MIT Thinks you're STUPID - Toroidal Propeller Snake Oil
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- เผยแพร่เมื่อ 6 ก.พ. 2023
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While they are very similar, fans and propellers are on opposite ends of the spectrum for the fundamental compromise of "moving the air" vs "generating thrust". The confusion for laypersons is the impact of Newton's Third Law on both propellers and fans. If you step back and think about it, you really don't want your fan blades generating a lot of thrust, you want most of the energy going into the motor/engine to be used to move the air. For the propeller, you want as much energy as possible generating thrust, and only push the air backwards as little as possible. Propellers use their shape to generate "lift" in the direction of desired motion (thrust). I know a lot of people will argue with me that propeller = fan and fan = propeller, but for those people I really recommend researching the topic. There is a misconception that propellers primarily move aircraft by pushing air backwards (downwards) against the relatively motionless air behind/below the propeller plane. While there is some of this action going on, it is not the primary mechanism for generating thrust (lift in VTOL drones). There is an enormous difference between propeller design for water applications and air applications. There is very little that can be gained by direct comparison of the two applications by inspection and "common sense". The idea of toroidal propellers for drones, or aircraft is interesting. From what I've seen on other videos, nobody is publicly disclosing a truly engineered design yet (if there actually is a feasible solution). It is well known that the noise from drones is primarily due to the parasitic vortices formed at the tips. Theoretically, if you could eliminate these parasitic vortices, the propellers would be quieter. There is a lot of engineering between that statement and reality that doesn't appear to have been successful. As most readers on here know, the primary considerations for drone engineering are all centered around power-to-weight, payload size, and battery life. To the extent that a quieter propeller design does not compromise one of the critical considerations, it would be an exciting development. While Dr Quad is quite dramatic in his presentation and seems to have an axe to grind with institutions of higher learning, he is correct in assessing that there is NOTHING practically useful in the MIT video. There are 3D designer/printers who are attempting to crudely create physical propellers based on the concept, the reality is that to get to a better propeller design, both static FEA simulations on airflow and FEA simulations on structural integrity need to be ran iteratively to converge on a design that optimizes thrust, noise, and structural integrity. The 3D printable designs that are available and being made in workshops is not a "better" propeller by any measure of practical working drones. From what I've seen, the available designs are just inefficient variations on regular propellers. I'll continue to watch this space, but for now there is nothing useful to see.
said it better than me. And after all this time we still don't have a toroidal prop on the market.... They got the money and moved on because they knew it was a waste of time.
The axe I have to grind with higher education is "betrayal". Because I truly revere and believe that higher education is the way to push society out of darkness and into the light.... But REAL education, the true pursuit of knowledge. What we have now is a perversion of something sacred, and it angers me deeply. Maybe this was just the straw that broke the camels back.
@@33rdframe Yes, this type of prop may not be on the market for drones, but it has been on the market for boat propellers, with PROVEN results. You sir are another liar to the masses only to increase your own popularity. You should be ashamed, and the fact that you're not shows how poor a person you really are.
I AIT READING ALL DAT🗣️💯
Wouldn't moving more air equate to more thrust? Obviously i am not a Mech Eng.
@@walter6574 It's not intuitive, and I've never seen a simple explanation. The closest thing I know is to realize the thrust created by the wind passing over a sailboat's sail is the same physics as a propeller spinning in the air. The sailboat is not pushing the air backwards, it is the difference in air pressure in front vs behind caused by shedding vortices off the trailing edge of the sail. Understanding how sail-boats can tack upwind is helpful in understanding the difference between fans and propellers.
Todays challenge - tell your audience you don't understand something without telling them don't understand.
Congratulations, you succeeded.
You may want to watch the whole video.
Found the guy who didn’t watch the video. You must be from MIT.
Finish the video before commenting
Feel free to post all the evidence proving him wrong🤷♂
Noise is more than just a dB rating, there’s many sources of noise and how ‘annoying’ it can be: Tonal
Broadband
Loading
Thickness
Roughness are all different types of noise
Too true, I just got a new "quiet" refrigerator that has a high-frequency 'warble" to the compressor that mixes with sounds from the TV and is really annoying. The low hum of the old one was easy to ignore and on its own was somewhat restful.
True about noise. Just little quiet from conventional propeller.
However, more surface area, more blade, more weight, more material, bit expensive, limited rpm, hi-rotational mass, more amp draw = Inefficient.
They did a test underwater of the MIT design and a standard design. You can see how they made the MIT one sized to the standard, even same materials. In the video, they're going at the same rpm and the MIT isn't making as much cavitation was the traditional design. That's what makes is new development so amazing.
Okay, measure any of those 5 things, and see if that's the type of noise theyre referring to
This is at least partially accounted for with the ‚A-weighting‘ meaning they used dBA. Which are somewhat weighted after human hearing.
"A-weighted" is not like, a singular weighted noise. There are two commonly used spectra for measuring sound intensity. A-weighting is used for most sounds, and C-weighting is used for very loud sounds like jet engines or heavy machinery.
He lost me when he didn't know that "A weighted" is a thing. Also, I was in California in 1982 and saw toroidal windmill farms with hundreds of windmills. There must be a reason none of the new ones are designed that way. Regardless, MIT did not come up with the toroidal design.
@@bobgraves5833 He lost me way earlier than that.
Drones routinely reach 90-100 dB so you could use either really.
The lack of details is pretty sad. The bright side is that there's so many people looking into this now that we'll all know if there's any value in this design very shortly. It's at least been inspirational in that sense.
Yeah, and maybe some really new designs will be developed as a result of people interest into this
It's OK. The lack of any details is made up for the the amount of presumptuous misinterpretations and basic ignorance. Gotta get on that hype-clout-band-wagon though. It's working for him, every time he picks up a trend to make a video on he gets more hits.
Over his last 30 videos, if he didn't make the a video about the highly trending subjects (basically those TH-cam copy hype-train subjects that there's always way more videos about than really required) then his average views per video would've been around 235 views. But throwing in six 'hot topics' (two of which, this video and the GPS rescue video, far more successful than the rest) has increased that per video average by 1,028% to an average of 2,653.
And taking the 'challenging view' or going against the trending opinion creates a volatile and 'controversial' comment section that will certainly help with the TH-cam algorithm.
Good for him.
Personally, I can't stand the format of this video. To me it's just constant interruptions every two-to-three seconds. Could've easily compiled thoughts and addressed just as many points less frequently. Fingernails on a chalkboard this video. Unfortunately.
He didn't even show the actual research paper, that was a freaking highlight pamphlet he was passing off as the research paper, he's the one that thinks we are all stupid and you'd be an idiot to fall for his BS.
@@crobnz I just stumbled across this video and I have never been so annoyed by a youtuber.
This is quantum computers and "alters" all over again.
People on youtube putting in clickbait for views.
One more reason you can't trust anything on the internet.
"What kind of electrical power are you taking about? Volts, amps?" Seriously? Electrical power is measured in watts, this shows that you really lack understanding. And yes this wasn't made as a research paper as research papers are public domain. They are looking to make money off of this. This tech really is an improvement, your going to hard into details that don't matter or were simply covered poorly. Improvement also doesn't mean night and day difference.
On a boat, it is like 20-25% fuel savings for the same speeds. So on the boats this is a game change. On the plane, I am not sure.
Honestly I just see this as a more expensive technology in terms of material (more meat for those blade profiles) and manufacturing (complex shapes). Not really sure if those blade profiles give you that much improvement to be considered an actual advantage. In fact, I have the idea that some energy is wasted due to Coanda effect which could make air go in circles along those funky blades. But it's just my afterthought.
Also, I think he meant "electrical power" as a broad term, not really the power in Watts. And besides, Watts are not the only unit for measuring power, as an example you can have Volt-Ampères [VA] which you can find on many appliances due to inductive/capacitive power.
@@millanferende6723nope , there is a video on that also
The Toroidal boat propellers are pretty neat just from the efficiency gain. I would assume there would be some applications for them for drones if nothing else then to make the propellers more resilient to impacts but I would assume you would need to design them with a much different pitch to be efficient in air.
I have 3d printed some for my old tricopters I gained 13 minutes of flight time with them on.
Aren't they 50% push down?
I installed a toroidal Sharrow propeller on my boat and improved fuel consumption by 25% at mid range operation, achieve cruising speed at lower RPMs and reduced noice significantly compared to the old traditional prop. I have no clue how this style would perform on the air though.
Funny thing is they are so easy to break on drones... actually will snap the ends when I throttle up too hard. These are mold injection props too.
Dude, you so angry!!! This is a hobby for us, and with 0.5 cents of filament we can have fun.
Lying in a research paper is a hobby for you? Hiding details of your study to win millions in grants is a hobby?
Anyone in their right mind should be angry.
@@malcolm_in_the_middle I do agreed with you but took me 5 hours to print the toroidal prop, installed in my quad and find it up that is all a scam BS. And I will spell out this idiot’s from MIT for making a big claim out of a scam.
look at the bright side , they release the publication so others can print and test it out them self to further verify claims. im printing and testing one my self too.
Sorry buddy these are already in production and their main point is to distribute wingtip vertices and cavitation across a broader section of edge. They are not magic but they do work. Check into marine application.
I don't think his problem is with the concept of toroidal propellers itself but with how poorly the process of research and publication was displayed in this case. The fact that they already serve a purpose and have been around for a while is more in his favor than against it
People have tested on other channels and it is different, the frequency is different, handling on a quad is different the useless outer edges may be resisting drift from straight, and because you have more surface area it is less efficient. They have had toroidal propellers for a long time on larger planes, the difference is the closed shape that probably increases the stability (lift surface warp and bending) of the shape in lightweight materials, this design seems to be aimed at drones.
I wouldn't be surprised if they are quieter at the same RPM & size but there is no way they would be quieter at the same thrust.
The printed fan for noctua channel showed they are quieter >5000hz so it would depend on your rating...
th-cam.com/video/4ImeOKgD_Dw/w-d-xo.html They also had half the airflow of the Noctua at same rpm/sound.
They will be a lower frequency, they don't have the same tip velocity and flow characteristics. They may be a little quieter... probably not by much though.
@@soggybiscotti8425 I'm thinking that by the time you increase the speed/size enough to get the same thrust they will be noisier. The MIT testing looked like it was same size + same RPM (they gave zero data for that) and it was still very close for noise, no data on thrust either which makes me think that there is just no benefit and they know it.
@@samheasmanwhite yeah that's pretty much what I'm saying.
There will be a very minor difference in the high range, as you no longer have prop tips that notoriously produce shock tips, bjt instead have a rounded tip. This should produce a lower hum overall but it won't be significantly quieter at all. Maybe slightly, and maybe a tad lower frequency. Nothing of significance though.
It’s not “a weighted” noise. A- Weighting, as opposed to C weighted, is a deciBel measurement that is a frequency profile applied to the measurement to make it match how our ears hear different frequencies vs a microphone. Not arguing your other points and additionally, these designs will have a lot more inertia than a standard prop making them slower to react on a drone that needs to change the motor speed very quickly.
Thank you for correcting me. Yes I didn't fully understand than but I looked it up and you are correct.... It still doesn't provide any actual data but it's not as ridiculous as I made it out to be
@@33rdframe And electrical power is measured in Watts, not Volts or Amps.
@@GavinBath p=vi . i mean you are splitting hairs
@drquads5589 how many split hairs accounts for the time value relationship to power?
@@jerrodbrown5475 listen bro I am not here to mentally masterbait to make myself feel smarter than others. the proof is in the pudding. do you feel that "scientific paper" was adequate or not?
And the toroidAnd the toroidal propeller has a problem that no one mentions: it is quite difficult to make an adjustable pitch screw out of it. If at all possible. Which narrows the scope of its application.
Reminds me of my experience with Academia:
1) research goals where unexpected results are a reason to get yelled at and sweep them under a rug, even if you stumbled on a cure for cancer while researching non addictive painkillers...
2) You have 4 years to get your results and no one cares how you get them...
3) All that matters are the number of publications, the prestige of the journals, and the relationship with your sponsors, and collaborators. Thus, even if you submit the truth, it will be rewritten in order to keep the sponsors happy and don't even dare to think of starting a beef with another research group by proving their publication to be faulty...
Sharrow filed for patent on their boat prop in 2013. MIT guy is definitely suspect for claiming he came up with this idea organically. Now, maybe he improved the design and performance for air but he is definitely waiting to cash in with DoD military applications.
You just hit the nail on the head
I read an article a while back about how the boat prop was initially designed as a drone prop. But it didn't mention why the company didn't pursue drones any further. I'm really curious to know why that is. Maybe there was more money in boats or it just didn't work out.
@@jakobseiler this is interesting can you link that?
@@jakobseiler The difference in performance vs conventional propeller is probably due to the different density of air vs water. Sharrow describes drag as the difference between the distance moved in a solid (theoretical) vs the distance moved in water at the same rpm. Maybe the benefit in air isn't as great as the benefit of this construction's performance in water?
@@jakobseiler I would venture to say that it makes more sense from a business perspective to make a product that cost 5k for a recreational boat prop that you can't make at home over a $10 drone prop that can be made on at home on a 3D printer. Nevermind the license fees that would come if the DoD and the maritime industry would pay to outfit ships with these style props. Just imagine what the navy would pay if a prop was say 15% quieter on a submarine.
One crucial point I have not seen discussed about this kind of pop is that shedding the tip vortex along the blade, instead of only at the tip, is that it will inherently produce less thrust (Since the total circulation at every cross-section of the blade is reduced). I believe that's why the boat prop uses a staggered design, increasing the "blade width" and compensating for the aforementioned effect. Maybe it is possible to design a good, well-optimized, toroidal prop for drones, but since these have been around for some time and have not seen any commercial use in aviation, I highly doubt it.
So they are more benign propelers, a d not actually effecient
Should look at helicopter rotors not fixed wings. Modern helicopter rotors are super quiet compared to helicopters designed in the 50's and 60's and it's because rotor blade design has advanced a lot since then. The local PDs chopper is so quiet that the tail rotor is actually louder than the main rotor and you can only really hear it when the outflow from the tail is pointed in your direction. Until it's almost directly overhead it's almost unnoticeable and it's quieter than the traffic even then. From what I can see on modern helicopter rotor blades the tips are swept back and curved down like a sort of winglet on the end of the blade but there's probably more to it than just that.
Ok, I can answer you about that, I was watching and thinking how could do this usefully, THEORETICALLY you could increase the blades and staged them as you said, if the calculation is done right, the second stage could improve the airflow increasing the thrust, somehow similar to a counter rotating prop, but the shape of the toroidal needs to be optimized to work as intended, since it could increase drag, change torque characteristics etc.
That said, I will jump forward to my expertise, production, if you can, answer me what kind of material and how would you do that prop? You can't? Neither do I, the complex shape needed to be analyzed for how would it handle stress, heat, vibration and so on, the connection between the first stage and second stage blades is the worst part, I don't have any idea how the forces works in that area and how the casting or molding would be done, and as we know from the tips of normal propellers, will definitely be the worst, and we can't forget the weight and balance, which is totally different..
In conclusion, could be indeed made, but the development is too costly for the uncertainties of the benefits, also the production and maintaince won't be competitive.
Just doubling the number of blades and prop density does cause a big shift in the props efficiency, RPM and tip speed ratio. You would need to check on the Huetter prop density diagram first before even considering the tip vortex effect.
The key thing here is understanding Betz limit. At like 55% efficiency a convetional prop is as close as you will get to 59.3% theoretical limit. You basically try to magically optimize away the last 5% aerodynamic loss. That energy splits between friction heat and noise. So at 5% that crazy low compared to all other designs. You can maybe squeeze this by 1% or 2% if you all other sign the same. So that why no one really cares to try do that.
The noise effect is tied to speed of sound barrier effects - these to strongly depend on RPM and tip speed ratio at pro size.
Regarding a boat prop we speak of caviation - a theopretically similar barrier effect in larger sense, but totally different in detail. A much different challenge in a much different speed regime. Occurs in an entirely different RPM and tip speed regime, but Betz limit stil does apply. Boat impellers mostly are impulse driven not lift driven design anyways and should not be compared directly to lift based props/turbines. Comparision would always be shown on the tip speed based efficiency power curve turbine comparison chart. Omitting this essential key claims reference is the classic scam sheme on any turbine design "perpetuum mobile" magical energy / efficiency claim.
A boat prop never runs at the super-optimized efficiency of a container vessel, because fuel efficiency of boat props never was any real concvern for leisure boat owners in the first place. We speak of rich guys just guzzle a small thing from A to B. We don't speak off 15K TEU cargo going around the globe on a customer paid budget for a month.
So we basically do not know what that leisure boating props starting efficiency even was.
Even if this gets debunked by pros quickly, this pump & dump will still catch and score with some stupid money fools.
It is the perfect psychological design targeting arragonant half-rich smart assy people with leisure boats.
Doesn't reallly matter what fluid dynamics experts do think or write here. We just fuel the controversy on these bets driven by greed and fear. This is Aerotyne Industries of The Wolf Of Wall Street.
@@atomicskull6405 would this be advanced form to the effect of a nonlinear "twist rate, "
First hand experience with award winning young engineers/scientists fresh out (or still attending) MIT who collected investment money for their startup using nearly identical media to what is being discussed here. ZERO data...
These young/bright people were awarded and praised for very loose conceptional, yet thought provoking work - The educators and mentors had failed them here - They were dissuaded to work the magic that IS science, and instead encouraged to generate social media presence, hype and branding at all costs. Most TRULY believed they were but ONE small step away from full-scale production of a world changing product.
I am sure most of these people were able to get past such a setback so young in their careers, but it definitely makes me a little sad.
You saw it for what it was as well. Yes it makes me a little black pilled
@@33rdframe Always self check to see if the square wheel law applies to your passion project :D Thank you.
Never assume you are the smartest person in the room. If you find yourself in many rooms filled with people proclaiming YOU as the smartest person in the room - Walk away. You have much more to lose than gain. In the case of many of these young minds it's very clear. MIT and others have perfected a formula to win these awards at great cost to the students receiving them.
This did get me excited, so there is certainly a positive take away here!
@@opteryxair I think this is invaluable wisdom for young minds. I did the square wheel thing with my first design and thankfully I have friends that told me how dumb it was haha
Ha e you done any scientific lab research comparuing them, I guess if in 30 or less years if the world is still around, amd the comercial flight industry uses this in turbine design, what would that mean,
@@ryanbeard1119 the just don't flow. Sharrow prop slings something similar.
How much do want to bet the "Doctor" here is one of those guys that claims Einsteins Special Relativity is garbage?
"I am making my video with a clickbait title, in a sarcastic style, where I call other people stupid and laugh at them, therefore I am 100% right. No, I did not conduct comparative tests in a controlled, maybe even blinded conditions, but you still must believe me because I speak more fluidly than the original presenter".
You noticed that as well. Kind of funny in a sad way.
Sometimes things need to get called out. I think these propellers were around before.
'Dr Quads' needs to see a real doctor about his personality disorder.
And people who were skeptical about the original are ironically not skeptical about this
And turning out to be the stupidest person ever! Not knowing what power is, is definitely so low. Btw, it is measured in watts.
I'll admit, I fell for it so easily. If I had just broken down the MIT video, I might have seen the red flags. The tests from other youtubers are quite revealing, and is why I checked this video out. Great stuff! I will watch the community's efforts on this design with hope.
My first introduction to this was the guy that tests comupter cooling fan blades, he found pretty much the same thing. My initial reaction was like "oh hey, that looks cool," then "oh darn."
What props are the TH-camrs testing with?
Because I am a perfectionist I bugged the hell out of HQ prop over my 3.5 inch drone... And to their credit the engineers sat me down and walked me through every question I could think of. And one reoccurring theme was weight. So I knew the second I saw these props they would never be as efficient
@@33rdframe If they produce less drag (vortices, cavitation, etc) and consume less energy per unit thrust, then yes, yes they are more efficient.
No one at at MIT claimed these props were for the 3.5 inch FPV tools...
@@33rdframe It must suck to be a perfectionist who is falling so far short of the mark.
Have you seen this guy?
th-cam.com/video/UWoXFdRhPKc/w-d-xo.html
He doesn't claim to be a perfectionist, but damn is way out in front of you.
Seems like it's hard to escape the fact that more surface area = more friction
When designing any kind of airfoil there's always a tradeoff between friction drag and form drag. Form drag tends to increase loading (decreasing area per unit load) and friction drag tends to increase with surface area. There's usually a sweet spot between the two extremes that provides optimal efficiency. It's likely that the optimum loading will be different between a toroidal and conventional propeller. And it certainly shifts toward lower loading and higher surface area if noise is a more critical design parameter than efficiency.
Maybe some type of artificial surface that mimics shark skin denticles would work
Outstanding, spot on hats off to you
Keep up the great videos!!!
I agree for the most part but reserve judgement until I see proper testing from a prop manufacturer. They will definitely be investigating but I do not believe the resulting prop will look like what MIT has shown.
I mean I am sure there is a possibility to gain some tiny tiny benefits from these props.... But you will lose efficiency, power, and handling..
Maybe the best thing these props can be is kid safe... That not totally useless... It's just not a revolution
@@33rdframe How about for large drones used for military and delivery applications? Did MIT ever once claim they were working for the FPV community, "Doctor"?
@@odinata they used an FPV drone directly in the promotional video....
@@33rdframe Do you know what FPV stands for?
There is is no FPV camera on that craft. There is no transmitter, no antenna.
Probably just an early proof of concept, since the lab caters to National Security and Military..
@@odinata what does FPV stand for?
Wouldn't using a 3D printer also make it a bit louder? The grooves running through the air?
Bro.
FOR REAL, how is ever something like a drone going to be quiet? The thing alone without the propellers attached makes so much noise already, no matter what you put up in there is going to be LOUD. Surely it could be quieter than the original propellers, but that's like comparing a gun suppressor and calling it a silencer... ITS STILL GOING TO BE F$@$@ LOUD...
But honestly the new shape looks better and less threatening than the original blades, for that alone I like the new design, if it can provide better deficiency and lower pitch (yet still loud) even better!
Thank you for making this video. So informational.
*"A-weighted" gives the scam away:* you want to follow the energy - but "weighting" means that you have decided to ignore the part of the emission spectrum that contains most of the unwanted energy! Making-things-magically-quiter-by-applying-weighting has been a standard in engineering cheap consumer products for ages - and that's why A-filtering has no place in real science.
I misread that as " a weighted noise"
But now that you have informed me of the truth I see even more how much of a scam it is!
You're right about pretty much everything but I'll point out that at ~ 7:20 where the drone is wobbling, if you look at the trees, its pretty windy.
That is a good point. I should be more precise!
No he seems right about the wobbeling in horizon mode. th-cam.com/video/hby6U47oV_k/w-d-xo.html
@@33rdframe I think you are right. But only in Horizon Mode th-cam.com/video/hby6U47oV_k/w-d-xo.html in Acro the issue is gone. But well, the Video doesn´t show the Betaflight logs :) Greetings from Germany
I would bet the PID tuning is significantly more aggressive in Acro mode which would give it better stability. Ultimately, they still chose a wobbly flight video as their presentation material which seems counter productive.
I think that the one thing that is great about these props is that their design is actually very conducive to 3d printing. The lack of tips makes them print much better. That said propellers are not new technology and they have been being studied for over 100 years.
Wittgenstein the philosopher started out designing propellers.
Okay so I think i found the patent and in the patent pdf there's some graphs with like power coefficient on it and so on. Are those bogus too?
I have viewed several YT videos in which the creator used the MIT data to 3D print toroidal propellers for their drones. I more than one, the propellers were louder than the stock props. However, in one, the creator installed 8-blade swept-back props that were MUCH quieter and gave better performance than stock or toroidal props. So, you are correct. It's a sham.
Great, I have a series of ion propelled vehicles that are patented for having onboard power. MIT claims "they" were first at that as well!
By the way my daughter's name is Zephania. (With no "h" on the end)
I think you did not get that a intern started with FDM printer to rapidly iterated design to see if this new prop design would have benefit. First step. When it started to have good results, they fine tune the geometry and started to use SLS and SLA methods to fine tune the results.
If they just had done all that before starting making marketing videos with bs animations...
lol
@@TheChzoronzon they did all that before, the applied for a patent in 2017 and was granted in 2020. That patent got some info in there. And now they release marketing material.
@@JeromeDemers So we have the efficiency data? Nice!
Can you give some numbers? Trust/wattage, for example?
Or the link to the specs?
@@TheChzoronzon did I say I have the efficiency data? Those props are design to reduce acoustic signature. Nothing else.
Have a look at the patent. Figure 6 "show that prop B160 demonstrate higher efficiencies than the best performing conventional propeller ( SG30 ) " That is line 51 of page 10 of PDF
patentimages.storage.googleapis.com/d6/fe/53/bea4417ed89176/US10836466.pdf
well that sentence at line 51 does say that it's more efficient than conventional prop that *they* decide to test
@@JeromeDemers So no actual data...
Unexpected!! :D
Ey, if power output doesn't mean anything, I can easily design a completely static "propeller" that makes exactly zero noise... I'm gonna call it potato. No, wait...HyperPotato, that sounds waaay cooler. Surely my investors will appreciate the semantic effort...
Tellingly enough, the propeller they compared with is a mystery one... and they show just the comparison, no objective data about the trust nor efficiency nor wattage input... nothing but vague marketing drivel
Dude... are you really THAT gullible?
A paper so incredibly poor and suspicious... doesn't really make your bs alarms ring like crazy? You seem to have some science basic knowledge...why do you cheat yourself like that?
This video popped up right after I watched a video comparing (3d printed) various toroidal fan designs against a standard Noctua fan (YT channel is "Major Hardware") - including a Sharrow based design. Correctly designed ducted fans and therefore propeller are vastly superior in regard to noise, static pressure and airflow.
I also saw a flood of other videos on Toroidal propellers at the same time.
They are selling it hard
Excellent Video !!!
Much appreciated
Whats most important: less risk of slicing vingers than 'normal' props..
Gotta love Dr TH-cam arguing with MIT... Hilarious.
I know , he had to pause while his mom got him some pizza bites from the freezer . MOM BRING PIZZA BITES TO THE BASEMENT!!! IM PROVING IM SMARTER THEN PEOPLE WHO PAYED FOR EDUCATION!!!
😂😂😂
@@tomsgeekygarage2066 eh, he's just up and coming and trying to get traction in all the wrong ways.
Okay Mr Reddit, let me speak your language: your argument is fallacious. It is a logical fallacy known as "the argument from authority". You have not addressed any of the points raised in the video, just "MIT said this, therefore it is fact". Experts make mistakes all the time, and they lie even more often.
Man. This is the coverage of MIT that we need
Don't let this idiot fool you mate, he's trying to pass off a highlights pamphlet as an actual research paper. If he doesn't know the difference then he has no idea what he is talking about, if he does know the difference then he is maliciously lying to you. I think he is the one that thinks we are all stupid...
4 months later and you're completely right and super based.
Love bro
This is why peer review is important, for both the claim and the refutation. I look forward to seeing how this all plays out.
th-cam.com/video/ncvsNz2Mup8/w-d-xo.htmlsi=QcZUI8y9kjpn3jLF
Got my hands on some injection molded toroidal props
lol it's been proven to work on boats...there are successful 3d prints that a lot of people have tested, although their performance isnt as good as normal props cause they're 3d printed, and the designs are still being worked on. I want to see what a factory produced or well produced clean version from good plastic will perform like before I buy or put any time into them though.
The design that's been tested rn by almost everyone is by one guy that just modeled them and put his idea of them on thingaverse. He's already iterated on them several times now to improve them, and they have improved. They're not the actual props that mit made or their design so we dont know what materials or design theirs was exactly, it may be a couple degrees difference in pitch does produce the results that mit claims.
One thing I think that could vastly improve on the design that I dont think the current props include is to stagger the secondary rearward blades and angle them so they're not cutting into the same disturbed air and add even more lift but move the air out of the way for the following blade, which the MIT guys may have realized in their designs.
"maybe, possibly, should be, would be"
No data, no proof. Snake oil. Muted audio.
@@33rdframe lol you have a point, you may be right, I hadn't considered they would be trying to fake this for some reason. I don't really see the motive, the design is going to be iterated and improved on quickly, and is essentially open source because of that. I don't think you can patent all forms of this prop, but maybe?
@@maddercat two words: patent granted
@@maddercat honestly bro, how noone noticed they muted the audio...
@@33rdframe Yeah, but there are details to that, like they can patent their specific case, but if someone comes along and improves on it, they can patent that too right, which will likely happen soon if not already. Patents only protect specific iterations of an idea, not the idea itself.
For comparing things, you can't compare the propellers by RPM really. You should compare them by effective lift. A "Propeller" with flat blades will make very limited sound compared to a propeller that actually moves air. The optimization therefore is noise per thrust/lift, not noise per rpm.
Other than that, i am also stunned about the blatant lack of simulations. Doing a fluid dynamics FEA isn't that hard, especially on those very simple designs volume-wise. *Especially* considering there is already 3d models to 3d print. Getting noise levels there is hard, but it could give info about rpm/torque/thrust and therefore the efficiency baseline in comparison to conventional propellers. Doing simulations for a living, that might be my pet-peeve, but if you show animations, at least show useful animations man!
Apart from comparisons and lack of simulation, i do not think researching various propeller shapes is all that wrong. Obviously the way they are doing it is methodically flawed. But, fluid dynamics is hard. The fact this stuff is changing on motorboats (and commercially viable there apparently, i am not a motorboat guy) tells me there is at least a little bit of experimentation/simulation that needs to be done. Deserves less attention though if there are no real results....
All propellers need to be designed for their particular operational envelope, which includes things like density and viscosity of the medium, rotation speed, forward speed, material modulus, and more.
have you read any of the research papers from other research institutions on boxprops?
Nice breakdown!
The most relevant comparison would be to use the same prop diameter (since that's a practical limitation in real world use) and run them at whatever rpm that produces the same thrust. That might require different rpm but that doesn't matter, what you want is thrust. Then compare the noise and power consumption in Watts.
you are literally better at science in a youtube comment that MIT in a 40 million dollar lab
This is great! You should print a version yourself and share the data 😂
Printed propellers aren’t going to perform as well.
@@ShabazzTBL I mean… MIT used printed propellers
@@petermarin Their machines are far better. Regular 3d printers are way too inaccurate
@@GalacticNovaOverlord what are they using if not regular 3D printers?
@@heavyweather they are. Most of the prints I saw were run of the mill with minimal refining
It's likely the MIT guy is overstating their results for attracting investors, but I am positive they achieved some improvement.
5:33 you can see foam, sound canceling pads there. They can be eliminating more excessive noise than it suppose to have
The golden era of propeller technology has long past. If toroidal had merit, they would have applied it.
Well spoken
The moment I saw this design it came to mind Mugita Takada and Minoru Yoshida "Loopwing" blades design for wind generators which released in 2001.
it reminded me of vertical Darrieus wind turbine 1926
@@jhjliwudgj6655 indeed
Most of the video is a Kickstarter, but the internet got wild because they work already in boats and the noise profile graphs. There are real MIT stuff, plus they are much safer without guards which by itself is already awesome. Yes it's probably mostly for cinewhoop.
For now we have zero data for air propeller. gain is real for water propeller and avoid cavitation.
But you are right it's good for safety for cinewoop.
The efficiency loss seems huge in actual models people have tried. It's poopoo.
I'd compare against a prop printed in the same way with about the same thickness. Also we have so many profiles and variations to tests with these new props that they may be bad but it's still exciting.
I have a toroidal propeller I use to levitate from my work cubicle to the teleportation machine.
Ah! I can see now you are a man of culture 🤣
Bro has “recently divorced” energy
The illustrations at 4:10 look pretty clear and informative to me, and interesting too. I have no idea what you are your questions: Electrical power is measured in watts, (that is, Volts X amps, and amps represent current btw ), this is the only value that matters in that case, and each design show a balance (hence the scales) according to those values.
I should also note that those designs have almost nothing to do with the 3D prints that I have seen being tested on TH-cam...
illustrations aren't information on how it performs.
I saw that toroidal PC fan video one day, then seemingly the next day there were 47 videos of FPV droners using them
funny to watch, funnier to see it flop. especially by students from such an exclusive institute
None of the universities have standards anymore. They are all basically the same with brand names that make some people think they are still better.
The improvement in sound level reduction is an amazing discovery and a significant contribution to aerospace technology.
Most of your complaints are about a video that is just announcing something. It's not a deep-dive, technical review video, it's an announcement video to show the idea. Also, in science "significantly quieter" doesn't mean, YOU'LL NEVER EVEN HEAR IT, it means it's a statistically significant difference. Whoever said "Here's the research paper!" is just scrambling though. Honestly, there's not even an abstract, how can you say that's the research? As far as I can tell there isn't a paper that's been released. They have more information and data and charts on the patent though, and it feels a little disingenuous calling them out then not mentioning that (there's even charts!)
I saw that paper and just figured they were trying to monetize this and that’s why they’re being so vague with what they released. You bring up a fair point but it’s still very exciting to imagine different propeller designs that are funky and weird!
Make them dong shaped and it will be even more "exciting"...
@@TheChzoronzon Only a dick would use them tho
@@MacPoop That's racist!
@@TheChzoronzon Racist? Or sexist 🤣🤣
@@TheChzoronzon Man I left a perfectly good dick joke right there on the table re dong shaped props; 'that would probably blow well'
thank you so much for being the one guy to go against what every youtuber parrots. It happens every time.
And turning out to be the stupidest person ever! Not knowing what power is, is definitely so low. Btw, it is measured in watts.
is knoise from propellers "crashing" air or the actual cleaving of?
I don't actually know
Thanks for this. Necessary content for current times.
Yes, the University money and labor model. Almost as action packed as the aconymed sports leagues.
Brilliant 👏👏👏 went and dug up the paper and then the patent filled in 2017??? Hey? 6 years and nothing, no data of any sort…. Well now. It also references 5 of the 64 Sharrow patents that are the original toroidal props. So the MIT guy definitely knew about them. MIT is trying to sell snake oil here.
Oh and the prop on the paper does not fall in the MIT “patent” at all…. It does infringe the Sharrow patents. I guess that is why the MIT one is dead and not moving.
IP is gross and holds society back
@@poiu477 no it does not, IP rights force competitors to think and make their own advances. If it was not there others would just copy, and it would also remove the incentive to those that can make something new to invest the time needed to do so.
Besides that in IP law, should someone come up with a new improved version of some patented device the patent office can grant automatic royalties to them to utilize the other patent in order to bring their advancement to market.
without IP rights everything would die, including medicine……. Nothing new would be developed ever.
I am actually going to talk about this tonight on my stream. Because it's something I think people get wrong all the time
@@gannet-dronefishing2295 The open source community would like a word with you
@@gannet-dronefishing2295 Nah capitalism in general is exploitative, bad, and hurts development overall. There are wasted duplicate efforts, "competing companies" both needing the same administrative overhead and what not. Perverse incentives where companies are rewarded for doing harm to society, including by flouting regulations and such. it simply is wrong, for the one fact that there are six vacant homes for each homeless person in America. That's wrong. We do not need profit as a driving force and people should not be able to accumulate such wealth as we allow today where not even one's kids could hope to reasonably spend it in their lifetimes. We don't need sprawling mansions and estates stealing the coastline from the people as in Narragansett RI.
Part of that noise is motor sound that comes from the high RPM. How are you going to stop that?
You dont
In fairness, at 4:17 you say they thinks we're dumb when they say electrical powerv with no clarity, but electrical power is measured in some form of I*V (or A*V) making kW.
Oh, also, you ask why they use fdm, that same time stamp shows their saying they used SLA printers to make the blades.
On everything else, yeah, I am gonna agree based on the evidence you have shown. I'll be keeping my eyes open for additional data.
to be very nitpicky:
electrical power is EXACTLY meassured as P = I * U, or in terms of units: W = A * V (kW = 1000 W)
other than that you're 100% correct
Heya Dr Quads! I think some of us in the hobby are just thirsty for anything that is new and innovative, even if it isn't necessarily better! Maybe there is room for new ideas in conventionally bladed props, too.
For sure. If I can find a prop design that is less annoying to the human ear, even at the cost of some efficiency, there are cases that I would certainly want to use it. I am happy that MIT put this out in the public eye. I don't have to give MIT any money. All I have to do is build on the idea, that I would most likely not have come up with myself. But now that I have seen it, I am excited to give it some tests. Refine it. If I can find, or if a fellow fpv maker, in our community, can get it more refined, there is zero harm. This is only good, for the fpv world. If it doesn't suit the application, don't have to use it. If an iteration of this idea does fit into a use case, happy day! But what I love the most about this, is seeing the fpv community get excited, and sharing experiments, successes, and failures. That is what this hobby is all about for me. The last few days have been great for this, and whether these props fall into the shadow of our memories, or they end up coming along for the ride, it was a lot of fun.
no matter what. it is wrong and harmful to the community for trusted institutions to lie and manipulate.
@@Inertia888 I agree to your humbling point. It's free to test it. Mass production and they'll ask for royalties. perks of being first to patent.
But I also agree to DRQ about potential problems with academic papers, patents, claims without peer review. Take internet with a cup of salt coz there's a lot of BS ideas that should not be glorified. I recommend Thunderf00t channel, maybe he can make a video about toroidal sometime.
@@33rdframe They arent, you are just being an arrogant clickbaiter for acting like we are their target audience and they are trying to sell us something. Get over yourself.
@@kautionfpv so you are ok with them lying and manipulating others just not you?
FDM is capable of stronger than SLA, so you can reduce cross sections and get closer to ideal geometry whilst maintaining durability. Possibly a weight saving due to increased strength, too.
You are just incorrect entirely.
Power in verses thrust and noise data?
Anyone noticed the props used by this Zipline company to deliver medicine in Rwanda?
If the footage is genuine their props are truly whisper quiet.
I've flown 2, 3 and 4 blade props.
More blades and a gentle pitch on the prop is what makes it quiet.
At 5:22 you can see the Mic next to the 2 blade prop. No Mic on the other.
Low pitch, low rpm, low thrust, low noise :)
i should publish my 'paper' on a vibrating wing design that just moves an air foil back and forth to create lift.
So wrong
@@odinata saying somebody's wrong, and not having any resources to back up your claim does not make it valid.
In other words.... if you want people take your comment seriously, you need to explain yourself.
I don't know how astronomy has anything to do with flying.... I have at least 7 years of prop changing experience and design my own from store bought props *and* *I* *show* *how* *I* *did* *it* so I may not be Gemfan or HQ Props... But I'm not new to this.
@@MadDragon75 If you want' people to take a conspiracy theory about a new prop idea that isn't even in production yet, why don't you go ahead and PROVE they don't work?
Hmmmm?
Why are you whining and crying about some MIT students making their research publicly available for free.
Take some time to assess whatever is going on in your personal life that is causing your project like this.
Ah the "you got problems because you care about stuff" approach. Sorry but nihilism isn't suited for me. Better for boys who never grew up and take on personal responsibility
@@33rdframe you’re just too dumb to understand the paper
@@Delouser69 yep. i cannot understand bro science
"MIT Thinks you're STUPID" well...they thought right
There are no any papers to read? It is all based on small video?
So.... You're harping on shoddy research on the part of MIT, then admit that the extent of your research is watching promo videos and looking up one paper? You know there's an entire branch field of research into toroidal airfoils, right? By the way, watching videos is not Occam's Razor, it's lazy. OR is the simplest explanation that ACCOUNTS FOR ALL OBJECTIVE OBSERVATIONS. And where is YOUR data on the anecdotal evidence of home hobbyist's failures with trying to reproduce the results? There are plenty of papers AND videos that demonstrate the differences between traditional and toroidal (not toroidial, as you said) props. If you want to refute the science of an entire field (not just one MIT team) you need to bring better science. You didn't. Watching videos is NOT research. The research is digging deeper and putting in the work. But hey, gotta get them youtube views, right? So, if you can't be exceptional, be controversial. Channel blocked.
DrQuads is the guy who never got any education and thinks he knows it all..“cOlLeGe iS a sCaM” archetype.
A bumbling TH-cam oaf.
CHANNEL BLOCKED
somebody is mad that he makes good points. How is he alone meant to compete immediately with what is supposedly months of research from a small team? React to BS claims first, research comes later. If they refuse to provide their own data it is on them to prove their own point, which they have not proven. You are a child.
Definitely not snake oil man.... You're looking for things in the data under the assumption it was written for you and your interests as opposed to what is being studied and discussed in the paper...this whole deal with quad propellers are just a use example....the math and physics are solid, the experiments (yes, there are many other examples other than this video) are solid, and the results are solid..... I think you might've jumped the gun just a little bit on this one man. Good video though.
One quick observation: Just their "dum duh duh dah duh duh dahhhh" background music makes it all feel EXACTLY like one of those half hour long TH-cam ads selling "perfect" chef knives that are "making chefs ANGRY all over the world!!1! BUY ONE NOWWWWZERSSSSS"
Hydrogen cells, lol! Yeah, I didn't even bother with the MIT video and now I'm really not sorry I skipped past it. Doesn't matter anyway since the only way I'd ever head toroidal is if I could print them myself, and then we're talking super low cost for a test run anyway, no big. But before printing them, I'd do what I already did - watch the results from people that already printed them. So far, they do reduce higher frequency noise but that's about all they do. They don't make it faster, they don't make it fly longer, and they don't rain gold dust down in the prop wash nor make coffees fall from the sky. So... it's a thing to try if I need an easy to print prop, but it's not gonna change my life. And that's that.
Lets see what AI has to say about the history of those : " The development of toroidal fans specifically is attributed to a German company called ebm-papst, which first introduced the technology in the 1980s. The company patented the design and began producing toroidal fans for a variety of applications, including computer cooling, telecommunications, and automotive ventilation systems.
Since then, toroidal fans have become increasingly popular due to their compact size, low noise levels, and high airflow rates. Today, they are used in a wide range of industries, including electronics, HVAC, and automotive, among others."
The reason I loved watching myth busters is they made an honest effort to prove things wrong or right. We can all do things that are easily criticized and can be done better, but be a good person and do something that actually can benefit us by testing things. Even electro boom takes the rants and performs actual demonstrations. I might actually subscribe then.
Wait so you want me to do a scientific experiment on how they didn't provide any data? In order to do that I would need to recreate the test entirely
Unfortunately I am not some MIT rich kid and I don't have month of time to devote to a square wheel
other channels on youtube are already testing it lmao
@@deathpony698 Can you refer me to those so I can watch their videos instead? I'm hoping their testing will come with some data.
you hit the nail on the head. I have now seen multiple videos of people who 3d printed some of these and put them on there quads and flew them around at VERY high RPM pulling some very intense maneuvers. they are not going to make the noise go away, but it does change the sound profile enough that it would be harder to hear farther away. i feel watching this video the guy has his mind made up and is just going for the views. here is a a fun example of a noise profile vs raw Db readings.... power supplies in your PC. some are quite, some are louder. would you rather have a quite one that just makes a little bit of fan noise under load. or a ULTRA quite one that is able to keep the fan profile low enough it is not able to be heard under load but omg that coil whine under load is like a knife in your ear drum at that frequency.... yea, they both quite, but that one sound man, like nails on a chalk board.
@@33rdframe too much yap yap. Thats why i prefer other channels.
Criticizes scientific institute - in a completely unscientific way. This cannot be used for anything.
proof is the burden of the one with the claim
...lets go ahead and look at those papers.
Expecting well represented data and non bias video evidence is totally unscientific and unreasonable.
@@CG-un4tr there is no data to look at!!! Wtf lol. That is the whole point
So how, pray tell, ye smartest man of all men.... How would I go about scientifically testing the data provided by MIT in a scientific way... When there is no data🧐
Even as someone with a very loose understand aerodynamics one look at the Toroidal and you can see that it's a lot larger than a normal prop.
How would it even turn without adding a lot of extra power?
in fact MIT doesn't think we are stupid THEY are actually just stupid, sincerely :D
After a few days chewing on tihs, it feels like the statement from the people that represents why this got so popular is that drones are way too noisy, and it shows how quickly we are to jump on potential to solve that issue. You are completely right though, no hard data shows there is lack of proof of it actually working. Why didn't you just go ahead and address what was on the patent? I feel like I am commenting blind. A "trust me guys" statement on such a damning video, well....
They didn't say the final version was FPA, he said he had interns working on prototyping to test concept. As you can also see they were try blades while the end version were double.
Which from what I am seeing most of the failures of the net are using triples too. But I have been arguing with those people as well, because they are assuming they can just roughly draw something in cad and expect it to be conclusive, and they too don't use data, it is more like what model of drone it is at best. Which to a layman means nothing.
The point to which I was arguing is that the geometery is everything, that includes the chord thickness that would need to vary. Propellors are essentially little wings, and to just gloss over the years of development over prop technology is a huge mistake. You can't just stick onion rings on some random hub and expect it to do anything.
Using the sxample of the water ones, that too peobably went through a ton of iterations, and it is pupose built to be efficient in that application, as these propellors need to be as well.
Torodial needs a bunch of refinment I am sure, just like the propellor when it was first patented. I am sure they don't want to give too much of that away but still we are talking about a r and d lab that showed enough progress that wanted rewarding. Again though IDK what the reward is, and what the data is on exactly what it is for so that is speculation.
But what had me excited was there seemed to be an innovation that helped reduce some of the highs and lows of the frequency which I do know matters a lot.
I also want to point out that I noticed that the side by side comparison you can clearly hear that the Tor prop winds up slower but as soon as it gets to the same speed it sounds louder. But it also looks like the prop used there isn't the blue version.
It is funny they mention the tests of the military, should say all you need to know because if they didn't make it work, it is highly unlikely to work. I know for a fact they were doing everything they could to reduce prop noise, and it was over a multi decade need. Vietnam they had some of the quietest props ever and it was more about controlling engine noise so they buried the engines in the feselage and used a huge driveshaft. If you watch propellor for submarine videos you will also see that there has been a lot of advancement in the feild. Usually those are hidden from the public until way after they are replaced. There is a delicate balance, and they have plenty of data on it.
For drones more needs done on reducing vibration and engine noise before we would see real benefits of these props. It is interesting the dude was working on ion propulsion and gets a reward for this afterthought.
Glad you made this, hope that the feedback prompts better data to be released.
Your thoughts on the geometry of the props are the same I got after viewing all the attempts people were making, I absolutely agree. Like the current boat prop that has an intrinctate 3d shape, the one for drones/aviation should be as like, they need things as variable chord/angle of attack or just a twist in the "knot" shape (imagine if you look the prop from the side it'll be more like a horizontal 8 than just a flat shape). However, more surface adds more drag and that's where I'm not so sure about efficiency.
@@ivoxx_ Yeah exactly, I would expect the secret sauce is all in that delicate balance, which is most likely why tri didn't work. Essentially they would have to perform only better to 4 blades, though toward the end those curves will need to be perfect to make it work. Stability stems from that. I have just long studied wings and stall characteristics but I would hope that with the award more attention gets put into it, maybe these days we can work it out.
Did anybody of all these people wich tell these props are stupid ever try to print them the right way, why for example you tell they are bullshit no thrust and all this but if you have seen the Video from Quadmover for example you hear they are more quiet and you see they have tons of power.
tbf to MIT students, we all know we're stupider than them. That's why MIT and it isn't boosted audio, it's reduced quality on the Q&A part. Dr. Quads is a coach for the try-hards team attempting to create discourse among a LOT of people not just his targeted demographic. it is in fact the Dr who thinks we're all stupid.
How many hits did you take on the pipe before formulating these sentences?
@@33rdframe fewer than you with some satirically bad grammars to troll you with. *slow clap*
@@rogueFactor dude you nailed the cheezy 90s villain to perfection
@@33rdframe stop putting my age on blast!
Ok
What happen if it was made to 4 loop? Or 5 loop?
It would be so heavy
2:30 THAT PART! lol yes! Everyone is acting like this isnt just a *boat prop with a 5-10% angle change*
My own experimentation led me to believe that ducts are what quiet propellers the most. A good set of ducts with the proper-sized props runs much quieter than shrouded props and much much quieter than open props.
I have seen a video on TH-cam from the shorts section that showed these compared to normal. The sound was pretty much the same.
Hooray for affirmative action!
I'm not interested in whether they are quieter, more efficient or give more power. I think they look funny and that's why I want some
Fair point
That's also why you love mirrors
:p
The problem is they don't work. I've never watched this youtuber before, but was recommended this because I watch videos about FPV drones and Major Hardware (PC) Fan Showdown. I've seen at least 6 different people try around ~10 designs and none of them have gotten even close to replicating these results. Many of the videos also 3D printed regular props as a "control" to show that 3D printing doesn't have a dramatic effect on the final results.
Either there's some secret ingredient that MIT is hiding, or it is all bull.
Only reason I give MIT even a .0001% chance of being right in this case, is because of the Sharrow (which predates the MIT patent by 1 year). But water != air.
@@davidcheek8892 And especially nowadays it's quite difficult, because everything is already optimized to the maximum and it takes a long time to optimize it a little further, it's just not that easy. maybe in 10 years they will have something revolutionary... or not ¯\_(ツ)_/¯ But I don't know how long they'll be working on it, but that people quickly do the same thing and it don't work directly shouldn't surprise any one. The only one I've seen that has ok results is quadmovr
@@davidcheek8892 Exactly
And in water they work mainly cause cavitation is a real problem that can destroy the propeller quite easily, and avoiding it, which similar design manage to do, is important
But cavitation can only occur in liquids.
In water, when the pressure at the edges or tips of the rotating blades falls below the vapor pressure of the liquid due to the speed of rotation creating a partial vacuum in its path, bubbles are formed that contain water vapor. These bubbles collapse immediately, giving rise to shock waves, which can be as damaging as the impact of a bullet. See the mantis shrimp, for example.
The only effect similar (but still very different) in air would be if the tips of the blades crossed the sound barrier and create shock waves doing so... which in a drone doesn't happen. Drone blades are noisy due mainly to turbulence.
In modern blades noise has been greatly reduced, compared with the first generation, by a combination of blade profiles, rotor geometry and lower speeds (higher surface) propellers... less so in sporty drones at full throtle, which require inherently high speeds in their propellers...much more than the noise reduction the toroidal scam claims in its dubious paper
This is a lot of anger for something new in the industry. Even if they didn't provide any data, the idea is out there and i expect in a next month or so a lot of TH-camrs will do the testing and provide the data. And most current designs made by youtubers are such basic designs, similar to making 45 degree flat propeller blade. When the chords are tuned, and variable chords along the length, with changing pitch are made, there is no reason triloop design should be worse than 6 blade prop.
Keep in mind that MIT didn't even generate the hype, people liked the idea, and started making their own props, mostly 3d printed, not giving a cent to MIT team.
Saying that MIT doesn’t have data is like saying that politicians can’t talk!
You have listed more information than MIT did... jussayin
Bizarre amount of anti science in this video. I acopmpletely agree with you that nobody have the real model, i saw no simualtion on youtube and people as making it from a picture! To optmize this shape would take more than a picture and good will.
This youtuber used an improved version that uses a airfoil like model that shows excelent performance! th-cam.com/video/UNL8KXdAggc/w-d-xo.html
The "anger" isn't for anything "new in the industry", is for shoddy marketing bullshit disguised as serious science from a prestigious place that in any way should participate in something like that, as the vid devastatingly argues.
If you can't see the difference... well, that's the current problem. It's the postmodern XXI century paradigm about all opinions counting and everything, including physics, being about consensus and diversity. Puaj!
Dude. For real. What a weird take to get angry about. Lets just break it down, hes mad that college kids invented something, then showed us. Then because we live in the fucking future, we can quickly design and manufacture these on our glorified microwaves 12 minutes after learning about them. Of course theres no data released, its generally not the norm for specifics to be released to the public so we can all make our own right after something is invented. This is actually kind of gross.
The explanation the MIT guy gives on why it would make less noise is messed up and it clearly comes from somebody with no aeroacoustics background. At these Mach numbers, low subsonic, most of the noise is actually generated by the unsteady-loading dipolar tonal sources emitted at the blade passing frequency and harmonics (btw, this is how you can actually infer the rpm from their spectra on the "paper" they released). The noise reduction happens at these peaks because 1. you likely diminish the tip-on-tip aerodynamic interaction that takes place among the rotors and 2. because with swept blades you have a lower velocity component at the place where they are rotating the quicker, having maximum loads closer to the hub. And as the dipolar sound goes with Mach^6, you have an important reduction in the frequency peaks that make up the characteristic buzzing sound we hear. What the MIT guy refers to when talking about turbulence reduction is mostly related to broadband noise reduction (like trailing-edge noise, etc.), which is less problematic for these machines, and to the slipstream circulation reduction, which is linked to the tip-on-tip interaction above. Of course, reducing the velocity at the blade tip with a sweep angle can reduce quite a lot of the load and so the propeller's aerodynamic performance. I agree this sounds fishy. Yet, I would like to run an actual CFD simulation on this to see what happens. And I will probably do it. Thanks, Dr Quads for your work, the video was needed.
It’s Massachusetts, that should be enough of an explanation for the lack of data and arrogance.
Imagine if you could make drones louder to detect so you can react to them...
In the battle field?
I agree with most of what you said, but also thought some was a little over the top. One possible proof you of fraud you didn't mention is that companies like "Master Air Screw", who specialize in hobby props for drones etc., surely had heard of the water application and would have invested some resources into checking this idea out. And since we see nothing from them it's likely they found it a dead end. Still fun to print and play with for the hobbyists.
Yea since the “hobby prop company” didn’t find a way to innovate, certainly the institution that has played a key role in the development of modern technology and science since 1861 surely couldn’t! 🤦♂️🤦♂️🤦♂️
@@Delouser69 This reply baffles me. I was mostly agreeing with the video. I said some of it was a little over the top though. That was my way of saying I do think there's merit in looking into this and I thought some of Dr Quads comments were a little harsh. Working for a hobby prop company doesn't mean you don't know your stuff. There is a good chance designers there know more than some student trying to write a paper or even the professors for that matter. Why is this a highlighted reply.. That is so weird.
I'm going to send Dr. Quads a donation, as soon as there is a little more money in my account!
A group of people at MIT incorrectly claimed they built the first ion propelled aircraft of any kind with onboard power! There are nearly 50 public videos of my Ion Propelled Vehicles online, that are patented specifically for having onboard power supplies and lifting them against Earth's gravity as well as for the advancements needed to do it vertically. The crafts have been demonstrated with onboard power since 2006 and patented for it since 2014. MIT has tended to use the word "plane" more recently but is still being wrongly claimed to be first. My VTOL ion thruster can fly on one side as a plane with aerodynamic lift as well, even though the point is getting an ion propelled aircraft to lift an onboard power supply. The force of ion thrust tended to be quite low, so getting onboard power was a challenge. The efficiency and thrust to weight of the more recent MIT bungy launched version is nowhere near the level of the patented version.
This is just heartbreaking. And this is exactly what I am talking about. Instead of funding going to the people society actually WANT it to go to (i.e. the ACTUAL creative minds behind ion propulsion) it goes to some rich "bro science" kids who get it simply because they lack morals and integrity. So basically MIT is rewarding a lack of character and punishing creative ingenuity.
If people think this isn't there problem then they need to wake up
Luv you too Dr. Quads! It's sad, but there are 95,000 views over the past 6 months on your channel and zero thumbs up or other responses to my hearted comment. Something is definitely fishy there.
Thanks again!
The truest statement on youtube is that MIT thinks I am stupid.
OK, Sharrrow makes a toroidal boat prop. If you look at what is aurguably the most money spent on noise reduction of a water propeller it would be on a submarine. None of them are toroidal. They all are tip forwards curved blade, remarkably similar to a noctua 12 computer fan. The tip forwards feature is also found on condenser fans in the hvac field. If toroidal was the quietest you would see it on submarines where quiet is a life or death scenario.
this is the equivalent of "the proof is in the pudding"
No one claimed that it was the quietest propeller design. It's supposed to be more efficient with reduced noise being a benefit. I guess you're not an engineer or scientist.
@@Rampart.X I guess you aren't either. MIT have made bold claims without providing sufficient evidence. A scientist's default position should be scepticism until the evidence is provided.
@@malcolm_in_the_middle you're clearly confused. They don't need to provide evidence to unpaying, uneducated dolts.
@@Rampart.X yeah, not like i designed my own drones from scratch and perfect designed being copied by every manufacture now....
I didnt even see the MIT video before but I've been being slammed with Toroidal Prop videos I might jump in on the snakeoil and make one thats purposfully louder :)
I support this 🤣
The paper has pressure wave vs frequency. You can convert frequency to radians to get RPM, or am i missing something here? I do agree its fishy they don’t want to share actual sound but maybe big brother advised against it.
Maybe
"Never ascribe to evil what is adequately explained by stupidity." --Hanlon's razor