I Turned MIT Award Winning Toroidal Propeller Into A PC Fan | Fan Showdown S5 Special 

ayyy sup

Yes, definetly some vibration sounds occuring due to inbalance

Could some of it also be due to the fact that these are ducted? I was under the impression that ducted fans were more efficient mostly due to the reduction of those tip vortices

let the man cook

Came to the comments to say this, noticed real engineering already chimed in. 👌 Also noticed he acknowledges the same things at the end of the video.

Yes, two years ago. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-vsqi6SP0NhE.html

This 🔝

He did a pretty long time ago I think.

There's an episode where he did that.

As David Cheek already stated, he's done this before (I've already replied to another comment in another video actually) - he did it before the fan showdown became a thing: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-vsqi6SP0NhE.html

I'm blown away nobody else saw this. The toroidal design is basically half-way between an open and a ducted fan. You're spinning 3 short ducts. So putting the three inside a larger duct is not only redundant, I suspect it detracts from the efficiency.

@@AlexKarasev You might be right about that. That's why I suggested testing both inside and outside of a duct. The differences could be very interesting.

Exactly the point I just made with my post before reading this, LOL

LOL was about to type about the ducted configuration causes performance difference and the build purposes, glad I looked at the comment section before I went brrrrrrr.

Yep. I came to this video because of having looked at some vids about toroidal props. I like this guys style, he seems very straightforward and good testing. And super talented making it from a picture. But all that is sort of moot because the point of a toroid is to create something like what a duct does. The duct is already breaking up that turbulence at the end point of the blade. As Laughing one points out the comparison to do would be a ductless version. But in that case it's no longer a computer fan.

wow. that's a hell of an efficient prop then. I was wondering if the prop helped reduce fuel consumption as well.

So buying a 5k prop will save you 10k in fuel if you go out on the boat enough times in one year? That is quite good, and if everyone did the same I wonder how fuel prices and supply would be effected?

@@Koronosavilon unfortunately it will not be affected. Boats make up a minority of fuel consumption... now, if we are talking cargo ships, we could perhaps improve cargo ship fuel economy. That would mean lower cost of imports.

@@NoobNoobNews Surely cargo ships already run the most fuel efficient props known to humanity, the engineering into making those things run cheaper is incredible!

@@NoobNoobNews I hope that you x thought that those cargo ship propeller is just as simple cheap propeller 😂…it’s more complex and far more advance with multifeatures

Came here to say this ^ , thank you.

This is the key part. Inside the fan shroud this is really only a 3 blade fan with cool toroidal shape blades.

And possibly for a very different RPM-Range at comparable diameter.

@@miagi1337 everything here is what is stated on the video, did any of you guys watch it in full before commenting? xdxd

exactly, probably lots of shear from the outside edge of the toroidal to the wall, probably over double on the exterior since its roughly a 2-sided surface ring rotating on 1 surface of a ring.

With refinement this design could well double the operating speed and cfm of fans while keeping the noise at a more acceptable level.

Yep can't wait for a company to implement this design

Matching the noise level with lower hydrostatic pressure and airflow is a phyrric victory though... because to match the air flow you would need to double the speed, meaning a huge increase in volume. You could match the volume with any blades if you turn down the rpm enough. It's definitely a cool result and first step, though.

5dB of difference is quite a lot, and not “matched noise levels” lol

@@DashzRight Yes, but keep in mind this is a first attempt home made fan vs the result of hundreads of tested desingns. Now it would be insteresting to see noctua pick this design up to see a real comparison.

I see whatcha did there. Nice. Don't be a quiet fan, though. ;-)

Nailed it, its out of the park.. Def fan

Well, I'm a HUGE fan after watching this, and it's my first time!!!

fr

me with a fan:

Yeah lol I imagine that would make a difference

Opportunity for 3d metal printing then

I mean you could use a converging and diverging duct setup to minimize the static pressure the fan has to deal with, but that'd going to some great lengths just to use a fan not designed for the application. I have thought of doing a small version using 3 120 fans on a 3x140 radiator but again that's going to kind of a silly length for probably minimal gain at best.

@@andyparker8631 Pretty sure that casting is wayyyy faster.

@@andyparker8631 Cast and cleaning is much cheaper/faster for production and they'll be able to drop that machine time down significantly while retaining a lot of quality of the billet part at a fraction of the cost. 3D printing has it's place but is still way out there when it comes to mass production.

Yeah, acts more like a ducted fan rather than an open air prop

it would be interesting to make it spin at 10k rpm.

I was about to leave this exact comment, also why modern jet airliners are much quieter than older prop aircraft!!

I was thinking this as well. Also the toroidal fan isn't designed with the housing "legs" in mind so the blade-pass-frequency could be quite bad.

I'd also say the MIT fan is probably also squishing air against the sides of the , shroud?

Yeah, if the shroud was removed, and the blade angles were optimised, the Toroidal propeller (while possibly still not beating the Noctua) would still be a decent, high performing and quiet option. I wonder how it'd go on a graphics card (or CPU) air cooler, where the fan wasn't covered by a shroud vs a dedicated aircooler with the standard fan style.

Yeah toroidal fan has no advantage inside a duct.

Not through a radiator or filter

@@VeritasEtAequitas as in static pressure vs airflow?

That's what I thought. Maybe a ducted fan already limits blade tip vortices.

Good argument, but is a caseless fan still a PC fan at that point?

@@EdwardChan.999 I think that's the point, that PC fans aren't the best application for toroidal propellers, nor were they designed to be. Every prop has an application.

^this^ The math behind fluid flow mechanics is fiendishly complex, and TINY adjustments have massive downstream impacts on efficiency and performance. I’d be curious to see a design that was fully optimized for the task and see how it performs.

@@munchkingod6 Yea, or at the very least smooth out the surface that's still jagged from the printing method...

yeah this is what I was thinking the entire time, the only thing this test showed was whether or not the design was viable for a fan at all not whether it can actually compete with standard bladed fans in PC cooling. a quieter drone propeller is useless if it can't keep the drone flying. granted that is the final conclusion he came to as well, so it'll be interesting to see a similar design with more stages of optimization and QC

@@munchkingod6 To be fair, he did mention that the results from MIT were based around much higher RPM.

That´s why I am witing ro a A.I. / chatGPT model / design!

The F-35 comes to mind here. It's apparently 20% louder than any of our other aircraft. It has a much deeper sound to it though, especially compared to the Harrier which it replaced. The harrier still sounds way louder and far more annoying to be around lol.

Yes yes drone test this!

The point is to reduce high frequencies that travel far. To test this the sound meter should be 10+ meters away from the fans in a stadium or other very large room.

do it!

You will see these types of propellers come out for purchase from high quality manufacturers in the next couple months.

and a set of a12x25 blades on the drone for the sound comparison lol

Ahahahah MIT inventing old german technology as per usuall XD Good one for spotting that out

Underrated comment.

Idk about other videos but the one I watched they did say that’s what inspired the build and designing of these blades so he never claimed to have invented the idea just did testing to improve it.

On the noise aspect, definitely. Was thinking this too, Noctua isn't comparable to a drone propeller if it's in it's frame. Well, not otherwise either (blade count and shape to start with), buy anyway; the frame will help with those tip vortexes.

@@Garbox80 ducted fans for drones and ducted propellers for boats exist too, so i wonder if the toroidal prop design has advantages against those beyond weighing lighter.

@@sepg5084 I mean I feel like weighing lighter is the name of the game lol.

It might have been because he mad a community post here? I saw a post on reddit about it in a sub frequented by the kind of folks who watch his channel, someone else probably saw the post and posted about the tech on reddit xD

Same! Immediately thought of MH when I saw that :D

But why? It's fun, but as he said a PC fan never spins that fast. And most importantly, the PC fan is shrouded, while a drone propeller is not.

Before I even read the article that I saw, I skimmed and saw pictures of boat props and my head immediately went to fan showdown lol then I read it and watched a clip of both a boat and a drone using variations of it... Pretty cool stuff. I always wished I could fly a drone near someone without them hearing

I was thinking the same thing. You just eyeball it, slap it in, without as much as treating it, much less, like, sanding it glossy, turn it on, and get a result with less high frequencies and almost the same level of noise. While Noctua are like the cutting edge engineers in the field. These blades probably went through hundreds of hours on the design boards and dozen of physical edits.

Some 600-grit sandpaper, maybe a coat of something just to stick in crevices, and a whirl at 'wheel-balancing', for instance.

No it wasn't close. Noise should be compared at same airflow and/or pressure - not RPM. Otherwise I can make a disk "fan" that's just a flat spinning round piece of plastic, and it'll be practically silent on its own but move ZERO air.

@@AlexKarasev great point

if the fans could go up about 1k rpms youd notice the benefits of the toroidal prop. it would out preform the standard fan.

2000 rpm might also be too low. Smaller fans use higher RPMs. Maybe try with a 40mm high flow fan? Because from my experience, small fans can be very noisy in the higher frequencies.

agree, I'd suggest printing the propeller on a resin/SLA printer instead

but even if it dropped the noise levels by 10%, it would put it right in line with the other fan. While it is cool to think that it is as quiet as a noctua which are notoriously quiet for pc air cooling, 2k rpm just isn't fast enough to see a huge change in db.

I think a better option, would just be to print a design similar to what's found on the noctua. So they both have the same disadvantages.

@@internetcancer1672 Good idea

anyone who sells a brown fan, clearly has their s#&t together.

I am a Noctua fan, and I can tell ya we ain't full of hot air! but quite the opposite we push cool air at components quietly and efficiently.

@@JustKanji haha noctua fan

@@JustKanji punny

@@JustKanji Im black and homosexual transgender muslim. It's very important.

Maybe you can do a demo of it and see if it would compete.

Might not have a printer

@@di_spencer7372 I have not been to a public library in the last 2 years that doesnt have one now, but then again I have only gone to 3 different ones & they were all within 1 hour of either Milwaukee or Chicago aka not extremely rural (one was legit in a small farming town though).

@@von... lmao this city to poor to let us have nice shit

I agree. An additional lever to pull: adding depth like the Sharrow water props would also increase the surface area and probably help channel the air and keep it moving towards the output.

That's my first thought as well. Increase the fan depth to allow for over lapping rings at higher density.

Essentially, the “peak” shape just becomes sharper but there is significant loss of air pressure due to the “openness” of the shape itself. High pressure usually = loud.

Also, with this Toroidal design, the self shroud of the propeller is interfering with the shroud of the assembly, causing noise and power losses.

You can hear the toroid rattling in the shroud also wich surely accounts for some of that volume

I noticed the number of blades also. One more thing to check is how much power is being used, check both with that toroid and one with more blades, with an AC current they will tend to spin at about the same speed.

I would suspect total surface area towards the air would be the dominant factor. The least Cd w/ the greatest surface area would win.

@MajorHardware Also, the 45° Angle of Attack is WAY too aggressive! It should be around 15° at the root and slowly decreasing towards the tip. Angling the propeller so much will cause it to stall, which will drastically reduce performance and increase drag (due to the massive amount of turbulence generated)

and the profile of the wings does as well change effect. I think that the lower frequencies might have come from vibrations due to unequal material thickness and/or excentricity

I have a few 1U servers with a bunch of 40mm high speed fans, and, let me tell you, they're loud as F (especially during reboot or CPU intensive operations)

@@davestorm6718 22000 RPM goes BRRRRRRRRRRR *crackling headphone noices* RRRRRRRR

I was thinking he needed to reprint this for a high speed delta fan and retest it

@@davestorm6718 I had a system in 1U, watercooled, and use radial fans in it. Now I got another one, and need to get some more big radial ones. Got a new gamign system in 2U and it is a lot quieter, I think if I had an easy way to mount the gpu and not needing a Protocase custom order or heavily modded case, I';d have done it in 1U again. You can help the noise if you really want to.

The MIT design you copied only had 3 blades. The toroidal version likely performs better than a conventional 3 blade fan. In order to perform as well as the Noctua design, you would need to make a toroidal shape with an equivalent number of blades.

Yes, since you know the speed it should work you can make it work perfectly for just that speed

Yeah, I think a lower angle of attack on the blades would be optimum...say 30°or less possibly

Reynolds number (ratio of intertial to viscous force) is length x velocity x density / viscosity. You won't get that to be the same. Specific speed (rotational velocity x flow**0.5 / (g x head height)**0.75) might be the same.

Exactly. I would love to see like overall stats from the various ones tested. So you could theoretically then combine the advantages of the various optimal fans. Though the official one seems to be highly optimized already, while all the others are barely test of concept stage. So any doing vaguely decent against it is a huge sign towards that design being easily better, in certain ways at least, after a few refinements. Then material testing and and refinement to fix any changes due to that and you have the best min/max'd fan ever.

might also be interesting to try it out with doubling the thoroidal blades, fusing one set into the other

Except we're missing the scale. If the noctua is top dog, how much worse is average dog and bottom dog, and how does the toroidoal compare to those respectively?

Not sure how well it competes, really. It's moving half the air and making a little more noise. Not to say it couldn't get better. But it's not like it was just barely worse than the Noctua.

@@BrettBreeden Keep in mind that airflow and static pressure are not the same thing. At half the static pressure, this unoptimized design isn't something you'd want to put against a radiator, but in the smoke test, it doesn't appear that its airflow is that far from the Noctua.

For our shop, I build a closet for our Clear View cyclone dust collector. It's built with two layers of 5/8 drywall and uses an exterior steel door with more 5/8 drywall on the back side of it. Then I built a set of baffles floor to ceiling and about 18 inches wide that just have a 3-inch wide opening that is alternated from left to right with each layer of baffling, which are 3.5 inches apart. It's quiet enough to have a conversation in the room while it runs. We have really high-end (I want to say 1 micron, but I would have to look to be sure) filters on the outlet and recirculate the air in the shop so we can easily maintain temperature and humidity. A better fan design is a great idea, but this was easily done at a low cost.

Dust collectors would use turbine/impeller type blades. The difference there would definately be interesting

@@ericapelz260 yes there are ways to work around the noise if people have the space. But there is a reason so many high end vacuums sell compared to shop vacs with a noise barrier, some people will pay for the convenience. That's one thing that bothers me about the festool groups. When a problem comes up their solution is always to buy more festool. Clear View is an expensive brand. If there was an option to buy a quieter unit with a 20% markup I believe it would be a popular choice.

Some nice outta the box thinking!

@@Otto-W I agree a quieter unit could draw a premium. We already had the Clearview, so this was a retrofit. It could also work with a shop vac if you had enough hose to reach things. There always is more than one solution to any challenge, and each will have it's place. (FWIW, we went with Clearview because we wanted to re-circulate the air but wanted to minimize the health hazards )

Problem is unducted PC fans don't work all that great to begin with! In PC space there have been some unducted fans, particularly the Arctic F Pro series, but they make up reduced performance by just being THICC, and also only partially. 40mm instead of the usual 25. They failed to make an impact and largely got themselves killed off. They do sound pretty nice and unobtrusive but they also didn't shift a lot of air. Though i think with this sort of blade construction it may be worth another shot?

My thoughts exactly. The whole idea is centered around silencing non-ducted propellers. So having them in a ducted PC-fan kind of defeats the point.

The comments under the first showdown that the Cheater competed in made me aware that fan ducts aren't as common in PC cases as they used to be, despite being so obviously useful in improving airflow. I wonder if it's because they get in the way of gamers' oh-so-important lightshow. 🙄

@@stevethepocket You're thinking of the wrong kind of duct; the fan frame fully envelops the fan blades and thus makes it a "ducted propeller"; as opposed to an "open propeller" like what the original paper is aiming for for its usecase. Ducted cooling assemblies, where you have a shaped pipe connecting some outside opening to a fan, have only ever really been a thing in mass-produced prebuilts, not in standard-parts custom-built PCs, because it turns out this is kinda impossible to standardise across so many possible part combinations. And with prebuilts leaning towards overpriced throttling garbage today, there really isn't much incentive to put thought into airflow engineering, just slap the cheapest thing on it that barely works, people who buy these things don't know any better anyway. I would actually welcome a step back from tempered glass sidewalls and back to polycarbonate ones. For one they're pretty robust and cheaper to replace; for other you can do things with the sides - drill vent holes and such. A large downdraft cooler, side vent for it, and some DIY ducting to help it draw the advantageous outside air could be a thing. You can have aesthetics (or "aesthetics") and functional design both. This is actually about what i've been doing but i've got that old Scythe Grand Kama Cross and just steel sides. Apropos functional design vs. aesthetics, what's up with enclosures that have so much glass even covering the front, they have no chance of supplying the requisite air?

​@@SianaGearz If you're saying that cases with built-in ducts aren't feasible because of the wide array of places the CPU could be positioned on the board, that may be true, but that's when you just go with what my last off-the-shelf PC did: having half the panel covered in holes and making the duct attach the heatsink instead. You'll want all those extra holes anyway so the graphics card (and any other components on the board that get hot; apparently even SSDs and RAM have heat sinks now) can get fresh air too. Actually, depending on your computing needs, that graphics card might have _more_ use for a ducted fan than the CPU would, and for that... yeah, I've never seen anyone do that and I have no idea how it would be done.

If we are talking about drone props, here is how bladenumbers affect things: Fewer blades = more speed (due to less drag), lower efficiency, more noise. Dual blades for highspeed builds, very loud, need beefy motors and high-C batteries. Quad blades have less endspeed, but more bite in corners, motors can be smaller and lighter. Tri-blades are a nice medium, both for racing and freestyle drones. I cant figure out why all the camera drones have mostly dual blades...

Apparently the tips make the most noise on a normal fan, and by merging the tips you remove the tips. No tips, less noise.

Probably work in a sci-fi setting

I think that'd be pretty much impossible to have the blade angles tip to work like a heli unfortunately 🫤

@@androiduberalles, yeah helicopters need collective pitch for attitude control

@@riongronberg1435 What if the whole thing could be flexed? I don't see how it would be possible but it's interesting to think about.

@@ddegn Maybe some pivot mechanism like this ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-55G-mwT9uCE.html

ha, spin off

That would be great!

Get. Out!

I agree, that's the first thing that struck me - ducting changes the circumstances of a relatively straight blade. Essentially the toroidal blade is a halfway house between an open-ended blade and a ducted blade

for the basic kits almost everyone can afford it. The question is desire and laziness

@@drozdoves Well I'm probably an ignorant in the subject then, what are your recommendations?

correctomundo - different profiles for different purposes

5:34 - incorrect test. He puts usual fan to the tube and increased its performance.

I would love to see a copy of the noctua fan on a drone! Especially given the pretty high volume of air it shifts, plus noctua's legendary low noise profile.

And use the drone blades for cooling the computer.