is a 'cold shut', slag inclusions, or any other of the many possible defects from casting.
At those speeds, the flying metal chunk would punch a hole through the boat or its occupants, and leave behind a dangerously unbalanced, fast-spinning prop shaft.
Funny that drone designers never took a que from fan designers for custom computers.
For those of us who build our own, noise reduction is a key to a comfortable life behind a computer workstation.
Thanks for doing a video on this topic.
Those fans are usually spinning much much slower.
This video popped up in my feed, glad I watched it. This stuff is exciting
Thanks for all that information which is so useful and I appreciate and admire this channel
But did really no-one think of this before? or is it true that it only got developed because of modern tools? (simulations, 3d printing, what else?)
I would guess that some of these designs have probably been tried before, but due to their geometry they can be very expensive to manufacture, so it probably didn't make too much sense.
@@Anfros. yeah that's what I mean, because of modern tools, manufacture got cheaper, iteration got faster, planning&measurement more efficient..
At least 2, possibly 3 instances of similar developments have been brought to paper over the last century and a bit, at least one of them was patented. Unfortunately these designs never left the paper.
Probably get applied to windmills too, particularly the more consumer versions meant for rooftops and yards
I can't help but think about Morbo.
Love your videos but on this one, I think you overlooked that this shape of prop was not invented by MIT/Sharrow. Actually it s a really old patent from 1969 (patent no. US3504990A). It couldn't be efficently produced at time of invention, hence why its beeing revisited now now that cnc machining is cheap and 3D printing exists and the reason why it hasn't popped up sooner ;) Intresting non the less. Actually in the FPV drone world, some prop producers are already trying to make them, see kababfpv.
I watched a few videos on this subject, and it is amazing the savings that can be made!
Do they teach a course on dragging things out to occupy more attention time?
To be fair, it is a very propelling argument...I mean compelling
😂
As an aerospace engineer to be, I do worry how this new design can affect jet engines.
Or ducted fan.
Very interesting! Perhaps 3-D computer modeling can tweak the designs for the greatest efficiency. It seems like anything with a fan or propeller could potentially benefit from this improvement. Maybe it can help as we transition away from fossil fuels.
I’m certain the navy already come up with similarly designed propellers for submarines
+1.. Always the very best ... Very informative! .. Who needs a boat? .. Cheers, Vail, Colorado
I'm curious how this performs compared to water jet propulsion.
Pump-jets are efficient and don’t suffer as much from cavitation because they run at higher pressure. Would be interesting to see how they compare.
Jet propulsion generally only offers increase in efficiency at higher speeds. You can see this clearly with aircraft. Planes design to cruise at speeds above 0.5 Mach almost always have jets, and below that have propellers. I’ve seen similar results with boats. I read an article about a boat that was offered with either a outdrive or a water jet. The water jet offered a small increase in top speed but the prop was more efficient at all other speeds. The conclusion of the article was that you’d only want the water jet if you had to operate in swallow water.
Large container ships have variable pitch propellers which increase efficiency at any given rpm vs. a fixed pitch. Same with constant speed propeller airplanes. The toroidal shape is only good for a fixed pitch since any change in blade angle would not be possible with the ends connecting.
Knew there had to be a catch.
Come to think of it, though, at least in terms of cargo ships, isn't it fine if they run at the same, low speed most of the time?
@@asahearts1 Always a catch. Just like advertisements that are too good to be true and every UA-cam is advertising it.
00:37 "Why haven't we tried something like that sooner?" - Because the topic of sustainability never had been that relevant 30/40 years ago in comparison to now. We have never cared about our ressources in the past, because the majority had the mindset of "It will be enough in our lifetime" or "Planet Earth and its ressources are huge enough". The problem lies also in the very fast development in our technology and society by which we were not able to monitor such change in a healthy manner. For sure we already had concerns in the scientific area about our wasteful use of ressources 40 years ago, but those voices had been mostly ignored and were not strong enough, since we lived very good with what we had. Now in 2023 when it is almost already too late, we can feel the consequences of our actions and only now we are trying to optimize our behaviour. Unfortunately typical human behaviour if you ask me. Even though we are very late with those changes to support sustainability in different areas, I am somewhat hopeful that it will still be relevant for our future.
I’m a surf lifeguard In new zealand and we use 30hp Mercury outboards with 3.8m boats in large surf of up to 4.5+ m it would be awesome if / when they make them for smaller engines could allow less cavitation especially when going over large amounts of white water and allow less fuel to be used will be great to see the future
I work for Kongsberg, and I hadn't heard of that scandal😲. Reading up on it now. Thanks for a great video 😀.
I came across this a couple/few months ago. A key advantage will be naval noise pollution as there's been a study or few on the affect of shipping noise on marine creatures and found it to be really quite harmful as, just like on land, creatures warn eachother with sound when predators are around, attract mates and other reasons, but prop noise interferers with this, contributing to the decline in marine life.
I can imagine that this didn't become a thing previously because of the difficulty in production. As with [almost] all technological advancement, entire chains have to advance together to enable each other (or as misinformed ideologues would state ... "they didn't have Capitalism").
If it can successfully be scaled up, I’d love to see if it can make the stealthiest helicopter rotor or even be retrofitted to the Osprey 🧐🧐
The Osprey has some of the most efficient props ever designed, over 90% at medium load.
I'd love to see how, say, a P-38 Lightning could perform with props like these. Or a helicopter like the Comanche.
They wouldn't even get off the ground. This shape offers no way to change the pitch of the blade, which means the P-38 would need several miles of runway to get up to speed and a helicopter wouldn't be able to add collective to take off. Some things don't scale up.
I like the sound of drones, especially fast quads zooming around.
Great video, Matt.
I liked it.
Thank you
Nice video, but maybe you could explain how you can have 105 % efficiency and not violate the law of conservation . And who uses propellers that are 20% efficient when the Wright brothers made 85% efficient ones.
Great topic! Thanks for updating us and sharing.
All the best.
Could wind turbine get this tech? Or would make electricity production lower?
Nice video on its history and potential- have heard of them over the last year, but no real details. Thanks for filling the gap.
Thank you for making your videos. They are addictive.
The original units of this type from the beginning of engine power were 'screws' - that is air screws on heavy copter designs that never got off the ground and were laughed at, and screws that were on vessels in the water that produced excellent propulsion.
This current Toroidal concept picks up where that left off, getting rid of the entire mass of the large screw and still using the efficiency of the physical design structure.
Great video, thank you for making it.
I remember in 1970 I saw the same type of boat propeller used in Ocean City Maryland. This is not new but a cool idea Matt. Nive video.
unloading the wing tips also
is very beneficial in reducing the drag of wings and propellers
The noise and damage from cavitation is not caused by the bubble bursting. The noise and damage ocurrs when the bubble collapses back to liquid. The pressure pulse can be so high that it actually dimples the metal of the pump impeller.
yea, drone delivery is not a net negative from centralized grocery stores and walking to them. like so many problems specific to suburbanization....
Images drone delivery in New York City lol.
Drone delivers is good for the countryside provided the drone has the range. And the suburbs arnt going to die tomorrow and will last for several generations. Neighborhoods that were built in the early to mid 1900s are standing today. So drone delivery will be needed for lowering energy requirements and lowering costs and removing the need of pizza delivery vehicles that are large crossovers and SUVs for delivering pizza.
I am fascinated by toroidal propeller technology and I brought it up and a Boat Drag Race at the Wild Horse Pass South of Phoenix. I spoke with racers and most had no clue what I was talking about. But, I ran across two guys that did know and had some unique input. The first was a big cargo ship captain. He said that the props that you use for thrust and that the toroidal props will be the future but it is NOT the best for speed. He said that boat speed is at the tip of the propeller so Drag Race Boats have a surprisingly small and not very broad blade. I got to talk to a long time boat drag racers and he kind of confirmed this and said that he used the toroidal prop does not work and he claimed that he tested in on his top fuel boats. He claimed the toroidal prop will not get the boat going from a dead stop to instantly high speed but in both cases boats are topped off at the same speed at the end. He also said that the drag race boat props are unique in that they have a very small pitch of about 6%.
Very exciting story! I hope you'll do an update when there are new developments in this area, such as commercial applications and cuts in production costs.
There’s still so much to discover in material science, geometric shapes and how they interact in given circumstances or in natural environment
It’s amazing how such small word as physics can encompass Everything that exists or will exist even those that stopped exist but existed before,, how they act and react and influence and manipulate other materials changing it’s entire structure and properties