Toroidal propeller vs 3D printed EDF

People turn everything into a toroidal propeller these days but how good and quiet is a 3D-printed toroidal EDF?

Parts:

[hlavaatch]

The point of toroidal propeller is to decrease/spread the harmful vortices that form at the blade tips. Proper EDF has practically no space between the blade tips and the duct wall so vortices have nowhere to form. So toroidal ducted fan does not make sense

[grahamr]

Putting the test and results aside for a moment, what really delights me is seeing bright young people like this doing great things with their time and energy. Well done to Nikodem and everyone like him.

[easycheesy]

The demos, so far, are radially-fixed pitch. Since you're 3D printing each one, try experimenting with a radially-profiled pitch. You will achieve a better stall response and a wider, linear-region in the thrust-speed, response-curve... as you account for the changes in tangential prop speed, from hub to tip. A good starting point, is to assume decreasing-pitch as radius increases. This allows for the tangentially faster portion of each blade to create less turbulence and efficiently scoop air.

[ybanrab]

Interesting tests! One thing to also consider is that an EDF on a vehicle doesn’t normally see incoming air at 0mph. If it’s on an aircraft, it’ll be seeing air at flight speed, so the necessary pitch changes. Racing RC planes often have such aggressive pitch that the props sound terrible and don’t generate much thrust until they get into higher speed air

[coderentity]

The gap between the shroud and the propeller blade seems to be pretty big. That lowers the performance quite a bit as a vortex can form there. Other than that, good job!👍

[adamdelarozza]

The Best example i've seen of this new toroidal prop is underwater in propulsion mode. It moves almost twice as far with the same amount of power as the old school prop. It's a game changer and that's is something you'll believe soon.

[GoatZilla]

The best thing about toroidal props is that they're more structurally viable for 3d printing. That's really about it.

The 1 most interesting prop would have beeen... a 2-bladed toroidal prop.

You probably could have printed the props in ABS and then easily acetone smoothed them.

All your results need to be correlated with power.

[Calicarver]

I think the toroidal shapes you generated were suboptimal and would need further tuning. Better shapes are likely more soft organic shapes. The key benefit of these toroidal propellers as far as I have seen is when they operate at low to medium thrust and the efficiency drops off compared to standar propellers towards the high end of thrust. I am not at all surprised of these results. Neat to see non the less

[towitowi]

Cześć Nikodem, coraz ciekawsze a zarazem bardzo profesjonalne tematy poruszasz, tak trzymaj !

[lj]

I loved how you said "propeller" Thanks for the video. Keep it up!

[PaulDominguez]

I'm a big fan of this video 😂. Looking forward to seeing more

[Poult]

That's one hell of a pitch you've got there. It's mainly rotating air rather than pushing it. I'd guarantee the thrust would greatly increase with a shallower pitch.

[handy-capoutdoors]

Sir, you are designing stuff and making it at home and doing as close to scientific tests that you can. With the tools you have available on a home budget.

This was an awesome video. And you were able to not only display differences between your test samples but were able to highlight the more minute differences.
I'd like to see more of your videos.

And as a thought on the results and figuring out how to make an improvement. My personal opinion is to start looking at the propeller basics. Surface area and pitch. Followed by weight. The goal to take a commercially available EDF turbine blade, figure out the surface area and pitch to get a baseline volume per revolution of the prop. Then design a terroidal prop with the exact same volume per revolution. And make it lighter than the commercially avaliable prop.
Volume per revolution gives you a baseline number that also gives you baseline drag that the electric motor is put under. If rotating mass is identical and volume per revolution is identical then your electric motor efficiency should be close to identical. As in amp draw and rpm should be identical.

Eliminating the variables in this way should allow you to get better data on thrust and decibel levels when comparing the 2.
I use to build and fly r/c foam board construction aircraft and indoor gymnasium flyers. The electronics were the hardest part to get an efficient and light setup. And then quadcoptors showed up and all the skill in getting something tiny to fly and fly it well turned into who could afford the newest and better quad. Then the government crackdowns on the hobby happened and I didn't pick up a remote until recently.

[HappyMathDad]

I really like your videos. You already got really good advice. I look forward to the next video. Good luck!!!

[jamesbruce]

Did you calculate efficiency as grams thrust per Watt? That would be more interesting to me that just pure thrust.

[robinconnelly]

That was really interesting. Now I know that if i want want to reduce noise, toroidal is the way to go

[lio]

For context 6dB is double the power. 10dB sounds twice as loud

[LirE]

Great video as always - but make sure you explain what initialisms/acronyms stand for. I have no idea what EDF is and it is hard to even understand what your video is about without you providing that info.

[samsater]

I appreciate your efforts.... Great results ❤

[MarinusMakesStuff]

I actually believe these are not toroidal props as a toroidal prop has a curved edge along the outside instead of just being slanted sections of multiple tubes arranged around a center point.