YOU are FAKE NEWS. Hydro JET propulsion (ELECTRIC) and MHD (magneto hydrodynamic drive) are Examples of MORE Efficient MARINE propulsion . there is also the CASE to be said about 100% Electric Hydrofoil as Efficient propulsion. TwoBitdaVinci - the BEST propeller, is NO propeller in the FIRST place.
The math is wrong. Fishing boat and merchant ships spend most of their time at a set speed. The propeller is chosen specifically for that set speed where the efficiency difference becomes negligible.
Sacred Baloney 22 seconds ago Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
Sacred Baloney 22 seconds ago Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
I'm writing this in my 38ft liveaboard boat lol. 2x 380hp Volvo diesels, planing Hull, and 25 knots. The same engines are rated at lower hp and rpm as you move from 15 tonne pleasure craft to commercial vessels, and in my case I can only use full power for a short time. So while more speed is ALWAYS nice, I'd pay a LOT if I could use my current top speed constantly, using less fuel which isn't just a saving but my range increases. There are way more benefits then cost, an engine working less hard will last longer. I'm super pumped - thank you! Hey I wonder if prop walk is reduced? 🤔
I work in patents, and I do a lot of work in helicopters and UAVs. Toroidal props are definitely not a new discovery by any stretch. I was reading a patent from 1895 the other day that was pretty good prior art against MIT's toroidal propeller patent. I've seen lots of other patients in my work over the last few years to do with toroidal, loop, and other tip-joined propellers
I can think of an area where lots of drones are used where efficiency may take second place to sound reduction. Think of where a stealthy drone could deliver a payload without alerting the recipients. In this area, the drones must be flown at a relatively high altitude to avoid detection which then reduces the accuracy of the drop of the payload. Reduce the noise, reduce the altitude, increase the accuracy.
If you look at water pumps, there are two types of impellers. Closed impeller like the torodial boat propeller and an open design normally used for trash water pumps. The open design is lower pressure but is less prone to trash being stuck in the flow through impeller. However I think this guy deserves all the applause he can get for his observation and application to improve boat propeller design.
Sacred Baloney 22 seconds ago Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
@@sacredbaloney : - if their original prop was only 38% as stated, this is totally possible. - if the prop was lightly loaded, "efficiency" increases. The target water speed and disk loading is extremely relevant (fuel efficiency - comparisons with the same hull - would be great) - ie was the replacement prop thee sam diameter and effective pitch??
@@sacredbaloney Agreed that number seems off. It would be 105% of 90%. IIRC these propppelers and a standard propeller need to be designed specifically for a certain speed and torque to get the most efficiency. These are better generally but show more promise for certain speeds and applications. That is what I was told. Also just copying the same design doesn't quite work as well as people think from the small tests I've seen people do on YT. The biggest benefit is durability. Cavitation really does a number on props. Wonder if the Navy has already designed one for their submarines and are having issues manufacturing it.
Sacred Baloney 22 seconds ago Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
@@TwoBitDaVinci Sure, efficiency. But not speed. Cargo ships are displacement hulls, not planing hulls like a speedboat. Their speed limit is set by their very design.
@@davidmccarthy6061 On the long run it will, first a shipping company will adopt the innovation, undercut its competition and then the rest will adopt it if it proves successful. It is deflationary in the long run
This will hopefully make electric ships viable. Hydrogen will problably be the fuel to start with but for short trips and small boats battery will be cheaper.. Also in combination wuth using modern sails will drive the cost of shipping down.
i think the ship of the future is a hydrogen / battery electric hybrid... fairly big battery, and for short trips dont even need hydrogen, and also solar ... i so want to build a boat like this lol but they're huge money pits
@@TwoBitDaVinci -- Sacred Baloney 22 seconds ago Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
One thing that is promising about this design is that it isn't that complicated. It definitely isn't as easy to manufacture as the traditional design, but I don't see anything in there that couldn't be cast or injection molded. It seems like the $5000 price tag isn't going to be the price forever, right now they can charge that much because they have no competition, but I suspect that similar designs will soon offer similar benefits at much lower prices, and they will bring the price down.
They're precision-machining this from fairly expensive metal. Getting the Tesla engineering team to make a giga press casting might not even work. Those castings need to be cut out. They're meant for structure, not hydrodynamic precision. My guess is an inferior product (both in efficiency & lifespan) could be made (at scale, eventually) for $700. But for a precision stainless steel the low bound will be at least $1,000 (which would be easily repaid in fuel) and worth the efficiency boost for electric.
@@Nphen They are definitely marketing a high end product, and there is no doubt that you can get some improvements from going for high quality material and precision manufacturing, and those improvements can definitely be worthwhile. But it is also often possible to get most of the improvements at a far lower cost too, which makes scaling the invention up to mass market and actually getting it implemented happen much more quickly.
Right now they are individually CNC machined from a solid block of stainless steel in a 5 axis Heller Machining CNC production facility. Nothing cheap about that process, about the most expensive way to make a part.
This is too important an advance to have it kept as a boutique item that only the rich can afford. They need to move to license this patent ASAP to other manufacturers. This technology could save billions of gallons per year and all the associated emissions. It's too important to kept under one low volume manufacturer.
@@bored588 Yeah. It's one of those seemingly simple things in hindsight but there's a seemingly infinite range of shapes to try and each one takes at least a little testing. Whether it functions in simulations the same way it functions in the real world is another issue.
There are specific technologies that can be used to make propellers much more efficient, and the changes are subtle. The profile of the blade should be made to maximize laminar boundary layer flow for a substantial reduction in propeller drag and improvement in efficiency. Its possible to obtain low 90% range efficiency with modern design software and manufacturing techniques, (5-axis CNC). The problem with extensive laminar flow is also increased cavitation due to shorter distance to obtain the pressure recovery. And the fact that barnacles, moss, slime will degrade the laminar performance to a point worse than a properly designed conventional propeller. All of these issues, save cavitation, are present in aeronautical propeller design.
@@captspeedy1899 Manufacturing processes got much better over the last decades. There's no way to build a good toroidal propeller without a modern CNC machine, since you need complex toolpaths that are only possible to calculate with modern computers. Also 3d-printing helps massively
I think it would be unlikely for high power. The extra material requirements I doubt would cover the efficiency gains, that's even before you begin figuring out how to transport the thing to the site. With current blades already past 100m in length and 40,000kgs I can't see it being feasible for transportation. The aero elasticity of a structure that shape and size would be very interesting to study though.
@@jakbain1337 Material/efficiency wise I'd assume it can be worth it, as it makes such a big improvement on here. I agree with the transport issue, it will only be possible up to a certain size
I wonder if this is related to the efficiency increase of ducted fans over open circumference fans (in both motors and generators). A propeller forces the fluid away from the propeller shaft, wasting energy. If a cylinder around the propeller blocks this and forces the air to go parallel to the shaft, then there is a more efficient transfer of energy. (If I remember correctly, ducted fans are twice as efficient.)
IP/patents serve a purpose, but the system definitely needs serious reforms. AI behemoths with super computers will increasingly be able to exploit our current system.
Without patents there would be no technological progress as people would have no benefits as everyone will sell it without paying the research and development cost
I've seen a number of people on RUclips talking about this propeller design,but I think you're the first to really delve into the history of similar prop and screw development. This was a very interesting and informative viewing experience. 😃👍
John Ericsson was working in the US, but he was definitely a Swede. Like his brother Nils Ericsson, he was a very successful inventor. Nils remained in Sweden and was instrumental in building the Swedish railways.
But he is half or atleast a little right....Wiki says he become an american citizen 1848 but he designed the prop b4....when he was still swe citizen, but i guess citizenship does not make you sombody else....
The issue is a lot of the people you see on RUclips just make Toroidal propeller designs, more or less , on a trial and error methodology without any understanding or knowledge of aerodynamics/hydrodynamics
This will really be great after the $5000 price tag comes down to a level that recreational boaters will pay for. Propeller thieves will become the new catalyst converter thieves.
Would love to see the effeciency on something like a hydrofoil boat with a Toroidal Propellers. See if if the efficiency is exponentional once it comes out of the water. Such a great breakthrough!
There is an ancient Egyptian artifact, that very closely resembles this prop. It is on display in the Egyptian Museum and should be easy to find if you are interested. It has been a mystery what its function might have been.
I imagine this could significantly increase the capabilities of military submarines. If the new propellers generate less cavitation, which they seem to, it would allow submarines to move more quickly while remaining quiet.
Submarine screws are designed to operate at lower RPM and are already optimized for less cavitation then even this. The main efficiency increase here is due to a reduction of blade tip vortices. This design just also happens to double the number of blades and to place them not all equal angles from each other as well as having them support each other
Ship propellers are bigger than some peoples homes , you will always have slip in water and even more in air , there is no way to make 100% effective propellers . In water you get more effective with spinning propeller slower , that lowers cavitation risk , you can also increase the pitch and size of blades , when your RPM is 100 . Cavitation happens when propeller causes so low pressure on one side of blade that it vaporizes water , faster the propeller spins , more cavitation you get and that eats up you propeller and can be easily heard by military .
Patents by Myers/Davies (1892 - Jan 19 and 26) and Sugden (1967-70) show great insight into the state of the art - long before CFD was available. Propeller thrust is highly speed relative. ie, at Zero speed - static thrust is of dubious relevance depending on the design metrics (static thrust is really measuring pumping efficiency - mass of fluid accelerated to some final velocity, [general derivations, Force = mass * acceleration, power = Work/time = (Force*distance)/time = F*Velocity ]-- no transport work is being performed), at some design "speed" - Power being defined as Velocity multiplied by force (m/s * Newtons = Watts) it would be interesting to see comparison velocity vs thrust curves. $5k for a replacement propeller. The recreational user will only get bragging advantage - at a great cost. The problem with Rotorcraft "loop props" - flow vectors are much more complex than for an axial "airscrew" /water screw / prop as used on- aeroplane or conventional boat. With all rotorcraft, (unless converting to fixedwing in level flight) propeller advance ration have no relation to the aricraft's forward velocity, tips which are not functional - in the thrust vector direction, most likely only create drag and not the stated benefit - unloaded tips - streamlines conformal to path vector - are more important for multirotor "vortex reduction" than boats or fixedwing aeroplanes. Variable flight regimes further complicates optimal design (ie stable hover - with low translational speeds through to high vertical speeds and transitioning to high forward velocity).
It didn't. Reproducing the claims of the MIT paper by amateurs and professional engineers has proven to be a bit difficult and complicated. For one the sound reduction happens in a specific range of noise that itself doesn't seem to translate to DBs noticably, and there seems to be some disagreememt on how efficient they actually are in terms of energy consumption and airflow. Critics have offered that the reproductions aren't following the original specs to the letter, but the original publication is too scant on the details to be able to do that, such as it doesn't give precise dimensions or blade pitch. So for right now the safe bet is to say it's just a neat idea, it also may not function as well in air, because it could just be underdeveloped.
Main problem that I see with th "Hoop Blade" design is that with the hoops, more lake/seaborn plant life would get jammed in the prop... As an avid Lake/Ocean (Puget Sound) fisherman, I get crud wrapped around my "standard" prop all of the time. (Seaweed Happens) Although I am only about 02:00 into this video, I have to add my opinion/voice to this "Next Generation" prop.
That's a very good point. This is why it's great to have a community as diverse as this one. Lots of points of view and different perspectives, all of them valuable.
As a mechanical engineer too, I draw a very different conclusion: boat propellers must often be very poorly suited to the boat they're attached to. They are operating way outside of their optimum angle of attack, giving very low efficiencies. On the other hand, aircraft propellers typically operate at up to 90% efficiency. Variable pitched propellers are able to maintain operation near that 90% for most of an aircraft's normal speed range. I don't see an easy way of achieving variable pitch on the new propeller design. I would really like to see wind tunnel test data for efficiency over a wide speed range, to see whether the real benefit of this new design is wider speed range at decent efficiency. That could render variable pitch redundant, which would be a good way to reduce cost and failure modes. Would love to see a more detailed (nerdy) follow up 🙂
I liken it a bit to turbine designs. If you can limit operation to a narrow band of speeds, you can optimize the design for that. But a boat propeller has to operate under a wide range. Sure, there is a 'cruising speed' that you can optimize for, but then you've probably compromised on the 'top speed' available. And of course there are times you have to operate at very low speeds (harbors, no-wake zones, etc...) and you wouldn't want it to operate terribly poor then. And until you put the prop on a particular hull/ engine combination you can't really know for sure what the 'optimal' speed will be.
You can clearly see there's way less cavitation under water. Maybe the original propeller was bad, but with 200 years of making them the charts should be well established.
7:54 your fuel price figures may be true for the US but in most of the world your video is reaching, fuel is 2-3x more expensive yet! With just a bit more boat usage, it's possible it could pay for itself in one year in the Greek islands, or around the Nordic countries or Hong Kong, Philippines, or Japan's inland sea.
They remind me of the simple hand windmills we got as kids, a short garden cane with a foil windmill on the top. uncannily similar design but the propeller version is elongated. 🤓🤓🤓
We tried a few of these on small engines. They tend to trap weeds and other detritus in the blade loops. You will practically need to stop the engine, get the prop out of the water and clear it. Great idea in theory, but in real world use it sucks.
So the problem with the other pattens is they don't twist at the top its simply a prop with a hole in the center thus leaving a leading edge which will create cavitation. This elimination of cavitation is why the new props work so well
My thoughts on the design patent stuff, is that neither Ford nor Ferrari invented the automobile... but to deny their impact on the industry over such a technicality would be such a disservice. There's a huge difference between having an idea, and implementing it well. That's what separates the Engineer from the Scientist... and to take it another level, the Tradesman from the Engineer. One is not superior to the other, just different stages of the game, requiring different expertise. Outstanding video!
circular wing still have wing tip vortex. Wing tip vortex form not because of the wing tip, it's due to the span wise pressure flow from under the wing try to recombine with the flow above the wing. In a circular win, the recombination event will just happen outside of the circle instead of inside. You still have a pair of "effective" wing tips at the 0 degree and 180 degrees direction. You could eliminate wing tip vortex by eliminate the pressure difference, but you will generate no lift in that case.
Some of the potential use cases for the air-toroidal propeller I'm not sure if they will work. Helicopters, and many large prop planes change their thrust not by rotational speed, but by variable pitch prop blades. This allows the (usually) hydrocarbon fuel motors/engines to run at their most efficient speed in their torque curve. Most modern helicopters are an even more special case requiring variable pitch blades because they change the blade pitch in different quadrants of the 360 rotation to adjust the amount of lift side to side and front to back for roll and pitch control of the craft. None of the toroidal propeller designs that I've seen would be able to vary the pitch of the blades. Unless there are some design enhancements that I'm not aware of (which could very well be.) Maybe if prop planes convert to electric motors toroidal props would be useful because electric motors have a much flatter torque curve, so then variable thrust could be from variable speed (like quad copter drones do it).
These props also dramatically reduce cavitation. That reduces propeller erosion, so they should last much longer than regular props. Less cavitation also reduces underwater noise, so there may be a benefit to marine life.
Reduce cavitation??? Is it your statement based on investigation or just a blunt wish? I will say it will increase cavitation because a lot of flow interaction between multiple 3D blades
The pumps of Saturn 5 rocket engines were standard speed boat propeller blades which are designed to move liquid. It would be interesting to build a pump using toroidal propellers and see if high(er) pressure could be achieved. All conventional liquid fuel rocket engines are based on pressure thrust so more head pressure could produce more powerful engines.
There are so many things a boat operator can do to increase fuel efficiency and top speed that requires knowledge. They dont bother to learn so they need special props lol
This is good for fixed pitch propeller, where it is the engine speed that change. But on many applications, like wind turbine, helicopters of propeller airplane, the propeller stay mostly at the same speed and it’s the pitch that varies. That design doesn’t allowed that. Also, i don’t see benefit when the blades are enclosed like in a turbofan engine, since there’s no vortex at the end of the blade like in normal propeller. Don’t get me wrong, there is loads of applications, including ship, that it is very good. I just thought it was worth saying
It's hard for me to get excited about improvements in shipping efficiency. Time and time again, the result of breakthroughs to save costs haven't translated into lower costs for customers but rather greater profits for owners.
If they can profit more by saving fuel and burning less of it, im OK with that. All we need to do as a country is overturn Citizens United and the rest of the pieces will fall in place.
Generating lower costs for consumers won't produce an R&D budget for them. The reality of cost-of-capital is that it needs to be paid by revenue. The reality of customer's costs is that they'll remain at whatever the customers will still pay. (Witness gas prices.)
That is a typical socialist comment. Why don't you go and put your house on the line and invest in shipping companies? The sad reality is that many shipping companies run at a LOSS.
@@77goanywhere Not sure how that triggered you, but nothing can run at a loss (or LOSS) for long. Even it it was the CU decision post, that's about not supporting corporatism, rather than socialism... A lot of folks are confused by that.
Sorry have to wonder? If it is over 100% efficient what happens when the gas tank overflows? From all the gas going back into it that it must be making?
We do too, actually we even reached out to a Ev boat manufacturer we are in contact with to see if they are going to be using this tech....hope they will.
I drew something similar when I was still in school 20 years ago. It is important not to waste kinetic energy by pushing water sideways. Also most don't consider the acceleration of water along the propeler. Also it's different for open propelers or in a casing... also desired cruise speed and max acceleration dictates which propeler design is the best. For high performance propeling, cavitating and durability of the component is also considered. I don't really consider this to be all that revolutionary... up until now the private sector was just not really interested in doing anything overly complicated or expensive or adapting the shape to the use case.
@@Berend-ov8of Another option (if aforemention cannot be prevented) would be to limit wasted impulse by putting a second contraption behind the rotor blades rectifying the direction the pushed water flows in (suboptimal, since water/air behind a rotor is subject to whirls and turbulence). Second would be to put something in front of the blades to let the current hit the blades at another angle. Third would be to encase the blades having a closed propulsion system sideways. Many such solutions increase the resistance against the current though. The soluton in the video may be compared to winglets bent into the turning direction of the blades, while directly being prolonged back to the rotor axis to increase durability/sturdyness as well as forming a secondary rotor blade. Elegant solution in comparison to what other engineers do in the industry.
@@skeltek7487 Yet another solution would be to pull water in from the sides, which is more of an accoustic event. Accoustics is not often intergrated in power design, but in this case it obviously is. Either by chance or on purpose, resulting not only in noticable noise reduction, but also in that increased efficiency. It does result in a prop with a distinct optimal tune setting, but at that setting, the results are quite surprizing. Plus as a general rule, any activity that isn't there, can't cause damage. I really like this technology. The Sharrow prop is more of a carefully tuned open pump than a prop. Cavitation is expesive. As weird as it may sound, It basically makes water instantaneously boil. Just look at the thing and imagine the shape of water it creates as it spins. Compared to that, an ordinary prop looks like the hysterical maid who just saw a mouse.
@@Berend-ov8of Well, a lot of noise is emitted by the pressure fluctuations of water being pushed sideways by the rotor blades whenever one passes that angle and not being pushed when it does not. 'Pulling' water from the sides is problematic, since the maximum speed at which water may flow sideways is limited by the speed of sound in water (not exactly but it correlates to that). The maximum speed at which water could enter a surface area sideways would be limited and cap the maximum performance, while water flowing from the front to the blades would increase linearly proportional with speed. I agree with the comparison with an open pump, but even there cavitation is possible. I wonder if there will be a high-speed version with slightly different angles in the rotor loops.
@@Berend-ov8of Actually a fish is indeed pushing water backwards mostly. The stream on the side of the body diverts the water to flow antiradially towards the fishs major axis before it reaches its tail fins. The tail fins transform the antiradial motion of water into retrograde motion of the water, which is pretty much antiparallel to the fishs intended direction of movement. Evolution has made fish waste as little energy as possible for those which developed with a focus on speed... It may look like a fast fish is pushing water mostly sideways, but you got to consider the direction the water flows before and after the tail fin excerts its force...
BUT ? Do these also have the same effeminacy at really low RPM ?? CUZ a big cargo ship the motor top out around 90 - 100 RPM, and i dont think the propeller spin any faster than that. I am pretty sure Maersk shipping would be all over this if it was making any sense.
One of the main advantages for propellors is, that it would probably last much, much longer. The lack of cavitation, as evidenced by the lack of 'tip' bubble streams, would eliminate one of the greatest dangers to conventional propellors.
The benefits of the new designs are sometimes misunderstood. I was unsure about the technology until your video. I was wondering if the toroidal fan shape had been applied to heat pumps. Which to me would be the most obvious place for them.
LOL... the prop costs $5000 to make currently... so it wouldn't save you anything in a recreational vessel seeing only occasional use (for that market you need to cost $500-1000 ), it might save you some in a commercial one used daily. Assuming it lasts at least several years of constant use without getting damaged.
@@Wingnut353 true he states they are all custom to the engine driving them as they are fragile and need to be tuned to the stress of the engine torque if it could save on shipping lanes burn rate that would be great don't think it is about saving money but about usage efficiency
One thing from being a person that lives by boat and drives a boat to get back and forth from our house to the marina. We end up hitting sticks and small things lots and traditional crops get damaged I wonder how long these would last
i really want to get the raw test data for this propeller, information like motor torque and rpm (power) and thrust produced compared against a control propeller of appropriate size and RPM. its very rare that the efficiency of something is improved by 40% with a new design like this. also with this information missing its difficult to make an informed decision if this propeller is worth the extra $$$
Noise reduction is related with efficiency since the energy is dissipated mainly in the form of mechanical vibration (noise) and increase of temperature. A propulsion system that emit less noise is probably more efficient. That happens with electric motors, for example.
Interesting development, not sure why one should cost so much (other than corporate price gouging a 'new and improved' product). I know the Navy has used 'shrouded propulsors' on modern submarines, but obviously there is very little unclassified information about them. The fact that others had similar designs before without reporting such dramatic improvements leaves me... skeptical. I'll hold onto my money for now, wait and see.
These props have to be machined on a CNC from solid blocks of stainless steel. This is because the shape of the propeller is impossible to cast in a sand mold. Most of a solid block will have to be cut away and recycled, so there's a high material cost. There's some cost recovery from the prime recycle, but its a fraction of the virgin material cost. Additionally, CNC machine time cost increases exponentially with size. Lastly, these are made one at a time and custom order. Traditional propellers are made by casting the steel into a sand mold and can be made in large batches, dozens or even hundreds at a time. Not everything is as simple as 'corporate greed'.
Check out the BoatTests review. At cruising RPM, a powerboat was a whopping 11knots faster, 86%, in the middle of the power and, with decreasing returns until it topped out at the same speed as the stock propeller at the maximum RPM. It doesn’t produce as much cavitation so it doesn’t slip like a normal propeller.
And it’s not corporate greed. It’s from small shop in Michigan, they produce all of their propellers in-house with high-end CNC machines, and it’s the only product they make. It’s a bespoke product, and that commands bespoke prices.
@@Neberheim would it be fair to say that, if these were mass manufactured at similar scale to the traditional propellors, then the price would reduce to be in the same price ballpark?
I'm not a mechanical engineer, but as a lowly electrical engineer it strikes me as a bit optimistic the efficiency gains measured with small boats and outboard engines translated to shipping. Small boats typically are planing hull designs and engine and prop speeds in the range of hundreds to thousands RPM. Small improvements in prop design would translate to large efficiency improvement. However, shipping generally use displacement hull and slower engine RPM, by a level of magnitude. I'm not an expert, but guess, the same is true with prop speeds. So my guess would be with lower prop speed, actual prop design would be less critical.
Could the toroidal propeller concept be applied to variable-pitch propellers? For example, in a wind turbine application, could the blades be replaced by loops? It would not need to be a full loop, just the tip of the blade could be looped to mitigate tip vortices.
@@greatcondor8678 I don't see this on petroleum-based airplanes. They run their engines at near to the optimum rotational speed and adjust thrust with variable pitch. Using variable rotational speed to vary the thrust will run the engine(s) in non-fuel efficient speeds. The engine would need to also change to a type that has a much flatter torque curve, like electric motors.
The same rules would apply to lawnmower blades, fan blades, helicopter blades, and so forth. It makes sense, since you increase the working force by double so the output force would be double.
Lawn mower blades are actually a really big deal, if your not cutting efficiency then you might have to cut more often or need a higher powered mower just to get the job done.
@@TwoBitDaVinci I wonder if a more flexible material would improve the idea as well, where applicable. Thinner but stronger metal or even some other kind of material depending on the application- water, air, or organic material... 🤔
Helicopters vary the pitch of their blades asymmetrically to maneuver. To move forward, for example, whatever blade is over the tail experiences the most severe pitch angle. Blade pitch increases to a maximum over the tail and then decreases as the blade moves towards the front. It still produces lift in the front just less than it does while it is in the back. Each blade attaches to a swash plate, which is just a rotary coupling, via pitch control rods. Applying this technology to that kind of mechanism would be a monster challenge. Some sort of elastomeric loop end for each pair of blades? The tail rotor would be easier as all of the blades change pitch in unison. A place to start.
I started that comment intending to say it just wasn't feasible to apply this to helicopters but by the end I started to get ideas. My vote has shifted from no to a slight maybe.
Now this is something that can really help reducing carbon outputs, not to mention improving the impact of motorised vessels on the marine environment. Well done.
Been looking for a torroidal blade for my wood- burner fan - sadly not found any yet. Need a good simulation software package to optimise the design and 3D print one myself.
Most of the use of numbers was comparisons, that is before and after. In such a case the units are pretty much meaningless anyway. Aside from that, the world over, speed is measured in kts, not Kph or mph but true international units (SI units) would be meters per second... not sure how that really relates to anything useful. And of course US gallons are not gallons but 83%-ish gallons. For all the advances in measurement, we may as well be measuring fuel consumption in furlongs per firkin.
Unable to do simple conversions from Liberian units nor compare percentages - there's a sad statement on folks suffering from innumeracy... I tend to prefer SI units as well, but wow, Siri et al seem to handle that for folks who can't work a calculator.
You're behind the times, the first marine propellor was invented over 100 years earlier by the American invehtor Bushnell for his submarine 'Turtle', built to attack British warships in the War of Independence. The propellors, made in 1775, were powered by hand and worked well, but when he tried to attach an explosive charge to the battleship Eagle, he failed. The reason was that all British warships had copper bottoms, and the auger that Bushnell used to fix the charge could penetrate wood but not copper. The sub was lost the following year when the transport carrying it was sunk. It's still down there somewhere and worth a fortune!
Interesting design but I wonder if that propeller design can handle the intense stresses of larger commercial craft. Big difference in moving a lightweight sport boat and a mega transport cargo ship and you have to consider that many of those cargo ships travel though seas with icebergs etc.
umm, no. There are still spinning tips and the weight would increase. notice the thickness of the chord on these new props is much thicker than current designs.
Man, between the one stroke cycle and this 105 percent violation of physics, it's going to over-generate it's own fuel. You'll have to stop every few miles to dump fuel out.
My solar electric pontoon boats and the canoe would benefit from the range increase, speed, and load performance. It will need to be a more practical and economical product.
@@markplott4820 More efficient than what? Electric motors are typically 5 times more efficient than ICE engines, but jet drives are half that of prop efficiency. So how does that play out with all the watercraft types in net-ton-miles per kWh? What does efficiency mean when for entertainment?
I wonder how much of the pricetag on those boat props is the actual more complex manufacturing and how much boils down to intellectual property markup...
Switching to this design would not accommodate constant speed propellers (prop pitch changes instead of engine speed), which means changing over the entire engine system. Not that it would be prohibitive, but it’s not always as simple as swapping out a propeller. Still, it would be amazing for this to take over the industry!
the major engineering challenge I see with this is variable pitch control In aircraft in particular, propeller pitch is changed continuously as the velocity and altitude changes to maintain peak efficiency. with a design like this it will be quite difficult to achieve pitch variation as the entire blade effectively needs to be flexible also, in regards to DIY 3D printing tests: 3D printer materials are not aerodynamically optimal. like, at all the finish on a 3D printed item is far rougher than aviation grade manufacturing, so its not really surprising that DIY tests have not found as much of a gain as the researchers
JAPAN , has been using HEAT pumps in Residential/small business cooling/heat since 1986 !!!!! America & EU are OUTDATED. also since 1986, JAPAN has been using Localized in-home Instant water heaters , located in Kitchen & Bath.
@@markplott4820 We use heat pumps on military bases for cooling and water heating. Basically move heat from the A/C's supply to the hot water tap supply
To be able to lecture absolutely accurately about lift/propulsion/drive on a toroidal propeller requires either knowing everything about dynamic lift or nothing at all: "Axiom concerning the synergy of CIRCULATION and DYNAMIC LIFT: "Dynamic lift results from the struggle and unity of opposites, the convergence of circulation and lateral Draftflow (1st dialectical law). Within lateral flow, every object that is circumferentially surrounded, every entity within the universe, regardless of size, weight, shape, or nature, experiences a lateral force - DYNAMIC LIFT. Dynamic lift is the lateral force that any circumferentially surrounded entity experiences within an additional, lateral flow. Lateral flow, as indicated by the term 'lateral,' excludes (literally/in the sense of words) a flow direction parallel to the axis of circulation. The necessary circulation can be a) aside from its spontaneous generation at an appropriately directed "slanting" angle of airfoil profiles (sails, kite-dragons, wings, turbines, propellers, toroidalpropellers, ship screws, ascending larger, non-spherical air bubbles in liquids) with respect to that lateral flow, b) a consequent circulation from rotation (akin to falling confetti in a gaseous medium with ensuing friction/interlocking action!) c) also achieved externally, by switching, controlling, changing direction, and switching direction. For the purpose of generating the desired lift in a switchable, controllable, and directionally adjustable manner. Circulation and lift occur within lateral flow either together, interacting or not at all. This synergistic interplay is only proportional within a very small range. For instance, the KUTTA lift formula (factor times factor times factor equals product) mathematically implies proportionality, but it is limited by the effect of the LAW OF CONSERVATION OF ENERGY to a specific range of validity (alleged "rule of thumb" without explicit justification by the action of the law of conservation of energy. Lift increase terminates roughly between attaining three and a half to four times the circulation speed relative to the speed of lateral flow, (documented in the letter from the Göttingen wind tunnel operator to the engineer Mr. FLETTNER during the assessment of his rotor intention/invention)."
Could you talk about how we make magnets with an eye toward generating the forces directionally, specifically the opposing forces that allow one to appear to dangle in space. If we can direct this, perhaps we can find the propulsion methodology to get to the stars?
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She is also my personal trader, crypto analyst and account manager. With an initial invested capital of $8000,it yielded returns of over $36000 within two weeks of trading. I was really impressed by the profit Actualized
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I have broken through 45k, 72k and got my eyes on 120k! Champagne stays popping. She is too awesome. People prefer to spend money on liabilities, Rather than investing in assets and be very profitable.
Interesting. I notice that all the shown test boats are traveling at planing speed... probably because you would have to be wasting fuel at the rate needed to plane large, heavy, lumps of plastic to make these very pricey blades make sense. I guess being rich enough to afford such toys helps too. One has to wonder how well these would fare against variable pitch props at a speed they are not designed for. How well do they do at displacement speeds? How much resistance do they produce when they are at rest but the boat is moving, for example a sail is being used or a single screw in a double screw vessel is being run. How well do they work in reverse? Another comparison that needs to be made would be to large diameter, slow turning screws such as those used on large freight vessels where tip vortices, while still present, are much lower. As a side note: The idea they could be used in a helicopter makes no sense as the angle of attack of each blade is different depending on the portion arc the blade is positioned at each microsecond of time. Also, the blades are flexible and rely on centrifugal force to keep them in place so they can be light enough. A solid blade of this new design would have to be very heavy just to hold it's shape and at the same time be able to change its shape continuously over each rotation. Not going to happen. That sounds like patent language trying to cover every possible use of this "invention". In all, I think these props are great for exactly what they are advertised for, go fast boats with small high rpm props at cruising speed, which to be fair, is where a lot of these kinds of boats spend most of their run time.
To add some info, I've used printed versions of these props on quads and while it is quieter it also puts a larger load on the motors. A 3 bladed version puts almost as much load as a normal 6 bladed prop, not sure how it scales with size yet but the difference from a 6 blade is almost nothing in terms of power use and load. Though it is slightly quieter then a 6 blade
I simply do not understand why, in all of the videos and reports I have seen on the subject of toroidal propellers, I have never seen or heard mentioned that the major difference between the mediums of water and air is that water is non-compressible and air is compressible. This certainly must affect performance.
They cannot be used for variable pitch applications. Many ships use VP, most propeller aircraft have variable pitch. It would be a boon to heavy shipping as they are huge fuel consumers and harm the ocean environment with the noise.
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YOU are FAKE NEWS.
Hydro JET propulsion (ELECTRIC) and MHD (magneto hydrodynamic drive) are Examples of MORE Efficient MARINE propulsion . there is also the CASE to be said about 100% Electric Hydrofoil as Efficient propulsion.
TwoBitdaVinci - the BEST propeller, is NO propeller in the FIRST place.
What about energy generation? as in wind mills turbines
@Mark Plott do those technologies work for larger ship?
The math is wrong. Fishing boat and merchant ships spend most of their time at a set speed. The propeller is chosen specifically for that set speed where the efficiency difference becomes negligible.
Sacred Baloney
22 seconds ago
Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
Props to this channel for propelling this revolutionary technology to the masses!
I see what you did there 😉
ooooof 😆
Sounds as corny as something the most electrifying man in entertainment aka the rock would say. 😀
Properly said!!
Sacred Baloney
22 seconds ago
Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
I'm writing this in my 38ft liveaboard boat lol. 2x 380hp Volvo diesels, planing Hull, and 25 knots. The same engines are rated at lower hp and rpm as you move from 15 tonne pleasure craft to commercial vessels, and in my case I can only use full power for a short time. So while more speed is ALWAYS nice, I'd pay a LOT if I could use my current top speed constantly, using less fuel which isn't just a saving but my range increases. There are way more benefits then cost, an engine working less hard will last longer. I'm super pumped - thank you! Hey I wonder if prop walk is reduced? 🤔
I work in patents, and I do a lot of work in helicopters and UAVs. Toroidal props are definitely not a new discovery by any stretch. I was reading a patent from 1895 the other day that was pretty good prior art against MIT's toroidal propeller patent. I've seen lots of other patients in my work over the last few years to do with toroidal, loop, and other tip-joined propellers
What kind of patients were they😂
I can think of an area where lots of drones are used where efficiency may take second place to sound reduction. Think of where a stealthy drone could deliver a payload without alerting the recipients. In this area, the drones must be flown at a relatively high altitude to avoid detection which then reduces the accuracy of the drop of the payload. Reduce the noise, reduce the altitude, increase the accuracy.
We have a video dropping on Thursday discussing just that.
If you look at water pumps, there are two types of impellers. Closed impeller like the torodial boat propeller and an open design normally used for trash water pumps. The open design is lower pressure but is less prone to trash being stuck in the flow through impeller. However I think this guy deserves all the applause he can get for his observation and application to improve boat propeller design.
Swap-on improvements are some of the most impactful, especially with the impressive gains these props bring.
Quick and easy often makes for the most used of improvements at scale
Sacred Baloney
22 seconds ago
Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
@@sacredbaloney : - if their original prop was only 38% as stated, this is totally possible.
- if the prop was lightly loaded, "efficiency" increases.
The target water speed and disk loading is extremely relevant (fuel efficiency - comparisons with the same hull - would be great) - ie was the replacement prop thee sam diameter and effective pitch??
@@sacredbaloney did you watch the video, as in, the whole video?
@@sacredbaloney Agreed that number seems off. It would be 105% of 90%. IIRC these propppelers and a standard propeller need to be designed specifically for a certain speed and torque to get the most efficiency. These are better generally but show more promise for certain speeds and applications.
That is what I was told. Also just copying the same design doesn't quite work as well as people think from the small tests I've seen people do on YT.
The biggest benefit is durability. Cavitation really does a number on props. Wonder if the Navy has already designed one for their submarines and are having issues manufacturing it.
The knock on effects of this could be massive. Cutting shipping costs is huge
yes shipping efficiencies are where the big savings can come in.
More likely increased profits than a trickle down to consumers but if it helps them jump to electric then we all win.
Sacred Baloney
22 seconds ago
Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
@@TwoBitDaVinci Sure, efficiency. But not speed. Cargo ships are displacement hulls, not planing hulls like a speedboat. Their speed limit is set by their very design.
@@davidmccarthy6061 On the long run it will, first a shipping company will adopt the innovation, undercut its competition and then the rest will adopt it if it proves successful. It is deflationary in the long run
This will hopefully make electric ships viable. Hydrogen will problably be the fuel to start with but for short trips and small boats battery will be cheaper.. Also in combination wuth using modern sails will drive the cost of shipping down.
i think the ship of the future is a hydrogen / battery electric hybrid... fairly big battery, and for short trips dont even need hydrogen, and also solar ... i so want to build a boat like this lol but they're huge money pits
@@TwoBitDaVinci plus a little bit of wind propulsion
@@TwoBitDaVinci Reminds me of an old joke: The two best days of a boat owner's life are when the buy the boat and when they sell the boat. 😆
@@Sembazuru And not necessarily in that order! ;-)
@@TwoBitDaVinci --
Sacred Baloney
22 seconds ago
Increase efficiency by 105%? Nonsense. A standard propeller is at least 75% efficient. A top rated propeller is about 90% efficient. How can you "increase efficiency by 105%"?
One thing that is promising about this design is that it isn't that complicated. It definitely isn't as easy to manufacture as the traditional design, but I don't see anything in there that couldn't be cast or injection molded. It seems like the $5000 price tag isn't going to be the price forever, right now they can charge that much because they have no competition, but I suspect that similar designs will soon offer similar benefits at much lower prices, and they will bring the price down.
They're precision-machining this from fairly expensive metal. Getting the Tesla engineering team to make a giga press casting might not even work. Those castings need to be cut out. They're meant for structure, not hydrodynamic precision. My guess is an inferior product (both in efficiency & lifespan) could be made (at scale, eventually) for $700. But for a precision stainless steel the low bound will be at least $1,000 (which would be easily repaid in fuel) and worth the efficiency boost for electric.
@@Nphen They are definitely marketing a high end product, and there is no doubt that you can get some improvements from going for high quality material and precision manufacturing, and those improvements can definitely be worthwhile. But it is also often possible to get most of the improvements at a far lower cost too, which makes scaling the invention up to mass market and actually getting it implemented happen much more quickly.
Right now they are individually CNC machined from a solid block of stainless steel in a 5 axis Heller Machining CNC production facility. Nothing cheap about that process, about the most expensive way to make a part.
they signed a contract with Yamaha. they will mass produce it and offer it as standard on their motors.
This is too important an advance to have it kept as a boutique item that only the rich can afford. They need to move to license this patent ASAP to other manufacturers. This technology could save billions of gallons per year and all the associated emissions. It's too important to kept under one low volume manufacturer.
12:30 - a "high pitched buzzing sound" is also called a "drone"
As being a swede I was surprised to hear, for the first time, that John Ericsson was not from sweden.
It blows my mind props for boats havent been majorly improved for so long. I just assumed there was a lot of rnd, with wind tunnel tests etc
just not much to do with them, people have tried, just nothing was worth the change, until now atleast.
@@bored588 Yeah. It's one of those seemingly simple things in hindsight but there's a seemingly infinite range of shapes to try and each one takes at least a little testing. Whether it functions in simulations the same way it functions in the real world is another issue.
There are specific technologies that can be used to make propellers much more efficient, and the changes are subtle.
The profile of the blade should be made to maximize laminar boundary layer flow for a substantial reduction in propeller drag and improvement in efficiency. Its possible to obtain low 90% range efficiency with modern design software and manufacturing techniques, (5-axis CNC).
The problem with extensive laminar flow is also increased cavitation due to shorter distance to obtain the pressure recovery.
And the fact that barnacles, moss, slime will degrade the laminar performance to a point worse than a properly designed conventional propeller.
All of these issues, save cavitation, are present in aeronautical propeller design.
its fake and clickbait, you are just gullible
@@bored588 And still not worth the change.
When you consider how long we’ve used propellers, it’s madness to think we’ve only just discovered this
This has been used and open sourced for over 50 years
If you ever owned a boat, you'd see the problem considering the price of these props.
these haven't "just" been "discovered". it's only recently, that we could make it "work" through improved designing and production technology.
@@EchoeOne if this design shape has been known for a long time why wait so long to be used in the real world?
@@captspeedy1899 Manufacturing processes got much better over the last decades. There's no way to build a good toroidal propeller without a modern CNC machine, since you need complex toolpaths that are only possible to calculate with modern computers. Also 3d-printing helps massively
Will also be interesting to see if a type of this can be applied to windgenerators too
I think it would be unlikely for high power. The extra material requirements I doubt would cover the efficiency gains, that's even before you begin figuring out how to transport the thing to the site. With current blades already past 100m in length and 40,000kgs I can't see it being feasible for transportation. The aero elasticity of a structure that shape and size would be very interesting to study though.
@@jakbain1337 Material/efficiency wise I'd assume it can be worth it, as it makes such a big improvement on here. I agree with the transport issue, it will only be possible up to a certain size
I wonder if this is related to the efficiency increase of ducted fans over open circumference fans (in both motors and generators). A propeller forces the fluid away from the propeller shaft, wasting energy. If a cylinder around the propeller blocks this and forces the air to go parallel to the shaft, then there is a more efficient transfer of energy. (If I remember correctly, ducted fans are twice as efficient.)
Amazing prop development! However, for many boaters who have to keep replacing damaged props, it would simply cost too much
Yep, it's a costal deep water prop for sure. Too risky for rocky inland lakes.
Patents hold the worlds progress back
Made in china get away with it though. As long as you are not in US (less lawsuit)
IP/patents serve a purpose, but the system definitely needs serious reforms. AI behemoths with super computers will increasingly be able to exploit our current system.
Without patents there would be no technological progress as people would have no benefits as everyone will sell it without paying the research and development cost
I've seen a number of people on RUclips talking about this propeller design,but I think you're the first to really delve into the history of similar prop and screw development. This was a very interesting and informative viewing experience. 😃👍
John Ericsson was working in the US, but he was definitely a Swede. Like his brother Nils Ericsson, he was a very successful inventor. Nils remained in Sweden and was instrumental in building the Swedish railways.
But he is half or atleast a little right....Wiki says he become an american citizen 1848 but he designed the prop b4....when he was still swe citizen, but i guess citizenship does not make you sombody else....
The issue is a lot of the people you see on RUclips just make Toroidal propeller designs, more or less , on a trial and error methodology without any understanding or knowledge of aerodynamics/hydrodynamics
This will really be great after the $5000 price tag comes down to a level that recreational boaters will pay for. Propeller thieves will become the new catalyst converter thieves.
Oh dang yeah i hope that doesn't happen....
Prop thieves are already a problem for the boating industry
The existence of all these similar older patents demonstrates once again that ideas are cheap. The real challenge is to bring a product to market.
Would love to see the effeciency on something like a hydrofoil boat with a Toroidal Propellers. See if if the efficiency is exponentional once it comes out of the water. Such a great breakthrough!
There is an ancient Egyptian artifact, that very closely resembles this prop. It is on display in the Egyptian Museum and should be easy to find if you are interested. It has been a mystery what its function might have been.
I imagine this could significantly increase the capabilities of military submarines. If the new propellers generate less cavitation, which they seem to, it would allow submarines to move more quickly while remaining quiet.
Submarine screws are designed to operate at lower RPM and are already optimized for less cavitation then even this. The main efficiency increase here is due to a reduction of blade tip vortices. This design just also happens to double the number of blades and to place them not all equal angles from each other as well as having them support each other
Ship propellers are bigger than some peoples homes , you will always have slip in water and even more in air , there is no way to make 100% effective propellers .
In water you get more effective with spinning propeller slower , that lowers cavitation risk , you can also increase the pitch and size of blades , when your RPM is 100 .
Cavitation happens when propeller causes so low pressure on one side of blade that it vaporizes water , faster the propeller spins , more cavitation you get and that eats up you propeller and can be easily heard by military .
In San Diego they cover the sub props.
Patents by Myers/Davies (1892 - Jan 19 and 26) and Sugden (1967-70) show great insight into the state of the art - long before CFD was available.
Propeller thrust is highly speed relative.
ie, at Zero speed - static thrust is of dubious relevance depending on the design metrics (static thrust is really measuring pumping efficiency - mass of fluid accelerated to some final velocity, [general derivations, Force = mass * acceleration, power = Work/time = (Force*distance)/time = F*Velocity ]-- no transport work is being performed), at some design "speed" - Power being defined as Velocity multiplied by force (m/s * Newtons = Watts) it would be interesting to see comparison velocity vs thrust curves.
$5k for a replacement propeller. The recreational user will only get bragging advantage - at a great cost.
The problem with Rotorcraft "loop props" - flow vectors are much more complex than for an axial "airscrew" /water screw / prop as used on- aeroplane or conventional boat. With all rotorcraft, (unless converting to fixedwing in level flight) propeller advance ration have no relation to the aricraft's forward velocity, tips which are not functional - in the thrust vector direction, most likely only create drag and not the stated benefit - unloaded tips - streamlines conformal to path vector - are more important for multirotor "vortex reduction" than boats or fixedwing aeroplanes. Variable flight regimes further complicates optimal design (ie stable hover - with low translational speeds through to high vertical speeds and transitioning to high forward velocity).
I also love accidental discoveries. Radioactivity, velcro and the microwave over are just some that come to mind
Viagra
@@donchristie420 penicillin!
Post it notes!
@@larrybolhuis1049 I love this one!!!
I want to see an, thrust coefficient, torque coefficient, and efficiency against advance coefficient graph for these properlers.
yeah that would be cool
Someone tried this style of blade as a design for a computer fan, kinda neat to see (although I don't know how it compared to conventional fans)
It didn't. Reproducing the claims of the MIT paper by amateurs and professional engineers has proven to be a bit difficult and complicated. For one the sound reduction happens in a specific range of noise that itself doesn't seem to translate to DBs noticably, and there seems to be some disagreememt on how efficient they actually are in terms of energy consumption and airflow.
Critics have offered that the reproductions aren't following the original specs to the letter, but the original publication is too scant on the details to be able to do that, such as it doesn't give precise dimensions or blade pitch.
So for right now the safe bet is to say it's just a neat idea, it also may not function as well in air, because it could just be underdeveloped.
Main problem that I see with th "Hoop Blade" design is that with the hoops, more lake/seaborn plant life would get jammed in the prop...
As an avid Lake/Ocean (Puget Sound) fisherman, I get crud wrapped around my "standard" prop all of the time. (Seaweed Happens)
Although I am only about 02:00 into this video, I have to add my opinion/voice to this "Next Generation" prop.
That's a very good point. This is why it's great to have a community as diverse as this one. Lots of points of view and different perspectives, all of them valuable.
As a mechanical engineer too, I draw a very different conclusion: boat propellers must often be very poorly suited to the boat they're attached to. They are operating way outside of their optimum angle of attack, giving very low efficiencies.
On the other hand, aircraft propellers typically operate at up to 90% efficiency. Variable pitched propellers are able to maintain operation near that 90% for most of an aircraft's normal speed range.
I don't see an easy way of achieving variable pitch on the new propeller design.
I would really like to see wind tunnel test data for efficiency over a wide speed range, to see whether the real benefit of this new design is wider speed range at decent efficiency. That could render variable pitch redundant, which would be a good way to reduce cost and failure modes.
Would love to see a more detailed (nerdy) follow up 🙂
Great points and will do!
I liken it a bit to turbine designs. If you can limit operation to a narrow band of speeds, you can optimize the design for that. But a boat propeller has to operate under a wide range. Sure, there is a 'cruising speed' that you can optimize for, but then you've probably compromised on the 'top speed' available. And of course there are times you have to operate at very low speeds (harbors, no-wake zones, etc...) and you wouldn't want it to operate terribly poor then. And until you put the prop on a particular hull/ engine combination you can't really know for sure what the 'optimal' speed will be.
You can clearly see there's way less cavitation under water.
Maybe the original propeller was bad, but with 200 years of making them the charts should be well established.
@@mikefochtman7164 but current boat propellers aren’t variable pitch, either, I don’t think.
@@J7Handle most cargo ships have variable pitch prop
it reminds me of a scroll compressor, and aircraft props that tends to keep the air from from going out
7:54 your fuel price figures may be true for the US but in most of the world your video is reaching, fuel is 2-3x more expensive yet! With just a bit more boat usage, it's possible it could pay for itself in one year in the Greek islands, or around the Nordic countries or Hong Kong, Philippines, or Japan's inland sea.
They remind me of the simple hand windmills we got as kids, a short garden cane with a foil windmill on the top. uncannily similar design but the propeller version is elongated. 🤓🤓🤓
oh yeah true, I forgot about those
We tried a few of these on small engines. They tend to trap weeds and other detritus in the blade loops. You will practically need to stop the engine, get the prop out of the water and clear it.
Great idea in theory, but in real world use it sucks.
weeds could be a big issue.
@@TwoBitDaVinci maybe if they could sharpen the edges like a razor it could cut as well as propel the boat
@@wonkastudio-johnny That is a bad idea and has been tried it is a fantastic way to mess up your prop.
@@wonkastudio-johnny That has been tried before. The thin sharp edges will chip easily when it hits even a small piece of wood.
So the problem with the other pattens is they don't twist at the top its simply a prop with a hole in the center thus leaving a leading edge which will create cavitation. This elimination of cavitation is why the new props work so well
My thoughts on the design patent stuff, is that neither Ford nor Ferrari invented the automobile... but to deny their impact on the industry over such a technicality would be such a disservice. There's a huge difference between having an idea, and implementing it well. That's what separates the Engineer from the Scientist... and to take it another level, the Tradesman from the Engineer. One is not superior to the other, just different stages of the game, requiring different expertise.
Outstanding video!
The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka!” (I found it!) but “That’s funny …”
- Isaac Asimov
Got to love the innovators. Just don’t use it to _kill_ anyone, we’re already super-efficient at doing that…
Now we can more efficiently fly drones to bomb villages
circular wing still have wing tip vortex. Wing tip vortex form not because of the wing tip, it's due to the span wise pressure flow from under the wing try to recombine with the flow above the wing. In a circular win, the recombination event will just happen outside of the circle instead of inside. You still have a pair of "effective" wing tips at the 0 degree and 180 degrees direction. You could eliminate wing tip vortex by eliminate the pressure difference, but you will generate no lift in that case.
exactly
Some of the potential use cases for the air-toroidal propeller I'm not sure if they will work. Helicopters, and many large prop planes change their thrust not by rotational speed, but by variable pitch prop blades. This allows the (usually) hydrocarbon fuel motors/engines to run at their most efficient speed in their torque curve. Most modern helicopters are an even more special case requiring variable pitch blades because they change the blade pitch in different quadrants of the 360 rotation to adjust the amount of lift side to side and front to back for roll and pitch control of the craft. None of the toroidal propeller designs that I've seen would be able to vary the pitch of the blades. Unless there are some design enhancements that I'm not aware of (which could very well be.) Maybe if prop planes convert to electric motors toroidal props would be useful because electric motors have a much flatter torque curve, so then variable thrust could be from variable speed (like quad copter drones do it).
Nice. You definitely hit the nail on the head.
I just wonder why that new propeller have sharp ending with cavity. Should this be smoove pointy end to prevent cavitation?
These props also dramatically reduce cavitation. That reduces propeller erosion, so they should last much longer than regular props. Less cavitation also reduces underwater noise, so there may be a benefit to marine life.
Reduce cavitation??? Is it your statement based on investigation or just a blunt wish? I will say it will increase cavitation because a lot of flow interaction between multiple 3D blades
kinda expected a mechanical engineer to explain why they're more efficient instead of showing anecdotal evidence supplied by the company -.-'
Any idea how well Toroidal propellers reverse on boats?
There is a video on youtube where they are testing it. In reverse it is also much better then regular prop.
Great question....should work well in reverse also
cool, good to know
The pumps of Saturn 5 rocket engines were standard speed boat propeller blades which are designed to move liquid. It would be interesting to build a pump using toroidal propellers and see if high(er) pressure could be achieved. All conventional liquid fuel rocket engines are based on pressure thrust so more head pressure could produce more powerful engines.
There are so many things a boat operator can do to increase fuel efficiency and top speed that requires knowledge. They dont bother to learn so they need special props lol
"New wave " technology 😂
This is good for fixed pitch propeller, where it is the engine speed that change. But on many applications, like wind turbine, helicopters of propeller airplane, the propeller stay mostly at the same speed and it’s the pitch that varies. That design doesn’t allowed that.
Also, i don’t see benefit when the blades are enclosed like in a turbofan engine, since there’s no vortex at the end of the blade like in normal propeller.
Don’t get me wrong, there is loads of applications, including ship, that it is very good.
I just thought it was worth saying
It's hard for me to get excited about improvements in shipping efficiency. Time and time again, the result of breakthroughs to save costs haven't translated into lower costs for customers but rather greater profits for owners.
yeah often a sad reality,, but hey at least its an improvement better than nothing.
If they can profit more by saving fuel and burning less of it, im OK with that. All we need to do as a country is overturn Citizens United and the rest of the pieces will fall in place.
Generating lower costs for consumers won't produce an R&D budget for them. The reality of cost-of-capital is that it needs to be paid by revenue. The reality of customer's costs is that they'll remain at whatever the customers will still pay. (Witness gas prices.)
That is a typical socialist comment. Why don't you go and put your house on the line and invest in shipping companies? The sad reality is that many shipping companies run at a LOSS.
@@77goanywhere Not sure how that triggered you, but nothing can run at a loss (or LOSS) for long. Even it it was the CU decision post, that's about not supporting corporatism, rather than socialism... A lot of folks are confused by that.
Sorry have to wonder? If it is over 100% efficient what happens when the gas tank overflows? From all the gas going back into it that it must be making?
Want to see this on a EV boat to see if its a game changer
We do too, actually we even reached out to a Ev boat manufacturer we are in contact with to see if they are going to be using this tech....hope they will.
I drew something similar when I was still in school 20 years ago. It is important not to waste kinetic energy by pushing water sideways. Also most don't consider the acceleration of water along the propeler. Also it's different for open propelers or in a casing... also desired cruise speed and max acceleration dictates which propeler design is the best. For high performance propeling, cavitating and durability of the component is also considered.
I don't really consider this to be all that revolutionary... up until now the private sector was just not really interested in doing anything overly complicated or expensive or adapting the shape to the use case.
@@Berend-ov8of Another option (if aforemention cannot be prevented) would be to limit wasted impulse by putting a second contraption behind the rotor blades rectifying the direction the pushed water flows in (suboptimal, since water/air behind a rotor is subject to whirls and turbulence). Second would be to put something in front of the blades to let the current hit the blades at another angle.
Third would be to encase the blades having a closed propulsion system sideways.
Many such solutions increase the resistance against the current though.
The soluton in the video may be compared to winglets bent into the turning direction of the blades, while directly being prolonged back to the rotor axis to increase durability/sturdyness as well as forming a secondary rotor blade.
Elegant solution in comparison to what other engineers do in the industry.
@@skeltek7487 Yet another solution would be to pull water in from the sides, which is more of an accoustic event. Accoustics is not often intergrated in power design, but in this case it obviously is. Either by chance or on purpose, resulting not only in noticable noise reduction, but also in that increased efficiency.
It does result in a prop with a distinct optimal tune setting, but at that setting, the results are quite surprizing. Plus as a general rule, any activity that isn't there, can't cause damage. I really like this technology. The Sharrow prop is more of a carefully tuned open pump than a prop. Cavitation is expesive. As weird as it may sound, It basically makes water instantaneously boil.
Just look at the thing and imagine the shape of water it creates as it spins.
Compared to that, an ordinary prop looks like the hysterical maid who just saw a mouse.
@@Berend-ov8of Well, a lot of noise is emitted by the pressure fluctuations of water being pushed sideways by the rotor blades whenever one passes that angle and not being pushed when it does not.
'Pulling' water from the sides is problematic, since the maximum speed at which water may flow sideways is limited by the speed of sound in water (not exactly but it correlates to that). The maximum speed at which water could enter a surface area sideways would be limited and cap the maximum performance, while water flowing from the front to the blades would increase linearly proportional with speed.
I agree with the comparison with an open pump, but even there cavitation is possible. I wonder if there will be a high-speed version with slightly different angles in the rotor loops.
" It is important not to waste kinetic energy by pushing water sideways."
Try tell that to a fish.
He'll have a laughin' cramp.
Just occured to me.
@@Berend-ov8of Actually a fish is indeed pushing water backwards mostly. The stream on the side of the body diverts the water to flow antiradially towards the fishs major axis before it reaches its tail fins. The tail fins transform the antiradial motion of water into retrograde motion of the water, which is pretty much antiparallel to the fishs intended direction of movement. Evolution has made fish waste as little energy as possible for those which developed with a focus on speed...
It may look like a fast fish is pushing water mostly sideways, but you got to consider the direction the water flows before and after the tail fin excerts its force...
BUT ? Do these also have the same effeminacy at really low RPM ??
CUZ a big cargo ship the motor top out around 90 - 100 RPM, and i dont think the propeller spin any faster than that.
I am pretty sure Maersk shipping would be all over this if it was making any sense.
One of the main advantages for propellors is, that it would probably last much, much longer. The lack of cavitation, as evidenced by the lack of 'tip' bubble streams, would eliminate one of the greatest dangers to conventional propellors.
Cavitation decreases the efficiency and increases noise.
This I feel is a big point people dont understand of even know.
The benefits of the new designs are sometimes misunderstood. I was unsure about the technology until your video. I was wondering if the toroidal fan shape had been applied to heat pumps. Which to me would be the most obvious place for them.
What about using these for fuel pumps? PR Forced Induction impellers?
That might be very interesting
Brilliant. This change in design needs to be pushed to be adopted purely for the cost savings, let alone the reduction in pollution!
really such a small change for such a huge improvement just stupid
LOL... the prop costs $5000 to make currently... so it wouldn't save you anything in a recreational vessel seeing only occasional use (for that market you need to cost $500-1000 ), it might save you some in a commercial one used daily. Assuming it lasts at least several years of constant use without getting damaged.
@@Wingnut353 true he states they are all custom to the engine driving them as they are fragile and need to be tuned to the stress of the engine torque
if it could save on shipping lanes burn rate that would be great
don't think it is about saving money but about usage efficiency
One thing from being a person that lives by boat and drives a boat to get back and forth from our house to the marina. We end up hitting sticks and small things lots and traditional crops get damaged I wonder how long these would last
i really want to get the raw test data for this propeller, information like motor torque and rpm (power) and thrust produced compared against a control propeller of appropriate size and RPM. its very rare that the efficiency of something is improved by 40% with a new design like this. also with this information missing its difficult to make an informed decision if this propeller is worth the extra $$$
Nice infomercial took me half the video to realize infomercials are back 😂😂
By my calculations at a 46% increase in fuel efficiency and my current boat use I would recover the cost of a Sharow propeller in 12 years.
not great... but not too bad.. at what point would it interest you ? 8 years ? what about the less vibration part does that interest you?
@@TwoBitDaVinci I guess the price will drop in time but yes the reduction in noise would be great.
Just a little nitpick, John Ericsson was not American, he was Swedish.
could you talk about patents and how they reduce the speed of innovation?
Noise reduction is related with efficiency since the energy is dissipated mainly in the form of mechanical vibration (noise) and increase of temperature. A propulsion system that emit less noise is probably more efficient. That happens with electric motors, for example.
Large ships use slow RPM, with slow RPM efficiency torroid propeller doesnt have so much benefits.
the $5000 prop that did your calculation on is for small recreational boats, not that large catamaran you based the calculation on.
Interesting development, not sure why one should cost so much (other than corporate price gouging a 'new and improved' product). I know the Navy has used 'shrouded propulsors' on modern submarines, but obviously there is very little unclassified information about them.
The fact that others had similar designs before without reporting such dramatic improvements leaves me... skeptical. I'll hold onto my money for now, wait and see.
These props have to be machined on a CNC from solid blocks of stainless steel. This is because the shape of the propeller is impossible to cast in a sand mold. Most of a solid block will have to be cut away and recycled, so there's a high material cost. There's some cost recovery from the prime recycle, but its a fraction of the virgin material cost. Additionally, CNC machine time cost increases exponentially with size. Lastly, these are made one at a time and custom order.
Traditional propellers are made by casting the steel into a sand mold and can be made in large batches, dozens or even hundreds at a time.
Not everything is as simple as 'corporate greed'.
@@hawgsrmylife this
Check out the BoatTests review. At cruising RPM, a powerboat was a whopping 11knots faster, 86%, in the middle of the power and, with decreasing returns until it topped out at the same speed as the stock propeller at the maximum RPM. It doesn’t produce as much cavitation so it doesn’t slip like a normal propeller.
And it’s not corporate greed. It’s from small shop in Michigan, they produce all of their propellers in-house with high-end CNC machines, and it’s the only product they make. It’s a bespoke product, and that commands bespoke prices.
@@Neberheim would it be fair to say that, if these were mass manufactured at similar scale to the traditional propellors, then the price would reduce to be in the same price ballpark?
I'm not a mechanical engineer, but as a lowly electrical engineer it strikes me as a bit optimistic the efficiency gains measured with small boats and outboard engines translated to shipping. Small boats typically are planing hull designs and engine and prop speeds in the range of hundreds to thousands RPM. Small improvements in prop design would translate to large efficiency improvement. However, shipping generally use displacement hull and slower engine RPM, by a level of magnitude. I'm not an expert, but guess, the same is true with prop speeds. So my guess would be with lower prop speed, actual prop design would be less critical.
🙋♂️THANKS RICKY…ALREADY WATCHED IT AND I AM IMPRESSED TOO 🤯💚💚💚
Thanks
Could the toroidal propeller concept be applied to variable-pitch propellers? For example, in a wind turbine application, could the blades be replaced by loops? It would not need to be a full loop, just the tip of the blade could be looped to mitigate tip vortices.
Variable pitch props may become obsolete
@@greatcondor8678 I don't see this on petroleum-based airplanes. They run their engines at near to the optimum rotational speed and adjust thrust with variable pitch. Using variable rotational speed to vary the thrust will run the engine(s) in non-fuel efficient speeds. The engine would need to also change to a type that has a much flatter torque curve, like electric motors.
@@greatcondor8678 why do you say that? CPP's still have their benefits which are quite important in the applications that they are most common in.
The same rules would apply to lawnmower blades, fan blades, helicopter blades, and so forth. It makes sense, since you increase the working force by double so the output force would be double.
the BEST propeller is NO propeller , in the FIRST place.
Lawn mower blades are actually a really big deal, if your not cutting efficiency then you might have to cut more often or need a higher powered mower just to get the job done.
@@TwoBitDaVinci I wonder if a more flexible material would improve the idea as well, where applicable. Thinner but stronger metal or even some other kind of material depending on the application- water, air, or organic material... 🤔
Helicopters vary the pitch of their blades asymmetrically to maneuver. To move forward, for example, whatever blade is over the tail experiences the most severe pitch angle. Blade pitch increases to a maximum over the tail and then decreases as the blade moves towards the front. It still produces lift in the front just less than it does while it is in the back. Each blade attaches to a swash plate, which is just a rotary coupling, via pitch control rods. Applying this technology to that kind of mechanism would be a monster challenge. Some sort of elastomeric loop end for each pair of blades? The tail rotor would be easier as all of the blades change pitch in unison. A place to start.
I started that comment intending to say it just wasn't feasible to apply this to helicopters but by the end I started to get ideas. My vote has shifted from no to a slight maybe.
Now this is something that can really help reducing carbon outputs, not to mention improving the impact of motorised vessels on the marine environment. Well done.
yes impacts can be greater that just fuel savings directly
Been looking for a torroidal blade for my wood- burner fan - sadly not found any yet. Need a good simulation software package to optimise the design and 3D print one myself.
Thats a curious idea
Interesting video! Though I wish the units were internationalized, I'm absolutely clueless in freedom units.
Most of the use of numbers was comparisons, that is before and after. In such a case the units are pretty much meaningless anyway. Aside from that, the world over, speed is measured in kts, not Kph or mph but true international units (SI units) would be meters per second... not sure how that really relates to anything useful. And of course US gallons are not gallons but 83%-ish gallons. For all the advances in measurement, we may as well be measuring fuel consumption in furlongs per firkin.
Unable to do simple conversions from Liberian units nor compare percentages - there's a sad statement on folks suffering from innumeracy... I tend to prefer SI units as well, but wow, Siri et al seem to handle that for folks who can't work a calculator.
@@jameswyatt1304 I prefer not that kind of hands-on experience when watching RUclips videos.
I designed one like this ages ago. I really need to follow through on my notebook ideas. Just a muse. Not the fuse.
Another great job!
Thank you! Cheers, I appreciate you!
You're behind the times, the first marine propellor was invented over 100 years earlier by the American invehtor Bushnell for his submarine 'Turtle', built to attack British warships in the War of Independence. The propellors, made in 1775, were powered by hand and worked well, but when he tried to attach an explosive charge to the battleship Eagle, he failed. The reason was that all British warships had copper bottoms, and the auger that Bushnell used to fix the charge could penetrate wood but not copper. The sub was lost the following year when the transport carrying it was sunk. It's still down there somewhere and worth a fortune!
Incredible to get that magnitude of efficiency improvement on such an old technology!
Interesting design but I wonder if that propeller design can handle the intense stresses of larger commercial craft. Big difference in moving a lightweight sport boat and a mega transport cargo ship and you have to consider that many of those cargo ships travel though seas with icebergs etc.
Perhaps just making them bigger and sturdier would suffice?
Awesome that the toroid also makes a built-in safety shroud without adding weight, even more awesome for drone propellers
umm, no. There are still spinning tips and the weight would increase. notice the thickness of the chord on these new props is much thicker than current designs.
@2:15 "video about the discovery of rubber, in the description", but it's not in the description.
Sorry here you go. ruclips.net/video/1w-yDaCN9oo/видео.html
Large ships should have been running on nuclear power for the last 50 years.
Absolutely.
Nuke powerplants are way safer on ships than on land.
Man, between the one stroke cycle and this 105 percent violation of physics, it's going to over-generate it's own fuel. You'll have to stop every few miles to dump fuel out.
My solar electric pontoon boats and the canoe would benefit from the range increase, speed, and load performance. It will need to be a more practical and economical product.
100% ELECTRIC Hydro jet propulsion & MHD is more Efficient.
Mark you keep mentioning this....do you have a favorite example that we should cover?
@@markplott4820 More efficient than what? Electric motors are typically 5 times more efficient than ICE engines, but jet drives are half that of prop efficiency. So how does that play out with all the watercraft types in net-ton-miles per kWh? What does efficiency mean when for entertainment?
I wonder how much of the pricetag on those boat props is the actual more complex manufacturing and how much boils down to intellectual property markup...
Switching to this design would not accommodate constant speed propellers (prop pitch changes instead of engine speed), which means changing over the entire engine system. Not that it would be prohibitive, but it’s not always as simple as swapping out a propeller. Still, it would be amazing for this to take over the industry!
Great point
Don’t believe many large cargo ship have CS props. They are likely designed for a set cruise speed, which is a strong point of these.
the major engineering challenge I see with this is variable pitch control
In aircraft in particular, propeller pitch is changed continuously as the velocity and altitude changes to maintain peak efficiency. with a design like this it will be quite difficult to achieve pitch variation as the entire blade effectively needs to be flexible
also, in regards to DIY 3D printing tests:
3D printer materials are not aerodynamically optimal. like, at all
the finish on a 3D printed item is far rougher than aviation grade manufacturing, so its not really surprising that DIY tests have not found as much of a gain as the researchers
"as the entire blade effectively needs to be flexible"
Exactly !
That will be interesting.
Do a video on district heating with heat pumps. There is a master planned community in Texas that does this. It is more common in Europe and China.
Where is this community?
@@米空軍パイロット /Whisper Valley. It is outside Austin Texas.
@@fortitudethedogwalker6273 Nice. Do they have any other innovative solutions?
JAPAN , has been using HEAT pumps in Residential/small business cooling/heat since 1986 !!!!!
America & EU are OUTDATED.
also since 1986, JAPAN has been using Localized in-home Instant water heaters , located in Kitchen & Bath.
@@markplott4820 We use heat pumps on military bases for cooling and water heating. Basically move heat from the A/C's supply to the hot water tap supply
This is huge for energy efficiency and reducing noise pollution.
Can't wait to see what happens on GA aircraft/prop planes.
I wonder how well a toroidal propeller would work on an electric powered paraglider!?! I like the idea of near silent flight :)
To be able to lecture absolutely accurately about lift/propulsion/drive on a toroidal propeller requires either knowing everything about dynamic lift or nothing at all:
"Axiom concerning the synergy of CIRCULATION and DYNAMIC LIFT:
"Dynamic lift results from the struggle and unity of opposites, the convergence of circulation and lateral Draftflow (1st dialectical law).
Within lateral flow, every object that is circumferentially surrounded, every entity within the universe, regardless of size, weight, shape, or nature, experiences a lateral force - DYNAMIC LIFT.
Dynamic lift is the lateral force that any circumferentially surrounded entity experiences within an additional, lateral flow.
Lateral flow, as indicated by the term 'lateral,' excludes (literally/in the sense of words) a flow direction parallel to the axis of circulation.
The necessary circulation can be
a) aside from its spontaneous generation at an appropriately directed "slanting" angle of airfoil profiles (sails, kite-dragons, wings, turbines, propellers, toroidalpropellers, ship screws, ascending larger, non-spherical air bubbles in liquids) with respect to that lateral flow,
b) a consequent circulation from rotation (akin to falling confetti in a gaseous medium with ensuing friction/interlocking action!)
c) also achieved externally, by switching, controlling, changing direction, and switching direction.
For the purpose of generating the desired lift in a switchable, controllable, and directionally adjustable manner.
Circulation and lift occur within lateral flow either together, interacting or not at all.
This synergistic interplay is only proportional within a very small range. For instance, the KUTTA lift formula (factor times factor times factor equals product) mathematically implies proportionality, but it is limited by the effect of the LAW OF CONSERVATION OF ENERGY to a specific range of validity (alleged "rule of thumb" without explicit justification by the action of the law of conservation of energy.
Lift increase terminates roughly between attaining three and a half to four times the circulation speed relative to the speed of lateral flow, (documented in the letter from the Göttingen wind tunnel operator to the engineer Mr. FLETTNER during the assessment of his rotor intention/invention)."
If quieter this might be a good application for nuclear submarines.
absolutely! great point
And military drones
MHD is the Ticket , Laddie.
I have an even better solution for a submarine that is over 97% efficient...
Could you talk about how we make magnets with an eye toward generating the forces directionally, specifically the opposing forces that allow one to appear to dangle in space. If we can direct this, perhaps we can find the propulsion methodology to get to the stars?
Cut the shipping costs... Lol... More like increase company profits. They wont lower the price they charge.
might be true, I guess its time you start investing in shipping company and push for these props and get in on that sweet profit 🤑
@@TwoBitDaVinci gotta have money first. lol
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Interesting. I notice that all the shown test boats are traveling at planing speed... probably because you would have to be wasting fuel at the rate needed to plane large, heavy, lumps of plastic to make these very pricey blades make sense. I guess being rich enough to afford such toys helps too. One has to wonder how well these would fare against variable pitch props at a speed they are not designed for. How well do they do at displacement speeds? How much resistance do they produce when they are at rest but the boat is moving, for example a sail is being used or a single screw in a double screw vessel is being run. How well do they work in reverse? Another comparison that needs to be made would be to large diameter, slow turning screws such as those used on large freight vessels where tip vortices, while still present, are much lower.
As a side note: The idea they could be used in a helicopter makes no sense as the angle of attack of each blade is different depending on the portion arc the blade is positioned at each microsecond of time. Also, the blades are flexible and rely on centrifugal force to keep them in place so they can be light enough. A solid blade of this new design would have to be very heavy just to hold it's shape and at the same time be able to change its shape continuously over each rotation. Not going to happen. That sounds like patent language trying to cover every possible use of this "invention".
In all, I think these props are great for exactly what they are advertised for, go fast boats with small high rpm props at cruising speed, which to be fair, is where a lot of these kinds of boats spend most of their run time.
To add some info, I've used printed versions of these props on quads and while it is quieter it also puts a larger load on the motors. A 3 bladed version puts almost as much load as a normal 6 bladed prop, not sure how it scales with size yet but the difference from a 6 blade is almost nothing in terms of power use and load. Though it is slightly quieter then a 6 blade
I simply do not understand why, in all of the videos and reports I have seen on the subject of toroidal propellers, I have never seen or heard mentioned that the major difference between the mediums of water and air is that water is non-compressible and air is compressible. This certainly must affect performance.
indeed
They cannot be used for variable pitch applications. Many ships use VP, most propeller aircraft have variable pitch. It would be a boon to heavy shipping as they are huge fuel consumers and harm the ocean environment with the noise.
Add air bubble lubrication and we might have a winning combo