I Found the Most Efficient Propeller Design - Competition Ep. 3

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[@danielcaigou]

Props to this guy....

[@akindaanimations]

Ha

[@Very_Grumpy_Cat]

Haha nice

[@starlins_son_oofd3898]

Someone had to say it

[@LeertasteTek]

you mean Poop ? birdpoop... ?

[@JowieC]

I sea what you did there

[@DanHeskett-n1c]

The honorable mention for this video is the bird who bombed you in stealth mode.

[@dadsfriendlyrobotcompany]

Yeah, he should find it and model a prop from it. Silent but deadly

[@ataboo]

@@dadsfriendlyrobotcompany That bird has surely mastered laminar flow.

[@52Quantum]

That's nothing. I once saw a kid put his rucksack in a dog shit, then proceeded to put it on his back. His reaction was the funniest thing I've ever seen!

[@BadwolfFPV]

better the back than the head

[@alant779]

It was the duck he bullied a while back.

[@Powertampa]

That the toroidal is so much quieter while matching the performance of the baseline is actually a big positive if you think about it. Reducing noise and thus potentially vibrations could be quite the big implication for some applications.

[@BarackLesnar]

It's good for the fishies too

[@audioadventurer6892]

@@BarackLesnar And therefore also for fishing.

[@contrail52]

It was so much fun having a chance to design my prop for this competition and flex some of the aero engineering muscles from uni. Can't wait for round 2 :). Most of the bugs in my design workflow and software were ironed out during this round, so there is nothing stopping me from placing top 3 next time! Congratulations to Spanmaxxing, Bigger (Diameter) is better, and Prandtl-DAE!!!

[@DC_DC_DC_DC]

You should start testing irl yourself and send your footage to be featured!!

[@contrail52]

@@DC_DC_DC_DC While it would be a fun project and a fantastic video idea, the lakes near me have a visibility of -2 feet and my free time right now is being eaten up by another RC project. I'll give it some thought though! Thanks

[@dominiq4343]

​@@contrail52would you be intrested in making videos of your projects? I would love to see your ideas.

[@contrail52]

@@dominiq4343 I'm not opposed to it. It would be my first time making videos of any sort. And I would have to work around a full time job. Though, it might help to keep me working on my projects with some level of consistency lol. BTW, the project I'm attempting right now is to design and build a scale model F-18 HARV from scratch (flight controller too, down to the pcb).

[@mexail86]

​@@contrail52I wrote to you on thingiverse, you can see my message😅

[@BenjiMeisterDK]

i like the side story about the drone owner

[@Toolingabout]

Odds that it was stolen?

[@vegasu9418]

​@@Toolingabouti mean that was a black guy so what do you expect

[@dmitryplatonov]

​@@Toolingabout I'd say pretty high.

[@squidikka]

@@vegasu9418 lmao

[@0x0michael]

​@@Toolingabout Racist

[@mdsign001]

Can't believe I'm actually excited to see a THIRD episode on propellers!

[@flat-earther]

hi mdsign, have you become a flat earther yet? If not I suggest watching _Level with Me (2023)_ by Hibbeler Productions

[@flat-earther]

hi mdsign, have you become a flat earther yet? If not I suggest viewing the 13 part series _what on earth happened_ in my about to learn how the earth is not a globe

[@dosendaring]

@@flat-earther that's an old theory, I have a new one, THE EARTH IS CYLINDRICAL SHAPE.... !!!! That is both flat and round at the same time. Think about it.....cars have cylinders. Mindblowing.....

[@talon9639]

​@@dosendaringwhat the fuck is going on😂

[@carpediemarts705]

I've been watching the computer fan showdown for 4 years now. Never thought that would have so much pull!

[@N330AA]

33:50 Military ships often have variable pitch propellers. Arleigh Burke class for example, and the props are huuuuge. And they have a bubbler system too to mask prop noise.

[@Kenionatus]

Great example of needing to run at different speeds, I guess. I imagine that sometimes they want to move somewhat efficiently so they don't guzzle their oilers empty too quickly and sometimes they need to haul ass to dodge that torp or get somewhere yesterday stat.

[@namibjDerEchte]

@@Kenionatus Actually, at least for planes, also because airstream velocity cancels out blade pitch to an extend.

[@Stormcrow_1]

Back in the day the Type 42 destroyer used to have CPP. One of the reasons we had cpp was to allow reverse thrust, without having to make a gearbox able to reverse the shafts.

[@authordent41]

To reduce hull friction

[@N330AA]

@@authordent41 Nah, they're called Prairie Maskers which make ships sound more like rain to submarines. You are thinking of hull ventilation which is used on some extremely fast boats.

[@RubenKelevra]

Variable pitch propellers are actually kinda common on fish trawlers, which need to operate at two speeds efficiently: The travel speed and the harvesting speed. This also helps with maneuvering, as they can seamlessly switch between forward and backward operating in fractions of a second and thus can keep the boat stationary at a certain location (if they got a bow thruster). So deep sea diving boats have also often also have variable pitch propellers, which can sometimes freely rotate. But the pinnacle of maneuverability - sometimes used on tug boats - is clearly the Voith Schneider Propeller. But it's also pretty inefficient - for obvious reasons. *BUT* they have a low acoustic signature - as they don't have any cavitation, as they don't have tips (there's a thrust plate at the bottom). :)

[@kecuthbertson]

They're also common on larger motor-sailing yachts where they will vary the pitch to maximize the amount of power they can get from the sails whilst still maintaining a reasonable speed, or they can feather them entirely whilst using only sail power.

[@valentinguz]

Such cool different design

[@TlalocTemporal]

Voith Schneidy propeller? * Furious typing * Cyclorotor‽ Wow!

[@BiscuitWaite]

They are also used on gas turbine ships. Since turbines only spin in one direction, the only way to get reverse is to reverse the pitch of the prop. Ask me how I know what's it like when the pump fails on that blade and the turbine is spun up to full power.....

[@agentcrm]

Those Voith props would break many peoples mind. Especially when they're used to to move the thrust around the tug.

[@HolbrookAerospace]

Great episode! Thanks Daniel for using our template, helping expose the HAVF airfoil format, and being so patient with our first foray into marine propellers! I love the content!

[@algawura2]

Thanks for these videos. I tried out spanmaxxing for a DIY aquarium flow pump and was blown away with how much water flow was being produced. Fewer flow pumps can be used now to support the live corals in the aquarium. Thanks again for sharing.

[@okami220]

38 min video to kick off the friday, Daniel you know the way to a man's heart

[@dominicrichardson5546]

Released just in time for my lunch break, perfect timing.

[@BongoBaggins]

I know far more about propellers than I ever wanted to know, and my life is immeasurably better for it

[@gunnarblomquist5108]

Thanks for testing my poorly proposed prop! Nice touch with the Sea shanty lyrics

[@WigglesMcMuffin]

Obligatory "that's not really a sea shanty, because it doesn't have the work/rest structure". Wellerman is still an awesome song though

[@humanityeliteschool9407]

the reason why Fibonnacci prop came at bottom is that it is designed to generate max energy from flow, meaning it's a generator, turbine prop not the thruster prop. if you put that golden ratio prop on boat and replace sail with that it will generate max amount of energy per sqm. and if you connect it directly to the shaft of water prop then you will have the fastest most energy efficient wind boat that can outperform any standard sailboat(nonfoil). 100% I am building that!

[@Project-Air]

A showdown for the ages 🙌

[@Unapersonaconunmicroscopio]

You could do similar testing but on air instead of water

[@WesleeHoffman-me3cw]

Yeah that would be a really cool video because your view can participate

[@johnsmith-jq1uc]

real, if possible it would be cool to see you do a verison of this.

[@drewharrison6433]

​@@UnapersonaconunmicroscopioThe conclusion of this series was that each propeller has to be optimized for the power source and speed of the vessel. If James did this test, it would be for a particular motor and aircraft. It seems a bit pointless. If you ask me, I want James to do more speed record attempts!

[@therealistmccoy6237]

Oh shit it’s project air!

[@Aperson156]

This tickles a tism I didn't know i had.

[@Sandux930]

whats the A stand for?

[@nikkiofthevalley]

​@@Sandux930'tism is a shortening of "autism", the 'a' isn't short for anything.

[@sunfishensunfishen2271]

Literally same here

[@zachmoyer1849]

every guy loves a boat

[@nikkiofthevalley]

@@zachmoyer1849 Autistic people aren't necessarily guys

[@williamfraser]

You can isolate the propeller efficiency from the rest of the system by using shaft power as the metric. Torque times rotational velocity. Torque is proportional to current so using phase amps x rpm will give better prop comparisons. You also eliminate losses in the esc this way.

[@3gunslingers]

Wow! Brilliant research series! You are just casually uploading videos with _far_ more research content than many bachelor thesis out there.

[@PatrickHoodDaniel]

The acapella at the end is 🔥!

[@CameronDickson-fe5uj]

This confirms he is using us to make the most efficient solar tug boat yet

[@WildHair1]

@32:20 Daniel's Thoughts From A Weird Vehicle is my new favorite segment.

[@riipper666]

As a maritime engineer with experience on model tests of propellers, this is very interesting. The different aspects of propeller design are nicely shown and discussed here. As for the cavitation, the large propellers are more prone to it due to the high tip speeds. When doing model tests with roughly similar sized propellers than tested here, the pressure of the test section is lowered to 20-40% of the atmospheric pressure to match the cavitation of a full-scale propeller.

[@reyalPRON]

This is interesting indeed, i miss a traditional hub variable pitched version in the line-up. Pretty sure that is the way to go, as one does need a gearbox for reverse as the blades are just flipped.

[@thomasvnl]

The sound analysis was really cool, and one would think that a less noisy propellor with a good integral efficiency must be a result of less cavitation/bubbles. Spanmaxxing sounded rather clean

[@SpeedyGwen]

the thing am curious about is how much sound there is depending on the angle, like, its probably a radically different volume between in front of the ship or from the size or behind it

[@bolbyballinger]

I think there's a few problems with tubercles. In nature they're strongest on the side fins rather than the tail fin, which often won't even have any. Essentially they're more useful on the whale's "rudder" than the whales "propeller". Which might key us in to their actual purpose. Further, whales are not speedsters. While a blue whale CAN hit 30mph they're usual pace is 4-12 mph. While the boat in these tests is within that range, the propellers are moving fast enough to "reverse" in the camera meaning they're rotating at a pretty serious clip. So the tubercles that are usually on the steering part of a slow animal are being placed on a high speed propulsion part. Somewhere nature simply never intended them to be. Even more, they're not made for this kind of motion in nature. Even when the whale is zooming the tubercles on the tail are going up and down (changing direction) with slow downs and even stops. But on a propeller it's just a constant rotation in one direction. If tubercles do offer an advantage to boats it'll probably be on the body or the rudder.

[@TlalocTemporal]

I think there has been some success with the tubercles as a wavy leading edge on plane wings, specifically in that it makes it harder to stall. The idea is that the wing has a variable chord so the stall happens gradually across the wing instead of suddenly from one end. This is the same reasoning behind Dog Teeth (or Leading Edge Cuffs) and Wing Washout (or an axial twist) on some planes, which actually just has a different stall speed on different parts of the wing, so stall happens on just one part of the wing and more evenly between wings. Also a feature of Dog Teeth, and often added to normal wings, are Vortex Generators and Wing Fences, which can prevent a stall from propagating along the wing, and also help spanwise flow separation in swept back wings. All of these anti-stall techniques may be generated with tubercles, and it makes sense that the flippers get more of them; in order to manoeuvre quickly, you need a high amount of possible lift in several directions, and a sustained reliable amount because taking another stroke takes a long time. The tail can be angled to prevent a stall, but the flippers need every degree of angle to turn quickly. In conclusion, I fully agree with the sentiment that tubercles don't belong on propellers and instead belong on manoeuvring surfaces. I had though I had seen a helicopter with wavy leading edges on it's rotors, but I can't find it. F1 cars nearly use this in their wings, very interesting look nonetheless.

[@ruftime]

Awesome stuff! I come for the video……and stay for the outro song❤

[@6n-thorus945]

Contender-25 is realy intresting one, same diameter with baseline, but as big top speed as spanmaxxing is great result i think if there will be another competition, you should limit maximum diameter at baseline propellers diameter, so it will be competition of form, not size

[@contrail52]

Contender-25 did have the greatest efficiency at higher speeds than the other 34 designs I tested, which is the main reason that it beat out the others. Though, I never considered 2 blade props, I only stuck with 3, so I was kicking myself when I saw the other 2 blade props lol. But seeing that top speed in the results was a great feeling. If there is a second propeller competition, most of the bugs are worked out in my design workflow and software, and I have new ideas :)

[@th3welfarewarrior]

the amount of work for a 30 minute video. Wow. Congratulations.

[@RoofAndAMeal4UsAll]

Yep I've got a 3 blade R/C aircraft prop on the 55lb thrust trolling motor on my electrified paddle/pedal boat. Increases current draw, doubles speed. I appreciate this channel, however I should point out that the ads are louder than the baseline audio gain, you might want to bump up your audio gain in order to lessen the jarring effect on the viewer of the noticeably louder ads.

[@nealstephensonhiro72]

Hiya! For science would you share the exact prop ( maker, diameter and pitch) please

[@RoofAndAMeal4UsAll]

@@nealstephensonhiro72 sure made by Windsor Propeller Company it is a 3 blade pusher, T3871P is stamped on it, also T15704. The blades measure 7 1/2" to center, it is large. It is in their catalog. Wiring should be better than 10g. At low power settings it is efficient and fast. Running it at max power things heat up and curiously do not result in more speed. Your mileage may vary - I'll share it for 'pseudoscience' let's say as any wind has a pronounced effect on my big square craft making precise measurements suspect. Snow Crash! :)

[@nealstephensonhiro72]

@@RoofAndAMeal4UsAll thanks for your reply! Yes loved Snow Crash ages ago and it influenced my YT name choice haha

[@johncarter5576]

I owned a 21' open bow boat used for pulling skiers, tubers, wake boarders, & knee boarders. It had a "Torque Shift" variable pitch prop the was great for getting skiers out of the water fast & a much faster cruise than a lower pitch prop could provide. It's only problem was exactly what you stated, living underwater the shift mechanism was constantly needing to be cleaned. Thanks for providing me with even more items I feel like I need to 3D print!

[@appa609]

Thank you for helping us validate our design methodology with this real world test. Hopefully the next one flies (soon)

[@contrail52]

Congrats! Hopefully I'll get to see another one of your designs in a possible round 2.

[@blakebrady9002]

US Navy ships use variable pitch propellers, they pitch all the way around allowing the propeller to achieve forward and reverse thrust while only spinning one direction

[@BrekRND]

Grew up racing planing hull boats, and we always ran the centerline of the prop around 12-18mm below the water. The best explanation I have is due to drag of the gearbox and fin. Also running at 100mph.

[@GoldenCroc]

It depends heavily on the type of boat/hull what is the best height. Yes, it is indeed done as good as exclusively because of lessening drag. Some boat classes have a regulation height of prop shaft measured from bottom of the hull.

[@martindinner3621]

And this introduces surface piercing props!

[@Chris-oj7ro]

This has been amazing! Thanks to you and the people who made submissions. It's been a great contribution to the vidnet!

[@hmoxh]

Kamewa has made variable pitch propellers for like 80 years and they are considered very reliable. We had them on some boats when i did my military service.

[@Th33M4rksman]

i honestly know literaly nothing about design, engineering, mechanics, and watercraft, but these have been so entertaining and informative that it doesnt really matter much. i want to see you review rc dirigible propellers now. and im aware those probably dont exist. but if they did, id love for you to review them.

[@moki123g]

If you like this style of engineering content (even if you don't fully understand it) search on KZbin for: this old tony, applied science, and nile red. There are many others, but that is a good start.

[@swingsloth]

Just when I say I'm going to turn in and go to sleep. Looks like I'm up for another half hour.

[@TurboJohn74]

As with designs in many other applications, everything is a compromise. Loved the breakdowns after testing.

[@ericsynchrona5495]

"Next I've got these human growth propellers from a science lab, these were actually designed on the backs of real human beings."

[@NOTNOTJON]

Thought Imporium has entered the chat

[@speedstrn]

It's too bad there aren't any living organisms with propellers to have natural selection choose the best design. Maybe we need a mad scientist to get on that and we can check in on the results a few million years from now... We may need a time machine for that.

[@aleksihiltunen7063]

@@speedstrn We can run genetic algorithms on our computers still although they don’t always result in the most optimal solution in real life as shown in the video

[@NetAnon]

@@aleksihiltunen7063 Yeah, evolutionary algorithms only really select for the nearest best not the absolute best.

[@connosaurus]

Island of Dr. Moreau enters the chat

[@johnharris5786]

My prop did so poorly! I really thought it would do much better than that. Notwithstanding, I really liked the video. Keep up the good work Dan and thank you for the opportunity. I'll be sure to try again next year if you do it again!

[@TheoriginalQward]

Great series, Onto self-guided submarine!

[@sfllaw]

33:40 A legitimate marine application for "variable" pitch propellers are the folding propellers used on sailboats. These unfold when under power, but fold under sail to reduce drag.

[@Highspeedfutzi]

We need a crossover with the Fan Showdown from Major Hardware! 😁

[@contrail52]

If it's any consolation, I've had a prop here and a fan over on Major Hardware. Contender-25 here, and the Tick-Tock Clock fan that he showed in a special episode lol.

[@tomallo99]

@@contrail52 Oh, it was so cool! Umm, what can I say, thanks for your contributions, major props to you, I'm a big fan :D

[@NicholasRehm]

God bless good ‘ol APC props

[@NicholasRehm]

Okay but the discussion at the end was so well done covering all the nuances of this experiment. Awesome stuff

[@connelly6375]

Blesa that man's heart who taught his brother an important life lesson, never sell when you're desperate

[@jamesbramlett5407]

SUCH a good series! I bet you're sooooo happy this is over and done with. We really appreciate the countless hours of work you've put in.

[@innercityprepper]

Seriously one of the best channels on youtube if you like learning stuff, and also learning how to learn stuff.

[@sam1812seal]

Not only are ship props designed for a set speed, their bows are too. The bulbous bow is designed to decrease bow inefficiency at a set speed. Outside of that speed the bow might actually increase inefficiency. Maybe the next design competition is bow shape?

[@SigFigNewton]

Rocket nozzles are optimized at a specific altitude

[@SigFigNewton]

Well. Ambient air pressure

[@mkkls]

A naval architect here … thank you for a very entertaining and educational test series. You had your facts straight, pretty well understood and clearly explained. Also nice to hear about people eager test their own ideas with openfoam and other cfd tools. I cant help thinking about the six digit price figure that a professional test facility would have charged for a similar test campaign.😅

[@ramble3539]

Would be nice to see these props tested on more powerful motors

[@kenselleck2414]

Loved the whole series of tests but the cherry on top is the song at the end!

[@DitchWizardry]

The 'mist' from the cavitation on the APC propeller is probably residual gases other than H2O which are staying in solution with the water as gas when the H2O vapor collapses. That's my theory -- dissolved atmospheric N2, O2, etc., failing to redissolve instantly. You've shaken some of the tiny amount of natural fizz out of the water. 'Fish hate this one trick.'

[@martindinner3621]

Sounds like a solid theory!

[@DitchWizardry]

@@martindinner3621 I wanna say it was something the Slowmo Guys or Hydraulic Press Channel were doing with cavitation where I saw the effect, or maybe Mythbusters twenty years ago??

[@we4selradio591]

the 3d view of those swirls around swirls around swirls all intertwined in motion at 21:55 is beautiful.

[@tyler4306]

Maybe the whales have evolved to hate the sounds of propellers, if they fear the sound of propellers they will avoid getting hit by one.

[@jojo-._.]

That drone guy is awesome! Edit: Man I ran out of time yesterday and only watched to like 31 minutes. I think the tug boat tour is the most surpreme form of narrating and giving thoughts, while Daniels POV was very cool to see!

[@MikeyMobes]

i love the b-plot

[@reedreamer9518]

What's most impressive here is the development of your instrumentation and testing methodology. Very well done.

[@egret203]

This whole series has been *fascinating!* Thank you for putting in all the effort. And congrats to all contestants and the winners. Also, your humor is right up my alley! I laughed my arse off with the massive birdshit incident and the super quick "I'm peeing" cut. lol

[@NeverlandSystemZor]

What I love about this is that it's ingenuity and playing around with ideas by people- THIS is the testing and innovation every hardware should have from passionate and interested users.

[@yoloswaggins2161]

That dude low balled his brother for a drone wtf?

[@ammerudgrenda]

I’m an aerospace engineer and commercial pilot…and I give this video 5 stars! Keep up the good work 👍

[@aaronlocher7059]

I love your videos. Currently finishing my bachelor in material science and engineering and coming across some of the phaenomena you are dealing with. I am so happy to see the somewhat scientific approach you take and explain the different topics and aspects. Looking forward to your next videos and maybe I might be able to submit to the next competition.

[@KingofArsenal]

Hey there, we are back! This series took me by surprise, but I absolutely love its practical nature. Thanks a lot, this is really awesome!!

[@ktmwalt9430]

Appreciated the Battleship New Jersey pic @25:05

[@atomikvenum]

i have not a shit clue about anything about propellers or boats, but damn if i wasnt glued to the screen for ep 1 and 2, as soon as i saw 3 it was a must watch! thank you for the time and energy you put in these videos dawg you deserve success frfr (my neighbors can hear me audibly cheering for propellers that beat the base lmao)

[@allencloud5342]

26:02 The dog seems to be enjoying life ^~^ That made my day

[@StormBurnX]

I think that autonomous solar powered tugboat was one of the first videos I saw from this channel. Absolutely loved it.... even though I live in a desert!

[@HuierWone]

Whoa! Outstanding sequence of research! You are only posting films on a casual basis that include significantly more study than many bachelor theses combined.

[@coryernewein]

I would rework the hull to accomodate the camera internally with a window. I totally agree that your little camera rig is totally adding drag and changing the images vs the test results. Awesome series🤙

[@solandri69]

Interesting that the top prop (Friendship Systems x Airshaper) matched my first gut instinct when you started all this. Straight blade near the center where the blade speed relative to the water was slower, swept blade near the tips where the relative speed is higher. Also, most of us are used to car motors, where we (mostly) don't have to worry about the motor's peak efficiency RPM. Because it's connected to a transmission that tries to keep the motor in or near that peak RPM range regardless of load or speed. So a boat motor (or plane or RC vehicle motor) introduces new variables which we're not used to from driving a car.

[@GoldenCroc]

Funny you should say that, because even with the transmission, car motors are rarely kept at the best fuel efficency range. Throttle opening is much too low and the rpm is also also not optimal, if one thinks about least fuel consumer per watt output. The ECU does what it can of course, but there are significant gains to be had. However, because of how people drive cars and customer demands, there really is little other choice. In general a much smaller capacity engine would be beneficial.

[@-B.H.]

Well done for the entire test series! It was a joy to watch even for someone not part of this particular hobby space. Also the static thrust cavitation view was pretty awesome!

[@goldenmongoose1717]

what I love is that you keep going above and beond with your testing

[@akwamarsunzal]

What a great series! I have absolutely no idea what you are talking about and, really, no interest in props, but I have absolutely loved this series. Great job!

[@sea2side]

I have no rc experience but like your presentation and science... this prop test series was educational and kinda fun, thankyou

[@nodustollens9183]

your commitment to data collection is impressive, and produced some really interesting insights, cant wait to see more if you do this again!

[@fastmatt711]

Super fun to watch! I really enjoyed seeing the variety of props tested as well as your commitment to capturing good data. I’d love to see a series about ducted props (Kaplan propellers and kort nozzles), as well as submarine style props, which must have some wild engineering and would be cool to explore in detail.

[@runescapebanker]

The lengths you go to w the testing, esp the noise, is truly great. These are awesome vids!

[@twinjuke]

Noctua would appreciate your enthusiasm. ;)

[@mycatistypingthis5450]

This was a great breakdown, I enjoyed it a lot. Now I don't have an RC boat, but I just enjoy the thoroughness of the whole project.

[@simonschneider5913]

this is the best thing in terms of research ive seen in a while. methods and transparency: top of the pile! please keep this going!!!

[@cadsonmikael9119]

Man, this is an amazing series. Like just getting the sense of what is most efficient, low noise and all other fundamentals beginning designing propellers. We had a 10kW motor with a b-series prop on test. I started designing a prop very like the spanmaxxung but with 5 blades and whoa, the system efficiency just went up by 30% on our first try! Now we "just" need to get rid of some apparent tvc.

[@robertstark3326]

Once again, you have out done yourself. This was such a huge amount of work that you did. I love your ability to see the beauty in those vortices. I used to be involved in this collegiate solar/electric boat competition called Solar Splash. There was a boat from Kanazawa Institute of Technology, Japan that was a hydrofoil. A truly amazing design and its propeller was very much like an airplane prop. They won the competition that year.

[@YarikJoestar]

I had no idea I had a tism until this tickles it.

[@GohanKanor]

This proves he is working with us to create the most advanced solar-powered tugboat to date.

[@dootanator_]

Duel bladed props cause a lot of drag from creating vortexes from the large gat in between the blades.

[@tomasreznicek8086]

Ah man, the bending! The bane of my existence! Maybe 4 blades would work better, to split the load between them and reduce the bending, but whether it would be more or less efficient would probably depend on the motor. But no matter, this was the first time I did this kind of CFD, and I learnt a lot! Luckily, thanks to this competition, I have plenty of data to validate my CFD against, which will allow me to fine-tune my simulations further, and next time I'm coming back for revenge! ... maybe you could get a metal 3d printer for the next round? :) Anyway, this comp really was a blast, and I couldn't wait for each episode. I really hope there's more to come in the future, there's more than just my reputation on the line!

[@fxm5715]

Always love your bespoke RCTestflight tunes. Sweet harmony.

[@securus777]

Your videos are awesome man. Thanks to everyone who worked hard on the designs. Thank you for being so committed to getting as accurate results as you can, even to the point of rerunning tests and discarding what was probably hours of work (the underwater sound). Thank you!

[@GraceMcClain]

Can't believe it's been nearly 4 years since the towing video. One of the oddest, out of my wheelhouse subscriptions, but definitely one of my favourites.

[@kdknitro]

I used to be a marine tech and really enjoyed this series i also learned a good bit more about props from this. Its funny that the boat you most see adjustable props on were normally sail boats to gain better sailing efficiency so that the blades could sit perpendicular to the flow of water making less drag. Like you said most boats are using the fact that an engines power range is normally at a certain rpm so they shoot for that rpm for the props specs. Good series man keep up the cool and interesting videos. Who knew that a kid making bomb dropping cargo condor would evolve into the stuff your doing now.

[@tullgutten]

The underwater noise of the props is just amazing how silent some where after the first ones!

[@outputcoupler7819]

Holy crap, the lake warmed up enough to get in? The bodies of water around here make me nervous. Cold water shock and _really_ deep water is a hell of a combo.

[@HellaNorCal916]

I remember the tugboat...😂 It definitely looked sketchy at times. I've definitely enjoyed your videos over the years. 👍🏼

[@mattmccutcheon8675]

These are very interesting videos. I hope you try the higher wattage and have new submissions. Would be very interesting to see how the winning designs change

[@wewerewildlife]

Nice vid 👍. Once you're done with underwater propellers, try drone propellers!

[@Proxtor]

I wonder if you applied on the propellers a hydrophobic coating or different types of coatings and texture will have any performance increases. I know on hulls it doesn't, but on a propellers it might actually be a benefit....

[@markg1754]

Your kayak tug is my favorite video! It's what introduced me to your channel. I would love to see a revisit implementing everything you've learned. Keep up the good work!

[@erikh8685]

Those static thrust clips with the APC prop look so cool

[@guyskeer5411]

Fantastic Techy Sea Chanty! This from a United States Merchant Marine Academy Engineer who Sang in Barbershop Chantys for a Number of Years! Too Fun!

[@titusm9837]

I watched the competition with lots of hope. This type of content has lots of potential. I consider testing some of the propellers on my airboat

[@anoirbentanfous]

Please continue this approach; I believe it can lead to the development of the most efficient propeller, potentially revolutionizing maritime transportation.

[@cgsrtkzsytriul]

this has become my favorite series on KZbin

[@semiperfekt]

Great videos! One propeller size fits most is basically the big take away here. There is apparently a reason why most propellers for boats looks the same when they're for similar sized vessels.

[@martynridley3671]

I've really enjoyed watching the whole test and your songs are fantastic!