Recently, I had an enlightening experience while using a small electric motor on my boat. I want to share this because it illustrates the significant impact that underwater noises, like those from propellers, can have on marine life. While I was out on the water, something remarkable happened. I switched the motor into reverse, and to my surprise, a seal popped its head up out of the water. Intrigued, I stopped the motor, and the seal submerged. But when I hit reverse again, the seal resurfaced. This wasn't a one-time occurrence. Each time I alternated between forward and reverse, even from a distance, the seal would respond by appearing while the engine was in reverse. This was particularly striking because the motor I was using was very small and relatively quiet - an electric model. Yet, the seal's reaction was immediate and consistent. This interaction, as amazing as it was to witness, really drove home a crucial point for me. It made me realize the profound effect that underwater noise - from things like propellers and even sonar - can have on aquatic creatures. The fact that even a small, 'silent' motor could elicit such a clear response from the seal underscores the sensitivity of marine life to our human-made sounds in their environment. It's an important consideration for all of us who spend time on the water and a reminder of the broader environmental impact of our activities.
@@Grunttamerspecies that do not tolerate loud waterfalls stay away from them. Species that are adapted to be in or near loud waterfals can be found there. What is your point ?
The point about parent whales losing contact with their kids made me think of humans losing their partners at a rock concert - confusion created by 'noise' on the normal signals.
Probably one of THE MOST important data points I've never even heard about! Absolutely remarkable! I've worked in the U.S.Air Force as a Jet Engine Mechanic and can say I NEVER envisioned this but was completely blown away at the context of this idea - coming from Whale fins??!! How mind blowing!
I love to see technology copying biology. I heard another presenter once say, why try to solve it yourself when biology has had the advantage of a billion years or trial an error! Reminds me how important it is to protect the environment, we have so much to learn from it!
@@dougjinks2694 + @AXNJXN1 yes. it has even been given an official scientific name: Biomimicry. "shark skin, with its denticles or scales, is known to reduce drag and increase swimming efficiency for sharks. Applying a similar texture to aircraft skin has been explored as a potential way to reduce drag and improve aerodynamic efficiency." see also, _Lufthansa Technik Aeroshark_ 👍
Never been on a sub, but I played Sub Command, and the fear in the sonarman's voice when you start cavitating is visceral. Makes sense, since short of going active, cavitating is the easiest way to get killed. The voice actor did a good job.
@@sheerluckholmes5468 OP's comment is an English idiom for expressing a large amount/extent of something. For example, if I said, "You have no idea how bad at singing I am," my meaning would be that my singing is of such low quality that it is difficult to fathom. I would not say that phrase to tell you that because you have not heard my singing, you don't have a way to gauge its quality. That would be too literal an interpretation and would simply express an obvious fact.
As a Merchant Mariner, this is really exciting. Always a good day when you learn of a new technology that increases efficiency while ALSO helping the environment. It's a win-win for everyone.
I dunno. Big Auto took away the water engine. Big Energy took away the perpetual motion machine. I expect Big Propeller to take this innovation away from us also.
a patent is holding it back, some one patent it ,but cavitesion go to cero if the propeller is place in front of the ship 🚢 with a pipe running the water back,this design reduce or eliminate the front wave and increase or fill the depression behind the ship, elevating water behind the ship increase propulsion .
More efficiency *and* more thrust. In other words, no performance drawbacks. The issue, of course, is how difficult these things will be to manufacture.
@@jeffbenton6183 Id imagine it would only add 20% more time in manufacturing (Im no expert, but have watched an hour long thing on how they make them). The grinding/sanding part would be the part that would add more time...once the scientific work has been done to verify that it will work as proposes and they have found the most effective way of doing it.
I must say, having used some 3D CAD/CAM drawing programs to design propellers, these are insanely cerebral from the onset. But introduction of tubercles to the edges makes these ever more insanely complex. Your presentation was professionally presented so that anyone could understand this content without struggling. Good job, Ziroth!
the solution is the placement of the propeller, water pump can run 25 years only when air is added to the instake damich appea ,so a tractor propeller because it have a back pressure and a pipe is a solution
Just wanted to make a correction. At 1:57 there's a picture of a propeller that supposedly has cavitation damage. This is actually a picture of a brass propeller that's in the process of being repaired. The outer edges have been welded and the "cavitation damage" is actually the weld that was added to repair the propeller. This will be ground down to match the original shape of the propeller. Thought I'd clear that up incase anyone was confused.
And at 2:05 the computer model of the prop is nonsensical, as the pitch at the tips is greater than the one at the root, while it must be other way around. The prop shown is basically in a "feathered" position.
I first learned about cavitation and its destructiveness as a mechanic working on Caterpillar hydraulic systems; how it would destroy the vane type hydraulic pumps needed to drive the massive rams on Cat scrapers and loaders. Later I learned about the noise issue as it relates to, particularly, submarines and how the U.S. Navy went to extraordinary lengths to keep the design of its submarine props, enshrouded, LITERALLY, in secret and how they could tell exactly where a Soviet submarine was simply by its noise signature. Even now, when you see pictures of U.S. Navy subs in drydock, their propellers are wrapped to keep them hidden from prying eyes. Truly fascinating stuff.
There is a computer fan maker called Noctua from Austria. They have been well known for making quiet fans. If you go their website you will see the same flutes on their fans. This idea came to them more than 20 years ago, after their R&D labs led them to fine tune their observations.
I was going to mention Noctua as well. They have had these shapes on the blades of their fans for many years. Making them widely regarded as the best fans for desktop computers, for how quiet they are, and how much air they can push, buth volume and staic pressure wise.
@@pocketsk3824 Its more likely the difficulty of designing and mass producing these designs that's holding them back. The improvements might not scale with blade speed etc
My homebuilt PC is very quiet. It sits about two feet from me and I can barely hear it. I used Noctua fans for my build. Edit: I should add that the room must be dead quiet for me to even barely hear the fans. Typically, I have no perception of sound from the case.
The bionics researchers at the Technical University of Berlin's group mentioned in the video when the 3D-printed parts were shown actually came up with that concept already in the 1990's. It is specifically based on the work of Dr. Rudolf Bannasch who got it patented back then. German company Blacknoise licensed it and has used it in their Noiseblocker series of PC fans several of which I use and which subjectively considerably outperform other contenders like Noctua and bequiet! in "cleanness" of the noise spectrum. Google for Noiseblocker fans and you'll see they look identical to the large ones in the video.
I've long been interested in nature being the template for human design. As a kid I made clay models of cars and ran water over them to see how the natural flow affected the shape. So I'm fascinated to see this.
I did my dissertation on tubercles, the effect did not seem to be a primary effect of vortex or mixing as would seem intuitive but having a wing with a blend of chord lengths. This in effect smooths the lift/drag distribution so that the wing does not perform as per one specific aerofoil geometry but a blended solution of the chord ranges. This is not so useful for lift generation which can be designed for specified efficient parts of flight but it is useful for maximising the Angles of attack a control surface can be used at - it is not surprising in the end as the humpback whales use the fins for rapid turning and mobility for prey catching, not propulsion.
That sounds similar in concept to the reason for the helical strakes fitted to things like tall chimneys & the lesser known applications like subsea pipelines in order to prevent vortex-induced vibration (VIV). The reason they work is that vibration frequency is a function of diameter (amongst other things) and from any angle, strakes produce a varying effective diameter, which prevents 'lock-in' of the vibration.
That means we've both done real work with these. I was running high AoA and didn't see big effects. Our application was well sorted when we started, so it improve on it would have been tough. We couldn't.
Absolutely brilliant! And, as a spin off, understanding the dynamics of humpback whales was really awesome. I'd never thought how amazing it is that such huge animals propel themselves with such seemingly 'clunky' fins! Phenomenal!
Yes I’m a grammar nazi… “It’s amazing how many designs that we previously thought were so efficient, yet still have the potential for vast improvement.”
Converting 100% rotational energy into linear motion... so makes you wonder what a boat gets. 20%, 30%? Losses from drag on haul in water, wind resistance, thermal... .... I notice the belly of blue whale has strips down the length. Wonder if that helps create some kind of surface laminar flow or something, smoothing out micro surface turbulence. The nose of the blue whale also has bumps, perhaps its a similar situation. Perhaps a perfectly smooth nose cone is not the best solution!!! ... There is an X prize, specifically for solving the turbulence problem. Its got like a million dollar prize. To be able to better define turbulence mathematically is the goal. Basically... golden ratio, log, sinusoidal molecule packing propagation or something. If I knew how to describe it, Id be rich. lol
I've owned boats for years and messed around with different props, they're incredible things the slightest adjustment to the blades size wise makes an enormous difference in slippage and performance, very interesting video a new subscriber gained.
The inner kid in me is so happy to see so much research & testing being done around Biology inspired designs. Then Add in our advancements in material science, engineering, software performance testing methods, etc. I really think we are going to be surprised by what we end up developing. Each development could be unique and useful in different ways. For different tasks and so on. It's just awesome to see so much curiosity and development being combined in this field of productivity.
I actually took part in a research recently regarding the implementation of shark denticles (scales) to surfaces like airfoils to increase efficiency. This was a thesis of my friends and I just tagged along as someone who just happens to know how to design smth like it and can 3D print stuff. They found out that, atleast at higher airflows, there was an increase in efficiency. Excited for them since they'll be going abroad this December for a conference to share their thesis!
The ribbed propeller reminds me of vortex generators on an aircraft wing. The trick to fluid dynamics is balancing the tradeoff between lift/drag/weight and thrust. I love this presentation!❤
I had the same thought, but vortex generators work by mixing more energetic air into a boundary layer that is losing energy and is about to become detached from the airfoil which in turn reduces the thickness of the turbulent wake at the trailing edge of the foil; I'm not sure from the description of the video if this is how tubercles actually work hydrodynamically.
Wing fences, I believe, were devised to control problems with spanwise flow, not so much boundary layer separation. Though like vortex generators did create some extra drag in curing their respective problems.@@allangibson8494
Your U-tube video is layed out beautifully. Your technical information is also very good and brilliant. Your new technical information is excellent. Please keep up the good work.
That's why a golf ball with dimples, travels further compared to a similar size ball with no dimples. It seems rough over smooth appears counter-intuitive, but there is definitely some hidden secrets we can learn from nature.
It's only half right. It's the dimples AND the spin. If your club face hits flat, the ball won't go that far. If you put top spin on one, it will drop even faster. People have even experimented with dimpled rotating dirigible gas sections to add extra lift.
Wrong - Dimples on golf balls create a thin turbulent boundary layer of air that clings to the ball's surface, reducing drag and allowing the ball to travel farther. They also contribute to the lift force, with the spinning action causing higher air pressure on the bottom of the ball than the top, creating an upward force. This combination of reduced drag and increased lift due to the dimples allows a golf ball to travel about twice as far as a smooth ball would. Where as the tubulars being discussed here, redirect the flow of water into narrower channels on the surface of the fin (or blade). Two very different effects.
@@southern_merican ... I'm not saying that it's the case with airplane wings. But there are MANY cases where "we" know of solutions that would be "theoretically better" but that "in practice" are untenable. Either due to economic, production, maintenance or a host of other factors that has to be taken into account when "creating a product for the real world... And I can easily see how "dimpled airplane wings" could be one such a case.
@@EhmedCousCous I think the first jet aircraft flew in like 1939 or something but I don’t know when the first jet engine was built. However, 70 years ago would be 1954. I was just trying to make a joke, but the point of the joke is more like we’ve moved on from prop planes for a very long time and now we’re just finally figuring out how to make a good prop.
@@leudast1215 a turbine can be multiple devices, but essentially they would all be a spinning mechanism with multiple fan blades used to produce force from a fluid I believe. And I know you think you did something here but you didn’t because the turbine jet engine could work even better if it had better blades or what you mistakenly consider props.
@@EhmedCousCous 2024-70 = 1954... Jet engines were invented around the beginning of WW2 but were too unreliable then. The first jet aircraft built in series was the Me-262 which was put in service in 1944, and jet engines became widespread in the 50s and 60s.
Just as a short side note. The 2 propellers shown use completely different concepts. One is a (water) propeller with structure on the leading edge, the other is a shrouded propeller with structure on the tailing edge. First one is probably good for slow moving air/water the other for fast moving air. Latter is also based on the concept of an owls wing to reduce noise and is already in wide spread use especially in noise reduced ventilation of factory floors (and PCs)
With the Jesus lizard prop, that looks a lot like a voith-schneider turned on its side, you should check those out! They're not super common, but sometimes used in ships where a lot of thrust is needed in all directions, like tugboats. ABB recently unveiled the Dynafin that was inspired by whale fins, or so their marketing dept claims lol Also I have a soft spot for super-cavitating props or chop props, which is an interesting way to work around the cavitation issue. They're basically only used in race boats because they're only efficient at very high speed
Similarly so in fast boats, the bottoms are NOT polished, they are usually roughened with 180-220 grit sandpaper to prevent micro Eddy's from sucking the hull to the water.
7:26 As a person who is flying RC gliders in competition , i experimented a lot about wingfoils and with zigzag tapes etc to make the air stick better and longer to the profile... Around 20y ago, when i started it, i was thinking why propellers werent like that.... i saw the wide use for it back then already .. Discussed it a lot with friends
And they would all have said it wasn't the thing to do, many years ago at the infancy of RC helicopters (no epicyclic, all off the throttle and often lots of bits on "landing"), I inquire about twin rotor helicopters like the Belvedere, (bit of a favourite), it was explained to me with all the aerodynamic reasons why at scale it would not work, come forward nigh on fifty years and you can buy indoor twin rotor craft at most good model sbops. We have had over two hundred years of what propellers should look like so this will take a lot of persuading to get people to accept it, no matter how good, and the only thing that will push it is the bottom line, how much money it can save, unfortunately sad but true.
@@CrusaderSports250 a good example of thinking outside "the box" is the tunnel like wings. They proof that we have to open up our brains that ANYTHING can work,we only need to invent it
If these were first tested in 2008 with positive results, why hasn’t extra R&D taken place by the major manufacturers of props? The whale being a slow mover has no cavitation to overcome so I find it unlikely it’d be much help with that, an owl on the other hand can fly stealthily with modified feather placement, but with the fluid viscosity being so different, it won’t work in water.
In my opinion even if it gives small gains in thrust for the boats it might be not profitable from manufacturing perspective. Making this kind of pattern in the stainless steel might not be an easy task. I can imagine it being first introduced in the small scale or in computer fan propellers. Of course if this gives any profits to air flow and acts well in high rpm conditions. Another aspect is if anyone has a patent for that.
No it was not tested first in 2008. WAY WAY before this. Decades before this. He needs to do more research. I read a paper as old as 1930's on it. So, it was probably done before then as well. Got me. Most ideas require a lot of $$$ to implement in a mass produced product to change industries.
Nature paper says "Our findings present a possible avenue for mitigating cavitation erosion through the application of inexpensive and environmentally friendly materials." It kind of seemed like you were saying GEMS would help mitigate the sound of the propellors and engines, but GEMS allow for louder propellors because the surface coating reduces cavitation damage and not cavitation itself, in theory allowing for faster and louder propellors.
If you want to talk about advancements in prop design, you might have mentioned the Sharrow prop. Totally different design, uses a third less fuel and produces more power. Used mainly for outboards but i don't see why the wouldn't work on a larger cruising boat.
I became aware of the 'tubercle effect' at _least_ 10 years ago. I'm a a bit surprised it hasn't been adapted to say room fans, as IIRC it moved 50%(?) more air using 20% less energy and was quieter than 'normal' fan blades.
So maybe it isn't quite as incredible in application. PC fans have had serrated trailing edges for 20 something years though so maybe in that small of an application in a fluid as thin as air it works to reduce noise
I learned about cavitation bubbles while watching vids about steam ocean liners. If a propeller was not made properly, it can cause serious vibrations throughout the ship, and make it uncomfortable for the passengers. Interesting to see this kind of innovation, sure don't want to stick your finger in a fan that has teeth though.
Wow, this video was super informative and entertaining! I’m a new member, and I just wanted to share something. Being next to a wind turbine isn’t bothering me at all. The slow-moving, huge wings make a low, almost humming noise that’s so soothing. I have relatives who live pretty close to a turbine, and in the summer, it’s like having a natural lullaby. It’s the best! Get some fresh air and enjoy that humming noise that lets me sleep for hours. Cheers!
Pretty sure I've occasionally seen such ridged blades used in PC cooling fans for at least a decade now. They pop up now and then when a manufacturer claims a new breakthrough (as they do with every single new fan), and then the next generation after that goes back to being straight-bladed.
Have you looked at the duo prop? Volvo-Penta introduced the idea a number of years ago, 2 props on the same drive shaft, turning in opposite directions. I can't remember the specific numbers but these props gave significantly better performance. Best of all, they backed it up with production. The Volvo-Penta IPS drive for motor yachts comes with duo-props.
I am not familiar with maritime applications. In aviation however,just before the jet age took over, aircraft such as the F4U,P47,P51,Seafire FR-47,were built with contra-rotating propellers. 2 three bladed props. YT has a great video of the only airworthy Seafire FR-47. The Seafire FR-47,a Spitfire variant,used this design to neutralize the torque effect of the engine, so as to utilize more power on take off from aircraft carriers. Contra rotating- opposite rotation,same axis Counter rotating-opposite rotation,different axis (P-38) Cheers
Another interesting propeller design since you asked is one I saw where instead of contra rotating props one of them is essentially a stator, ie fixed, which has produced surprising and promising performance improvements.
What's surprising about thar? Counter rotatimg.props are not used because of their crazy noise levels giving you no access to civilan airports. Russian military does use them on some models. Some militarry argo planes use them as well. The bypass mass flow ratio is way higher.
@@voster77hh There are some claims out there, that a lot of the Counter rotating prop noise can be avoided, if you have a different number of blades on prop 1 and 2. Makes sense to me, but I'm not an expert.
When I was a kid growing up on the St Lawrence River we could hear lakers coming from a few miles away easily. Those big single engine lakers sounded like a rythmic bump bump bump sound if your head was underwater.
What would be the benefits if the bionic shape would be implemented on a toroidal propeller? I would be very interested to see some test and what is improved or not with such a propeller :D
Cavitation is extremely loud! I was in a ferry. The mechanic took me to see the engine room. He was extremely kind and informative. Then a horrible banging and rumble started very suddenly. It felt like the ship had bottomed out. The mechanic said, "cavitation! We just changed that propeller! I'll be back!" He took off running screaming into a walkie talking about what was going on. I do not know why he was so upset. I did not want to anger the mechanic, so did not ask. He came back a few minutes after things smoothened out and apologised. He was not happy at the operation of the ship. But, I never asked him what issues could arise from the cavitation. This video answered the question.
I came up with a biomimetic propeller design back in 1997 or 1989 while working at Arcturus Marine Systems. I even have a "poor man's patent" of the idea - I mailed drawings and notes of the concept/design to myself in a stamped and sealed envelope. I even put an extra postal stamp on the back of the flap and had it canceled manually before I mailed it to myself, I still have that sitting in my fire safe.
Additive manufacturing at home is going to revolutionize many things. I'm already picturing how easily multiple variations can be produced and tested using plastics, before anything is committed to casts or die molds for metals. 👏
Mother nature also doesn't spin at thousands of RPM's. Not all the comparisons made are valid, but we definitely can learn a lot from nature! We live in a really interesting age!
Thank 🐢 you. Years ago when working on a ruff' sandy beach we 'toar up' the prop and noticed reduced vibration and cavitation. And as a kid I noticed the wind trails during foggy weather were smoother from fence pickets with weathered tops.
I'm wondering if the US Navy already knows about this....and has gone WAY beyond. They cover the propellers of the submarines. Would be interesting to know what they look like.
I've owned a long string of boats since the age of 16 - 63 years ago. Little boats at first then bigger and bigger boats. I learned about cavitation with my first ski boat. I never gave much thought to it just adjusted the boat to the point where it was most effective. I read about these propeller designs earlier but your information about the whale was very interesting. Manufacturing cost and variability are the prohibitive constraints right now. I think the manufacturing issues will be worked out over time but they will still be costly. The same considerations have been used in wing design for some time. As to creative design, it is what human kind does. One building block at a time, each one enhancing what was done before. Every now and then something new will come along but even in that regard there is most often a history of development. Even some of Einstein's thinking was based on the creative thinking of other individuals. Good report.
So can these shapes and their effects also be applied to toroidal propellers? Because toroidal propellers seem to already be more effective compared to traditional and traditional with these modifications, so are we able to mix the two ideas in a way where we gain even more effectiveness in the toroidal performance for efficiency and sound reduction?
What about using golf ball dimples on propellers like was done on Mythbusters to improve MPG on a vehicle? Add that to the whale design then see if that does anything more for efficiency and noise reduction.
Completely forgot about golf balls, I was so deep into the tubercles research! This is definitely interesting, I'll get digging and see if there is more interesting things to learn on the topic of dimples
Wow man! Good Stuff! I'll be sharing this link. It is not just the propellers that grabbed me, but its resemblance to the strakes that reduce the drag of wind and fluids on towers in storms. I bet we see a tie-in as research continues. Thanks for the show!
He clearly tfk says biomimetic wtfk planet are ya on pretty sure it pertains to the prop surface at least in the context that its used in the above video so biomimetic by definition describes relation of prop surface fkn texture as it has relitave effect speeding through water strictly upon cavitation or how it affects prop surface when prop encounters cavitation mainly not fkn destroying the prop using mushroom shaped wtfk ever jfc I didn't graduate 7th grade but even then it's pretty clear like water clear if the listener enjoys entire video or is able to retain attention span of a minute plus lmao. And yes, the apparent lack of punctuation and run on sentences deffinatly proves that 7th grade drop out knowledge!!!!! Lol
I’m glad they don’t. I hate the metric system. So many writers use it wrong. I once read a story involving a crew member of a space ship being a few centimeters taller than her fellow crew members, described as “towering over them.” Intrigued, and not being very well versed in the metric system, I used a formula to convert it to the standard English system and it turned out that the few centimeters converted to two or three inches. Towered over the others, indeed. If two or three inches is towering over others, then being 5 feet 10 inches tall, I must be a giant. 😅😊
Just a simple observation. I was flying a custom home built 30" span rc model with a standerd 6x4x2 blade prop. It behaved like an underpowered aircraft literally hanging on the prop and quickly went down in a farmers field. I recovered the plane and noted the leading edges of the prop were seriously scuffed up as though a sand blaster had hit it. Not having a replacement blade handy, I launched it again. The result was a dramatic performance improvement in speed. However, noise was much greater. The only change I could attribute this to was the blades leading edge.
I have an old prop that’s washed out. Meaning run so much the water grooved the blades. They look just like the bionic prop. Nature was telling me. I just wasn’t looking. In fact, until this video I never gave it a second thought. Thanks man 😊
Natures has had the blueprint from the start, we just needed time to understand how we can work with it. Hopefully a brighter future and deeper respect for nature as we advance as a species
Hydroelectric generator turbine blades may also benefit from these design improvements if they provide a meaningful efficiency increase and reduce cavitation damage. Mother Nature is a great teacher. Thanks for the video.
Thank you for a clear explanation of a subject most do not have a lot of knowledge of. The answer of every question humankind has is in nature, if we take the time to find them.
In 2006, I worked with one of Dr. Fish's grad students to build a tubercle wing for a race car. We had a 40% model made and ran a full day in a wind tunnel (AAR in Santa Ana, CA) to test. There were some effects, but they were very, very small. We often run stalled or near stalled and in that situation, it just wasn't much of an effect. We were hoping for the best and stuck about $50k into the project, but we never got anything out of it. We know that at least one Formula 1 team investigated the idea and I never saw it on their car. The student was from Cal Tech. He was brilliant, but we ended up parting poorly when he started trying to claim results that the data just did not support. I was really disappointed that a PhD, from Cal Tech no less, would stoop to this level. I'm in racing; bullshit get called early and aggressively. As I've gotten older, I've come to think he was just a product of the institution which he was trained, as we've seen many from prestigious schools will do the same thing.
Hi. The small insects that "walk on water" rely on surface tension. Water forms a "meniscus" because its molecule is polarized. This is why the flat surface of your cup-of-tea curves upwards where it joins the sides of your cup. It can curve downwards too if the sides of your cup are dry. Nice video, thanks. P.R.
When we returned from our honeymoon, we stopped at the Albacore museum. There was a vessel on display with an experimental "cavitation drive" - two nacelles supported the main body, with the propellers at the front. The idea was that cavitation would lower the resistance of the nacelles. Supposedly it did about 60 knots.
This channel reminds me of “The Shark’s Paintbrush” suggesting wall paint that mimics pond dwelling lily pads that float partially because they’re designed by nature to let water run effortlessly off them promoting buoyancy. You sir are Not all talk. You actually are making a difference. Your friends remind me of Jacques Cousteau. Thank you for the effort and well done indeed sir.
Brilliant. Biomemetics is still in its infancy and already shows great promise. But what about the strange propulsion dynamics of squids and octopuses? If there were staggered systems, it would even eliminate the surge and slowing effect.
It’s actually kind of impressive that no-one have though of it long before, plus there are likely hundreds of thousands of other things we can improve by mimicking nature.
Traditional propellers used in marine and air transportation have two major problems - cavitation and excess drag. Cavitation happens when the pressure on the low-pressure suction side of the blades drops, causing water to vaporize and small vapor-filled bubbles form. These bubbles erode the blades, reduce efficiency, and create noise. Excess drag is caused by the angle of attack between the blade's edges and the direction of the oncoming fluid. Managing these two problems is essential to improving propeller efficiency, which is critical for reducing noise pollution that affects marine animals and aircraft passengers. Biometric solutions inspired by nature are transforming propeller design. For example, 3D printed propellers based on the tubercles of humpback whales, which reduce drag and improve maneuverability, have been tested with promising results. Propellers inspired by the flippers of penguins and the scales of sharks have also been developed to improve efficiency. These biomimetic designs could reduce noise pollution and improve efficiency, which is essential for sustainable transportation and protecting endangered animals.
My background is that of an unlimited ton captain, seeing the toroidal propeller had me thinking about if it could pay for itself by the time it was past its service life. Took in factors such as increased fuel efficiency, better thrust, and less wear and tear on the propulsion system. At the time a started calculating, it unfortunately did not pay for itself. This is in regard to the 45” diameter bronze alloy prop i need to use. I also need 2. These bionic propellors have me excited. I need to research the price or a quote but i know they will be a fraction of the cost of a toroidal prop. Not a ton of published testing for the bionic prop but as soon as their is enough info, im hoping the gains can pay for the bionic prop or even start to make me a profit
I've heard noisy propeller planes fly around and I've heard them long before I saw them. I can't imagine being underwater and seeing the wake of a speed boat sailing around. I also LOVE biomimetics. Nature uses fractals, we use them. Winglets in commercial aircraft, we copied wingtips in birds. Velcro come from hitchhikerseeds. Syringes started to copy mosquito needles.
I tried to share this with an airplane propeller manufacturer . He was quick to slam the door shut as nonsense. Glad we are working on proofs and measurements. It’s about time! Thank god….Who invented the bump propeller! 😊
As a youth I love ved fast boats, extremely fast boats. I learned from John McCall, inventor of the tear away cowl in race boats was also an expert on props, he'd get as much pitch as possible then cup to tune, running wheels he built required the prop to be a tad over halfway out of the water in line with the planning surface. Also a modified V with a very small planning surface helps as well. Performance wise, they were dogs out of the hole, (to get on plane) but once the prop bit, it'd set you back in your seat hard and the howl the prop made, could be heard from Sarasota Bay to the Venice Inlet (Jetty's) the boat went from a 50 mph boat, with Factory sized prop and a 75 3 cylinder on 14' boat (Allison, factory Built Race Boat) to 75+ A few buddies and myself, all working class fellows had to compete with the Billionaires across the intracoastal waterway who'd buy the best they could find but they couldn't buy the wisdom of John McCall RIP
Feathered propellors are like owl (silent) wings - with little or no cavitation or air bubbles. Using front-end feathering, and/or back-end feathering diminishes cavitation, but also diminises water surface drag. Like the same that should be used with helicopter blades (and the thunk, thunk, thunk sound) you need to use the same upturned wind tip, shooting the sound of the propellor upward and away from equal or underneath viewers/listeners. Also feathering the back end of wings also silences the wings, but also stop further air drag and noise. Water propellers outward edge (like the torroid propellor) having a feathered edge further silences any vibration, engine combustion explosion and bearings noise passing into the propellor into the water.
Manatees in Florida suffer horrific injuries from boat propellers. Simply adding an external ring would be a huge improvement. Making a more efficient propeller makes it a no brainier.
I was thinking same thing but you want lift created by the low pressure above the propeller so I am not so sure. Do drones get lift from the prop or is it mostly just pushing air down?
Recently, I had an enlightening experience while using a small electric motor on my boat. I want to share this because it illustrates the significant impact that underwater noises, like those from propellers, can have on marine life.
While I was out on the water, something remarkable happened. I switched the motor into reverse, and to my surprise, a seal popped its head up out of the water. Intrigued, I stopped the motor, and the seal submerged. But when I hit reverse again, the seal resurfaced. This wasn't a one-time occurrence. Each time I alternated between forward and reverse, even from a distance, the seal would respond by appearing while the engine was in reverse.
This was particularly striking because the motor I was using was very small and relatively quiet - an electric model. Yet, the seal's reaction was immediate and consistent. This interaction, as amazing as it was to witness, really drove home a crucial point for me.
It made me realize the profound effect that underwater noise - from things like propellers and even sonar - can have on aquatic creatures. The fact that even a small, 'silent' motor could elicit such a clear response from the seal underscores the sensitivity of marine life to our human-made sounds in their environment. It's an important consideration for all of us who spend time on the water and a reminder of the broader environmental impact of our activities.
Reverse psychology
If this was the case then aquatic animals would avoid loud natural sounds also. Is there any evidence of wildlife behaving similarly near waterfalls?
@@Grunttamerspecies that do not tolerate loud waterfalls stay away from them. Species that are adapted to be in or near loud waterfals can be found there. What is your point ?
Sound speed is 4X the speed underwater ✔️
The point about parent whales losing contact with their kids made me think of humans losing their partners at a rock concert - confusion created by 'noise' on the normal signals.
Probably one of THE MOST important data points I've never even heard about! Absolutely remarkable! I've worked in the U.S.Air Force as a Jet Engine Mechanic and can say I NEVER envisioned this but was completely blown away at the context of this idea - coming from Whale fins??!! How mind blowing!
I love to see technology copying biology. I heard another presenter once say, why try to solve it yourself when biology has had the advantage of a billion years or trial an error! Reminds me how important it is to protect the environment, we have so much to learn from it!
@@dougjinks2694 + @AXNJXN1
yes. it has even been given an official scientific name: Biomimicry.
"shark skin, with its denticles or scales, is known to reduce drag
and increase swimming efficiency for sharks.
Applying a similar texture to aircraft skin has been explored
as a potential way to reduce drag and improve aerodynamic efficiency."
see also, _Lufthansa Technik Aeroshark_ 👍
Is this really all that recent though? I could swear I've been seeing those wavy blade shapes in CPU coolers for years now.
As a former submarine sonar tech you have no idea how terrified of cavitation I am 😂
Never been on a sub, but I played Sub Command, and the fear in the sonarman's voice when you start cavitating is visceral.
Makes sense, since short of going active, cavitating is the easiest way to get killed. The voice actor did a good job.
Cavitation in an underwater stealthy vehicle should be like blaring a loudspeaker saying, "Here I am! Shoot at me!"
"former" 😏
Yeah, you got me on that one, as I too have no idea of how terrified you were of cavitation.
@@sheerluckholmes5468 OP's comment is an English idiom for expressing a large amount/extent of something. For example, if I said, "You have no idea how bad at singing I am," my meaning would be that my singing is of such low quality that it is difficult to fathom. I would not say that phrase to tell you that because you have not heard my singing, you don't have a way to gauge its quality. That would be too literal an interpretation and would simply express an obvious fact.
As a Merchant Mariner, this is really exciting. Always a good day when you learn of a new technology that increases efficiency while ALSO helping the environment. It's a win-win for everyone.
I dunno. Big Auto took away the water engine. Big Energy took away the perpetual motion machine.
I expect Big Propeller to take this innovation away from us also.
a patent is holding it back, some one patent it ,but cavitesion go to cero if the propeller is place in front of the ship 🚢 with a pipe running the water back,this design reduce or eliminate the front wave and increase or fill the depression behind the ship, elevating water behind the ship increase propulsion .
More efficiency *and* more thrust. In other words, no performance drawbacks. The issue, of course, is how difficult these things will be to manufacture.
@@jeffbenton6183 Id imagine it would only add 20% more time in manufacturing (Im no expert, but have watched an hour long thing on how they make them). The grinding/sanding part would be the part that would add more time...once the scientific work has been done to verify that it will work as proposes and they have found the most effective way of doing it.
Marine Biologist Frank Fish? You cannot make this up!
Nominative Determinism
I worked with an Dr of biology specializing in avian biology named Dr Bird...
The sea was angry that day
@@vcprado- like an old man handing back soup at a deli.
Inventor of the toilet?
Thomas Crapper.
I must say, having used some 3D CAD/CAM drawing programs to design propellers, these are insanely cerebral from the onset. But introduction of tubercles to the edges makes these ever more insanely complex. Your presentation was professionally presented so that anyone could understand this content without struggling. Good job, Ziroth!
the solution is the placement of the propeller, water pump can run 25 years only when air is added to the instake damich appea
,so a tractor propeller because it have a back pressure and a pipe is a solution
Just wanted to make a correction. At 1:57 there's a picture of a propeller that supposedly has cavitation damage. This is actually a picture of a brass propeller that's in the process of being repaired. The outer edges have been welded and the "cavitation damage" is actually the weld that was added to repair the propeller. This will be ground down to match the original shape of the propeller. Thought I'd clear that up incase anyone was confused.
And at 2:05 the computer model of the prop is nonsensical, as the pitch at the tips is greater than the one at the root, while it must be other way around. The prop shown is basically in a "feathered" position.
thought it was weird how the cavitation which "eats away" at the prop somehow managed to add material to it
Better pic at 2:27.
Engineer here - I wondered about that.
Thanks for clearing it up.
It is even easy to see the heat-affected zones from the welding.
The guy making this video lacks quite a lot of engineering knowledge I guess..
I first learned about cavitation and its destructiveness as a mechanic working on Caterpillar hydraulic systems; how it would destroy the vane type hydraulic pumps needed to drive the massive rams on Cat scrapers and loaders. Later I learned about the noise issue as it relates to, particularly, submarines and how the U.S. Navy went to extraordinary lengths to keep the design of its submarine props, enshrouded, LITERALLY, in secret and how they could tell exactly where a Soviet submarine was simply by its noise signature. Even now, when you see pictures of U.S. Navy subs in drydock, their propellers are wrapped to keep them hidden from prying eyes. Truly fascinating stuff.
There is a computer fan maker called Noctua from Austria. They have been well known for making quiet fans. If you go their website you will see the same flutes on their fans. This idea came to them more than 20 years ago, after their R&D labs led them to fine tune their observations.
I'm a big fan of noctua!
I was going to mention Noctua as well. They have had these shapes on the blades of their fans for many years. Making them widely regarded as the best fans for desktop computers, for how quiet they are, and how much air they can push, buth volume and staic pressure wise.
@@pocketsk3824 Its more likely the difficulty of designing and mass producing these designs that's holding them back. The improvements might not scale with blade speed etc
My homebuilt PC is very quiet. It sits about two feet from me and I can barely hear it. I used Noctua fans for my build.
Edit: I should add that the room must be dead quiet for me to even barely hear the fans. Typically, I have no perception of sound from the case.
The bionics researchers at the Technical University of Berlin's group mentioned in the video when the 3D-printed parts were shown actually came up with that concept already in the 1990's. It is specifically based on the work of Dr. Rudolf Bannasch who got it patented back then. German company Blacknoise licensed it and has used it in their Noiseblocker series of PC fans several of which I use and which subjectively considerably outperform other contenders like Noctua and bequiet! in "cleanness" of the noise spectrum. Google for Noiseblocker fans and you'll see they look identical to the large ones in the video.
I've long been interested in nature being the template for human design. As a kid I made clay models of cars and ran water over them to see how the natural flow affected the shape. So I'm fascinated to see this.
That's why they are better off playing outside...
I did my dissertation on tubercles, the effect did not seem to be a primary effect of vortex or mixing as would seem intuitive but having a wing with a blend of chord lengths. This in effect smooths the lift/drag distribution so that the wing does not perform as per one specific aerofoil geometry but a blended solution of the chord ranges. This is not so useful for lift generation which can be designed for specified efficient parts of flight but it is useful for maximising the Angles of attack a control surface can be used at - it is not surprising in the end as the humpback whales use the fins for rapid turning and mobility for prey catching, not propulsion.
The paper I read they reduced drag from reducing cavitation
That's really cool. Is your dissertation uploaded somewhere?
So they are like fingers?
That sounds similar in concept to the reason for the helical strakes fitted to things like tall chimneys & the lesser known applications like subsea pipelines in order to prevent vortex-induced vibration (VIV). The reason they work is that vibration frequency is a function of diameter (amongst other things) and from any angle, strakes produce a varying effective diameter, which prevents 'lock-in' of the vibration.
That means we've both done real work with these. I was running high AoA and didn't see big effects. Our application was well sorted when we started, so it improve on it would have been tough. We couldn't.
Absolutely brilliant! And, as a spin off, understanding the dynamics of humpback whales was really awesome. I'd never thought how amazing it is that such huge animals propel themselves with such seemingly 'clunky' fins! Phenomenal!
Yeah me too
amazing how many designs that we previously thought were so efficient, have still so much to be bettered.
Bettered?
Improvered
@@alanESV2Improved
Yes I’m a grammar nazi…
“It’s amazing how many designs that we previously thought were so efficient, yet still have the potential for vast improvement.”
Converting 100% rotational energy into linear motion... so makes you wonder what a boat gets. 20%, 30%?
Losses from drag on haul in water, wind resistance, thermal...
....
I notice the belly of blue whale has strips down the length. Wonder if that helps create some kind of surface laminar flow or something, smoothing out micro surface turbulence. The nose of the blue whale also has bumps, perhaps its a similar situation. Perhaps a perfectly smooth nose cone is not the best solution!!!
...
There is an X prize, specifically for solving the turbulence problem. Its got like a million dollar prize. To be able to better define turbulence mathematically is the goal.
Basically... golden ratio, log, sinusoidal molecule packing propagation or something. If I knew how to describe it, Id be rich. lol
I've owned boats for years and messed around with different props, they're incredible things the slightest adjustment to the blades size wise makes an enormous difference in slippage and performance, very interesting video a new subscriber gained.
The inner kid in me is so happy to see so much research & testing being done around Biology inspired designs. Then Add in our advancements in material science, engineering, software performance testing methods, etc. I really think we are going to be surprised by what we end up developing. Each development could be unique and useful in different ways. For different tasks and so on. It's just awesome to see so much curiosity and development being combined in this field of productivity.
Couldn't agree more!
I actually took part in a research recently regarding the implementation of shark denticles (scales) to surfaces like airfoils to increase efficiency. This was a thesis of my friends and I just tagged along as someone who just happens to know how to design smth like it and can 3D print stuff. They found out that, atleast at higher airflows, there was an increase in efficiency. Excited for them since they'll be going abroad this December for a conference to share their thesis!
That's likely because air operates more like a fluid at higher speeds
The ribbed propeller reminds me of vortex generators on an aircraft wing. The trick to fluid dynamics is balancing the tradeoff between lift/drag/weight and thrust. I love this presentation!❤
Same, vortex generators!
I had the same thought, but vortex generators work by mixing more energetic air into a boundary layer that is losing energy and is about to become detached from the airfoil which in turn reduces the thickness of the turbulent wake at the trailing edge of the foil; I'm not sure from the description of the video if this is how tubercles actually work hydrodynamically.
The shape also reminds me of chevrons at the edge of turbofan nozzles; another noise reducing technique.
Or wing fences. Very common on airliner wings since the 1950’s.
Wing fences, I believe, were devised to control problems with spanwise flow, not so much boundary layer separation. Though like vortex generators did create some extra drag in curing their respective problems.@@allangibson8494
Would be nice to see a toroidal-bionical propeller eficiency test results!
you're teaching me about so many types of propellors, literally couldn't think of the type of designs... amazing what innovation can do, thanks! :)
Your U-tube video is layed out beautifully. Your technical information is also very good and brilliant. Your new technical information is excellent. Please keep up the good work.
That's why a golf ball with dimples, travels further compared to a similar size ball with no dimples. It seems rough over smooth appears counter-intuitive, but there is definitely some hidden secrets we can learn from nature.
Wow you wrote the first comment on youtube that is actually right about the "golfball" effect. Congrats.
I wonder why planes don't have dimples on one side or maybe both sides
It's only half right. It's the dimples AND the spin. If your club face hits flat, the ball won't go that far. If you put top spin on one, it will drop even faster. People have even experimented with dimpled rotating dirigible gas sections to add extra lift.
Wrong - Dimples on golf balls create a thin turbulent boundary layer of air that clings to the ball's surface, reducing drag and allowing the ball to travel farther. They also contribute to the lift force, with the spinning action causing higher air pressure on the bottom of the ball than the top, creating an upward force. This combination of reduced drag and increased lift due to the dimples allows a golf ball to travel about twice as far as a smooth ball would. Where as the tubulars being discussed here, redirect the flow of water into narrower channels on the surface of the fin (or blade). Two very different effects.
@@southern_merican ... I'm not saying that it's the case with airplane wings. But there are MANY cases where "we" know of solutions that would be "theoretically better" but that "in practice" are untenable. Either due to economic, production, maintenance or a host of other factors that has to be taken into account when "creating a product for the real world...
And I can easily see how "dimpled airplane wings" could be one such a case.
Crazy to think that we're 70 years into the jet age and we're just now starting to figure out how to make a good propellers awesome video
Jet engine was invented in the 1920s?
@@EhmedCousCous I think the first jet aircraft flew in like 1939 or something but I don’t know when the first jet engine was built. However, 70 years ago would be 1954. I was just trying to make a joke, but the point of the joke is more like we’ve moved on from prop planes for a very long time and now we’re just finally figuring out how to make a good prop.
What do you turbines are? We never moved past propellers @TomisaLami
@@leudast1215 a turbine can be multiple devices, but essentially they would all be a spinning mechanism with multiple fan blades used to produce force from a fluid I believe.
And I know you think you did something here but you didn’t because the turbine jet engine could work even better if it had better blades or what you mistakenly consider props.
@@EhmedCousCous 2024-70 = 1954...
Jet engines were invented around the beginning of WW2 but were too unreliable then. The first jet aircraft built in series was the Me-262 which was put in service in 1944, and jet engines became widespread in the 50s and 60s.
Just as a short side note. The 2 propellers shown use completely different concepts. One is a (water) propeller with structure on the leading edge, the other is a shrouded propeller with structure on the tailing edge. First one is probably good for slow moving air/water the other for fast moving air. Latter is also based on the concept of an owls wing to reduce noise and is already in wide spread use especially in noise reduced ventilation of factory floors (and PCs)
Nature is our best teacher. Millions of years of intense evolutionary engineering work that had proven successful.
they can become trapped in a local minimum though.
With the Jesus lizard prop, that looks a lot like a voith-schneider turned on its side, you should check those out! They're not super common, but sometimes used in ships where a lot of thrust is needed in all directions, like tugboats. ABB recently unveiled the Dynafin that was inspired by whale fins, or so their marketing dept claims lol
Also I have a soft spot for super-cavitating props or chop props, which is an interesting way to work around the cavitation issue. They're basically only used in race boats because they're only efficient at very high speed
This looks like a good rabbit hole for me to start going down! Cheers 😀
@@ZirothTech Awesome! There's a lot of really cool tech in the offshore and maritime industry, happy to see it getting attention!
Googled Dynafin, very interesting!
Fascinating! Excellent presentation, RUclips needs quality content like this very badly now. Subscribed.
Similarly so in fast boats, the bottoms are NOT polished, they are usually roughened with 180-220 grit sandpaper to prevent micro Eddy's from sucking the hull to the water.
Sharkskin is likewise rough and reduces drag.
think golfballs . dimples work😊
Like golf balls that have dimples?
@@TheFrewahyes
I love it when I find a new channel that is as well produced and researched as this one. New subscriber here, this was fascinating!
Thanks for the kind words!
7:26 As a person who is flying RC gliders in competition , i experimented a lot about wingfoils and with zigzag tapes etc to make the air stick better and longer to the profile...
Around 20y ago, when i started it, i was thinking why propellers werent like that.... i saw the wide use for it back then already ..
Discussed it a lot with friends
And they would all have said it wasn't the thing to do, many years ago at the infancy of RC helicopters (no epicyclic, all off the throttle and often lots of bits on "landing"), I inquire about twin rotor helicopters like the Belvedere, (bit of a favourite), it was explained to me with all the aerodynamic reasons why at scale it would not work, come forward nigh on fifty years and you can buy indoor twin rotor craft at most good model sbops. We have had over two hundred years of what propellers should look like so this will take a lot of persuading to get people to accept it, no matter how good, and the only thing that will push it is the bottom line, how much money it can save, unfortunately sad but true.
@@CrusaderSports250 back then i said, if everybody was thinking like that negative, we wouldnt be flying today!
@jasmijnariel very true but getting over what is considered the way things work can be very difficult especially if you are also looking for funding.
@@CrusaderSports250 a good example of thinking outside "the box" is the tunnel like wings. They proof that we have to open up our brains that ANYTHING can work,we only need to invent it
Didn't the concept for the winglets we now see on commercial planes come from an RC model plane builder!!???
It is amazing how nature has such specific complex designs for us to copy, almost like nature itself was made by design!
If these were first tested in 2008 with positive results, why hasn’t extra R&D taken place by the major manufacturers of props?
The whale being a slow mover has no cavitation to overcome so I find it unlikely it’d be much help with that, an owl on the other hand can fly stealthily with modified feather placement, but with the fluid viscosity being so different, it won’t work in water.
and if you scaled up the propeller significantly?
In my opinion even if it gives small gains in thrust for the boats it might be not profitable from manufacturing perspective. Making this kind of pattern in the stainless steel might not be an easy task. I can imagine it being first introduced in the small scale or in computer fan propellers. Of course if this gives any profits to air flow and acts well in high rpm conditions. Another aspect is if anyone has a patent for that.
@@aikenPL true about the patents especially, they could literally kill it dead in the water due to unreasonable licensing fees. (Pun intended)
No it was not tested first in 2008. WAY WAY before this. Decades before this. He needs to do more research. I read a paper as old as 1930's on it. So, it was probably done before then as well. Got me. Most ideas require a lot of $$$ to implement in a mass produced product to change industries.
@@w8stral could you share the 1930 reference please?
I liked that you used the word "adapt" about the lizard after 5 min. Many content creator use the unscientific word evolution.
Nature paper says "Our findings present a possible avenue for mitigating cavitation erosion through the application of inexpensive and environmentally friendly materials." It kind of seemed like you were saying GEMS would help mitigate the sound of the propellors and engines, but GEMS allow for louder propellors because the surface coating reduces cavitation damage and not cavitation itself, in theory allowing for faster and louder propellors.
So what if you combine tubicles and toroidal props?
Please avoid murdering children for the religion of their parents.
If you want to talk about advancements in prop design, you might have mentioned the Sharrow prop. Totally different design, uses a third less fuel and produces more power. Used mainly for outboards but i don't see why the wouldn't work on a larger cruising boat.
I can just imagine the advertising slogan if such props become commercial; “ribbed for mother nature’s pleasure”.
I became aware of the 'tubercle effect' at _least_ 10 years ago.
I'm a a bit surprised it hasn't been adapted to say room fans, as IIRC it moved 50%(?) more air using 20% less energy and was quieter than 'normal' fan blades.
So maybe it isn't quite as incredible in application. PC fans have had serrated trailing edges for 20 something years though so maybe in that small of an application in a fluid as thin as air it works to reduce noise
I learned about cavitation bubbles while watching vids about steam ocean liners. If a propeller was not made properly, it can cause serious vibrations throughout the ship, and make it uncomfortable for the passengers.
Interesting to see this kind of innovation, sure don't want to stick your finger in a fan that has teeth though.
Sticking a finger in a fan is bad whether or not it has teeth.
MAGA people would do it because they were told to do it.......dah
Wow, this video was super informative and entertaining! I’m a new member, and I just wanted to share something. Being next to a wind turbine isn’t bothering me at all. The slow-moving, huge wings make a low, almost humming noise that’s so soothing. I have relatives who live pretty close to a turbine, and in the summer, it’s like having a natural lullaby. It’s the best! Get some fresh air and enjoy that humming noise that lets me sleep for hours. Cheers!
Pretty sure I've occasionally seen such ridged blades used in PC cooling fans for at least a decade now. They pop up now and then when a manufacturer claims a new breakthrough (as they do with every single new fan), and then the next generation after that goes back to being straight-bladed.
Wind turbines too, they got them on the trailing edge for a while now
I think Noctua still has some ridges along the blades of their fans.
Have you looked at the duo prop? Volvo-Penta introduced the idea a number of years ago, 2 props on the same drive shaft, turning in opposite directions. I can't remember the specific numbers but these props gave significantly better performance.
Best of all, they backed it up with production. The Volvo-Penta IPS drive for motor yachts comes with duo-props.
I am not familiar with maritime applications. In aviation however,just before the jet age took over,
aircraft such as the F4U,P47,P51,Seafire FR-47,were built with contra-rotating propellers.
2 three bladed props. YT has a great video of the only airworthy Seafire FR-47.
The Seafire FR-47,a Spitfire variant,used this design to neutralize the torque effect of the engine,
so as to utilize more power on take off from aircraft carriers.
Contra rotating- opposite rotation,same axis
Counter rotating-opposite rotation,different axis (P-38)
Cheers
@@billysolhurok5542 and the helicopters that have contra rotating props don't need or have a tail rotor.
Another interesting propeller design since you asked is one I saw where instead of contra rotating props one of them is essentially a stator, ie fixed, which has produced surprising and promising performance improvements.
What's surprising about thar? Counter rotatimg.props are not used because of their crazy noise levels giving you no access to civilan airports. Russian military does use them on some models.
Some militarry argo planes use them as well. The bypass mass flow ratio is way higher.
@@voster77hh so obvion!
These are actually on my list of things to look into! Hopefully a video on these will be underway soon
@@ZirothTech brilliant, ty
@@voster77hh There are some claims out there,
that a lot of the Counter rotating prop noise can be avoided,
if you have a different number of blades on prop 1 and 2.
Makes sense to me, but I'm not an expert.
I cannot wait to see the fusion between bionic and the MIT toroidal propellers
The future of thrust is bright, and Bionic Contra-Rotating Toroidal Propellers are poised to play a pivotal role in shaping that future.
I live on a sail catamaran. I can hear large ships passing by from my keels it’s crazy how loud they are and the oldest ones are the loudest
When I was a kid growing up on the St Lawrence River we could hear lakers coming from a few miles away easily. Those big single engine lakers sounded like a rythmic bump bump bump sound if your head was underwater.
Excellent information, thank you for putting this together. Nature always has the best ideas
On the next episode of rctestflight
It's astonishing, we manage to get tech and than need to look to nature to improve said tech.
Looks like whale flippers. Time to watch the video..
Biologist, Frank Fish.
I just love these names that forge your life choices and interest so directly.
You're telling me his name was Dr. Fish?
I have the feeling that Dr. Fish really is in his element doing miritime science!
You printed a bionic propeller and you never showed it spinning in water?
Funny... We've know smooth surfaces aren't the best thing since the creation of the modern golf ball. Nice of you tocatch up a century later.
What would be the benefits if the bionic shape would be implemented on a toroidal propeller? I would be very interested to see some test and what is improved or not with such a propeller :D
Cavitation is extremely loud! I was in a ferry. The mechanic took me to see the engine room. He was extremely kind and informative. Then a horrible banging and rumble started very suddenly. It felt like the ship had bottomed out. The mechanic said, "cavitation! We just changed that propeller! I'll be back!" He took off running screaming into a walkie talking about what was going on. I do not know why he was so upset. I did not want to anger the mechanic, so did not ask. He came back a few minutes after things smoothened out and apologised. He was not happy at the operation of the ship. But, I never asked him what issues could arise from the cavitation. This video answered the question.
I can’t stop laughing about the fact that the biologist’s name is “FRANK FISH”
I came up with a biomimetic propeller design back in 1997 or 1989 while working at Arcturus Marine Systems. I even have a "poor man's patent" of the idea - I mailed drawings and notes of the concept/design to myself in a stamped and sealed envelope. I even put an extra postal stamp on the back of the flap and had it canceled manually before I mailed it to myself, I still have that sitting in my fire safe.
Could you combine this with toroidal propellers?
Would love to see someone test that
Only way to get people to convert is to combine it with a performance enhancing prop.
Same thought.
@@William_ar98exactly we @rctestflight to take the wheel on this
Me too. Especially if it improves the life of sea creatures and saves fuel@@William_ar98
Additive manufacturing at home is going to revolutionize many things. I'm already picturing how easily multiple variations can be produced and tested using plastics, before anything is committed to casts or die molds for metals. 👏
Would be interesting to combine bionic and toroidal propellers. 🤔
Dr Fish has to be the greatest name I’ve ever heard
Seems like mother nature has done this for millions of years and knows what she does
Mother nature also doesn't spin at thousands of RPM's. Not all the comparisons made are valid, but we definitely can learn a lot from nature! We live in a really interesting age!
Guided evolution is not a thing, which is why only 1 species of "fish" has tubercles.
Well... living beings ARE highly advanced technology. WE are all bionanotechnology. I mean look at enzymes, those are bionanomachines.
Thank 🐢 you. Years ago when working on a ruff' sandy beach we 'toar up' the prop and noticed reduced vibration and cavitation.
And as a kid I noticed the wind trails during foggy weather were smoother from fence pickets with weathered tops.
I'm wondering if the US Navy already knows about this....and has gone WAY beyond. They cover the propellers of the submarines. Would be interesting to know what they look like.
Yes, it would be extremely interesting, especially to a foreign spy. Why do you think the Navy covers them?
I've owned a long string of boats since the age of 16 - 63 years ago. Little boats at first then bigger and bigger boats. I learned about cavitation with my first ski boat. I never gave much thought to it just adjusted the boat to the point where it was most effective. I read about these propeller designs earlier but your information about the whale was very interesting. Manufacturing cost and variability are the prohibitive constraints right now. I think the manufacturing issues will be worked out over time but they will still be costly. The same considerations have been used in wing design for some time. As to creative design, it is what human kind does. One building block at a time, each one enhancing what was done before. Every now and then something new will come along but even in that regard there is most often a history of development. Even some of Einstein's thinking was based on the creative thinking of other individuals. Good report.
So can these shapes and their effects also be applied to toroidal propellers? Because toroidal propellers seem to already be more effective compared to traditional and traditional with these modifications, so are we able to mix the two ideas in a way where we gain even more effectiveness in the toroidal performance for efficiency and sound reduction?
I too, am extremely interested in learning this.
That gems idea sounds outrageous. Truly, truly, outrageous.
What about using golf ball dimples on propellers like was done on Mythbusters to improve MPG on a vehicle? Add that to the whale design then see if that does anything more for efficiency and noise reduction.
Completely forgot about golf balls, I was so deep into the tubercles research! This is definitely interesting, I'll get digging and see if there is more interesting things to learn on the topic of dimples
@@ZirothTech Great to hear!
Wow man! Good Stuff! I'll be sharing this link. It is not just the propellers that grabbed me, but its resemblance to the strakes that reduce the drag of wind and fluids on towers in storms. I bet we see a tie-in as research continues. Thanks for the show!
Nice vid. Tho almost every time you say bionic you mean biomimetic.
He clearly tfk says biomimetic wtfk planet are ya on pretty sure it pertains to the prop surface at least in the context that its used in the above video so biomimetic by definition describes relation of prop surface fkn texture as it has relitave effect speeding through water strictly upon cavitation or how it affects prop surface when prop encounters cavitation mainly not fkn destroying the prop using mushroom shaped wtfk ever jfc I didn't graduate 7th grade but even then it's pretty clear like water clear if the listener enjoys entire video or is able to retain attention span of a minute plus lmao. And yes, the apparent lack of punctuation and run on sentences deffinatly proves that 7th grade drop out knowledge!!!!! Lol
It's amazing how much improvement we can make to structural engineering by just trying new shapes.
Please use the Metric System as used by 94% of humanity.
This ia AMERICA! Go back to Europe !!😂
I’m glad they don’t. I hate the metric system. So many writers use it wrong. I once read a story involving a crew member of a space ship being a few centimeters taller than her fellow crew members, described as “towering over them.” Intrigued, and not being very well versed in the metric system, I used a formula to convert it to the standard English system and it turned out that the few centimeters converted to two or three inches. Towered over the others, indeed. If two or three inches is towering over others, then being 5 feet 10 inches tall, I must be a giant. 😅😊
Less than 10% of the books written before 1960 use metric. Very few of the Europeans I've met know what a pascal or a dyne is.
Just a simple observation. I was flying a custom home built 30" span rc model with a standerd 6x4x2 blade prop. It behaved like an underpowered aircraft literally hanging on the prop and quickly went down in a farmers field. I recovered the plane and noted the leading edges of the prop were seriously scuffed up as though a sand blaster had hit it. Not having a replacement blade handy, I launched it again. The result was a dramatic performance improvement in speed. However, noise was much greater. The only change I could attribute this to was the blades leading edge.
I have an old prop that’s washed out. Meaning run so much the water grooved the blades. They look just like the bionic prop. Nature was telling me. I just wasn’t looking. In fact, until this video I never gave it a second thought. Thanks man 😊
Seems nature is always the best teacher. Great video, thank you.
Loving the SHARROW by VEEM Toroidal props currently under testing, looking forward to seeing the results they produce.
Natures has had the blueprint from the start, we just needed time to understand how we can work with it. Hopefully a brighter future and deeper respect for nature as we advance as a species
Hydroelectric generator turbine blades may also benefit from these design improvements if they provide a meaningful efficiency increase and reduce cavitation damage. Mother Nature is a great teacher. Thanks for the video.
Relatable observational brilliance. Whale forelimb groved flippers to air and sea propeller designs. And quieter too!
Thank you for a clear explanation of a subject most do not have a lot of knowledge of. The answer of every question humankind has is in nature, if we take the time to find them.
Planet mentioned within 10 seconds. Good job. Tow that global space ball story everywhere, even to the flat water of the sea.
In 2006, I worked with one of Dr. Fish's grad students to build a tubercle wing for a race car. We had a 40% model made and ran a full day in a wind tunnel (AAR in Santa Ana, CA) to test. There were some effects, but they were very, very small. We often run stalled or near stalled and in that situation, it just wasn't much of an effect. We were hoping for the best and stuck about $50k into the project, but we never got anything out of it. We know that at least one Formula 1 team investigated the idea and I never saw it on their car.
The student was from Cal Tech. He was brilliant, but we ended up parting poorly when he started trying to claim results that the data just did not support. I was really disappointed that a PhD, from Cal Tech no less, would stoop to this level. I'm in racing; bullshit get called early and aggressively. As I've gotten older, I've come to think he was just a product of the institution which he was trained, as we've seen many from prestigious schools will do the same thing.
I’ve learned more from yt than I ever did in school
without question, the education system has long been broken.
Hi. The small insects that "walk on water" rely on surface tension. Water forms a "meniscus" because its molecule is polarized. This is why the flat surface of your cup-of-tea curves upwards where it joins the sides of your cup. It can curve downwards too if the sides of your cup are dry. Nice video, thanks. P.R.
When we returned from our honeymoon, we stopped at the Albacore museum. There was a vessel on display with an experimental "cavitation drive" - two nacelles supported the main body, with the propellers at the front. The idea was that cavitation would lower the resistance of the nacelles. Supposedly it did about 60 knots.
This channel reminds me of “The Shark’s Paintbrush” suggesting wall paint that mimics pond dwelling lily pads that float partially because they’re designed by nature to let water run effortlessly off them promoting buoyancy. You sir are Not all talk. You actually are making a difference. Your friends remind me of Jacques Cousteau. Thank you for the effort and well done indeed sir.
Brilliant. Biomemetics is still in its infancy and already shows great promise. But what about the strange propulsion dynamics of squids and octopuses? If there were staggered systems, it would even eliminate the surge and slowing effect.
It’s actually kind of impressive that no-one have though of it long before, plus there are likely hundreds of thousands of other things we can improve by mimicking nature.
Traditional propellers used in marine and air transportation have two major problems - cavitation and excess drag. Cavitation happens when the pressure on the low-pressure suction side of the blades drops, causing water to vaporize and small vapor-filled bubbles form. These bubbles erode the blades, reduce efficiency, and create noise. Excess drag is caused by the angle of attack between the blade's edges and the direction of the oncoming fluid. Managing these two problems is essential to improving propeller efficiency, which is critical for reducing noise pollution that affects marine animals and aircraft passengers. Biometric solutions inspired by nature are transforming propeller design. For example, 3D printed propellers based on the tubercles of humpback whales, which reduce drag and improve maneuverability, have been tested with promising results. Propellers inspired by the flippers of penguins and the scales of sharks have also been developed to improve efficiency. These biomimetic designs could reduce noise pollution and improve efficiency, which is essential for sustainable transportation and protecting endangered animals.
My background is that of an unlimited ton captain, seeing the toroidal propeller had me thinking about if it could pay for itself by the time it was past its service life. Took in factors such as increased fuel efficiency, better thrust, and less wear and tear on the propulsion system. At the time a started calculating, it unfortunately did not pay for itself. This is in regard to the 45” diameter bronze alloy prop i need to use. I also need 2.
These bionic propellors have me excited. I need to research the price or a quote but i know they will be a fraction of the cost of a toroidal prop. Not a ton of published testing for the bionic prop but as soon as their is enough info, im hoping the gains can pay for the bionic prop or even start to make me a profit
I've heard noisy propeller planes fly around and I've heard them long before I saw them. I can't imagine being underwater and seeing the wake of a speed boat sailing around. I also LOVE biomimetics. Nature uses fractals, we use them. Winglets in commercial aircraft, we copied wingtips in birds. Velcro come from hitchhikerseeds. Syringes started to copy mosquito needles.
Love me some atmospheric mass effect background music. Fantastic and informative video.
I tried to share this with an airplane propeller manufacturer .
He was quick to slam the door shut as nonsense.
Glad we are working on proofs and measurements.
It’s about time!
Thank god….Who invented the bump propeller! 😊
Thanks for this elaborate, yet easily understandable breakdown of this 'seemingly new' Technology 👍
It's always good to hear the latest in underwater developments...form a guy named Fish.
As a youth I love ved fast boats, extremely fast boats. I learned from John McCall, inventor of the tear away cowl in race boats was also an expert on props, he'd get as much pitch as possible then cup to tune, running wheels he built required the prop to be a tad over halfway out of the water in line with the planning surface. Also a modified V with a very small planning surface helps as well. Performance wise, they were dogs out of the hole, (to get on plane) but once the prop bit, it'd set you back in your seat hard and the howl the prop made, could be heard from Sarasota Bay to the Venice Inlet (Jetty's) the boat went from a 50 mph boat, with Factory sized prop and a 75 3 cylinder on 14' boat (Allison, factory Built Race Boat) to 75+
A few buddies and myself, all working class fellows had to compete with the Billionaires across the intracoastal waterway who'd buy the best they could find but they couldn't buy the wisdom of John McCall RIP
0:46 the '..but first' here almost killed my willing enthusiasm 🤣
Feathered propellors are like owl (silent) wings - with little or no cavitation or air bubbles. Using front-end feathering, and/or back-end feathering diminishes cavitation, but also diminises water surface drag. Like the same that should be used with helicopter blades (and the thunk, thunk, thunk sound) you need to use the same upturned wind tip, shooting the sound of the propellor upward and away from equal or underneath viewers/listeners. Also feathering the back end of wings also silences the wings, but also stop further air drag and noise. Water propellers outward edge (like the torroid propellor) having a feathered edge further silences any vibration, engine combustion explosion and bearings noise passing into the propellor into the water.
Manatees in Florida suffer horrific injuries from boat propellers. Simply adding an external ring would be a huge improvement. Making a more efficient propeller makes it a no brainier.
I would love to see this being implemented for drone propellers.
I was thinking same thing but you want lift created by the low pressure above the propeller so I am not so sure. Do drones get lift from the prop or is it mostly just pushing air down?