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The MIT Lincoln Laboratory is developing near-silent toroidal propellers!

published: 02/02/23, 19:12
by Christophe
If the thrust and propulsive yields are the same, it's amazing! : Shock: : Shock: : Shock:



Screenshot 2023-02-02 at 19-09-58 TVO_Technology_Highlight_41_Toroidal_Propeller.pdf.png
Screenshot 2023-02-02 at 19-09-58 TVO_Technology_Highlight_41_Toroidal_Propeller.pdf.png (437.3 KiB) Accessed 3535 times


Screenshot 2023-02-02 at 19-09-48 TVO_Technology_Highlight_41_Toroidal_Propeller.pdf.png
Screenshot 2023-02-02 at 19-09-48 TVO_Technology_Highlight_41_Toroidal_Propeller.pdf.png (118.23 KiB) Accessed 3535 times




https://www.ll.mit.edu/sites/default/fi ... peller.pdf

https://superinnovators.com/2023/02/nov ... ess-noise/

Future Dragonfly propellers? 8) 8) 8)

ps: almost silent... according to the videos... I didn't find any indication of dB at equivalent thrust... :|

MIT report (summary):
TVO_Technology_Highlight_41_Toroidal_Propeller.pdf
(1.45 million) Downloaded times 479

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 02/02/23, 19:17
by Christophe
It also works in hydraulics (the sound of the propeller travels that much in the air??)



https://newatlas.com/aircraft/toroidal- ... ropellers/

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 03/02/23, 20:45
by Petrus
We won't even hear the killer drones coming to eliminate us, great!

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 07/02/23, 18:03
by Christophe
After :



(all is not true)

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 13/02/23, 18:37
by Christophe
The comparative yield curve...what explains the fall and rise in yield? Cavitation? : Shock:

toroidal marine propeller yield.jpg
marine propeller toroidal yield.jpg (85.23 Kio) Consulted 3051 times

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 03/03/23, 18:24
by Christophe
I'm going to test 3D printed toroidal propellers on one of my aero test benches...

Here are some models:

6 blades: https://grabcad.com/library/toroidal-pr ... -6blades-1
4 blades: https://grabcad.com/library/toroidal-pr ... 4-blades-1
3 blades: https://grabcad.com/library/toroidal-propeller-2
2 blades: https://grabcad.com/library/toroidal-pr ... 2-blades-1

Well, this will take a little time... To be continued!

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 03/03/23, 18:39
by Remundo
the idea seems very interesting to me.

It is the same approach as the winglets in aviation.

We prevent the wing from "terminating" and in doing so, we reduce the wingtip vortices.

I can believe it decreases noise, and maybe even increases performance.

So maybe there are other downsides, does it increase the drag of the spinning blades?

Apparently the inventors are confident and announce record yields.

To be continued.

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 03/03/23, 18:50
by Christophe
Well, the best thing is to check for yourself and I have all the tools at hand: 3D models, 3D printers and aeronautical test bench! So why deprive yourself?

I think the comparative efficiency is better in hydrodynamics than in aerodynamics...and I don't really believe in Santa Claus: submarine manufacturers have been working on (the sound level of) their propellers with billions of budgets for 80 years ...and they would never have discovered this hydrodynamic "trick"?

Yeah...to be continued!

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 03/03/23, 18:57
by Macro
Have you seen a military submarine propeller in use?

I think it's a part of their "anatomy" that we try very hard to keep secret

Re: MIT Lincoln Laboratory develops near-silent toroidal propellers!

published: 03/03/23, 19:01
by Christophe
Well shit, I'm stupid !!

Come to think of it, I already printed one a toroidal helix for testing in my stream 2 years ago...I had found this model on https://www.thingiverse.com/ well before MIT communicated on it suddenly!

I just found the 3D print in my "archives", the toroidal is 225 mm and the classic 200 mm.

thoroidale_hydro.jpg
thoroidale_hydro.jpg (122.36 KiB) Viewed 2760 times


Well comparatively in the stream...despite its 25 mm more on the diameter...the toroidal, this is big shit! : Mrgreen:

The torque was much lower than the other for the same water speed!

So I'm less motivated to do aero tests... : Shock: