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Voith Schneider Propeller

en.wikipedia.org

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Re: Voith Schneider Propeller

#11

Post by brk »

javiramos wrote: post #4

The coolest recent development in marine propellers is toroidal propellers which are now commercially available and seem to perform significantly better than standard propellers: https://www.sharrowmarine.com/

For the most part the Sharrow props have not proven to be much of an improvement, particularly for the high price.

The tests that have shown "significant" improvements have frequently compared the Sharrow to a sub-optimal prop. Feedback from many actual users is that the gains are moderate over a narrow RPM range.

Re: Voith Schneider Propeller

#12

Post by brk »

xpe wrote: post #9

From a resilience POV, my guess would be that failure of any one blade would botch the system overall. Maybe that is why many diagrams show them installed in pairs. (I would guess each operates in a different direction for angular momentum reasons.) I have no idea about overall reliability.

For marine applications dual drives are common as it enables better rotational control for maneuvering. The redundancy aspect is also a factor, but moreso for applications where you are going to be far from shore. For tugboat and ferry type applications, where these drives are most common, that is less of a concern.

Re: Voith Schneider Propeller

#13

Post by closewith »

brk wrote: post #11
javiramos wrote: post #4

The coolest recent development in marine propellers is toroidal propellers which are now commercially available and seem to perform significantly better than standard propellers: https://www.sharrowmarine.com/

For the most part the Sharrow props have not proven to be much of an improvement, particularly for the high price. The tests that have shown "significant" improvements have frequently compared the Sharrow to a sub-optimal prop. Feedback from many actual users is that the gains are moderate over a narrow RPM range.

And much harder to repair.

Re: Voith Schneider Propeller

#14

Post by HPsquared »

javiramos wrote: post #4

The coolest recent development in marine propellers is toroidal propellers which are now commercially available and seem to perform significantly better than standard propellers: https://www.sharrowmarine.com/

That's pretty cool, but I wonder if they can get stuff tangled in there.

Re: Voith Schneider Propeller

#16

Post by adolph »

yccs27 wrote: post #2

This reads a lot like an advertisement. The linked page [[Cyclorotor]] is more neutral and has more information on the design and applications outside of marine vessels: https://en.wikipedia.org/wiki/Cyclorotor

This is conceptually significant because the article links the mechanisms used in watercraft and aircraft.

Re: Voith Schneider Propeller

#17

Post by HoldOnAMinute »

LoganDark wrote: post #6
javiramos wrote: post #4

The coolest recent development in marine propellers is toroidal propellers which are now commercially available and seem to perform significantly better than standard propellers: https://www.sharrowmarine.com/

That website seems to no useful information; only marketing speak about how great it is... Do you know of a good source on how toroidal propellers work and the engineering behind them?

I didn't even see a picture of the propeller, if there was one. There was a giant, white, blank space.

Re: Voith Schneider Propeller

#18

Post by LoganDark »

HoldOnAMinute wrote: post #17
LoganDark wrote: post #6

Earlier quoted context omitted.

That website seems to no useful information; only marketing speak about how great it is... Do you know of a good source on how toroidal propellers work and the engineering behind them?

I didn't even see a picture of the propeller, if there was one. There was a giant, white, blank space.

That space is blank for me too.

This page seems to have one halfway-functional photo for me: https://www.sharrowmarine.com/store/p/sharrow-by-veem-ds9sw

This URL may work: https://images.squarespace-cdn.com/content/v1/560055b1e4b017...

Re: Voith Schneider Propeller

#19

Post by AftHurrahWinch »

LysPJ wrote: post #7
LoganDark wrote: post #6

Earlier quoted context omitted.

That website seems to no useful information; only marketing speak about how great it is... Do you know of a good source on how toroidal propellers work and the engineering behind them?

Here you are: https://en.wikipedia.org/wiki/Toroidal_propeller

Really enjoyed this:

> In the centuries after Archimedes invented the Archimedes' screw, developments of propeller design led to the torus marine propeller... it was invented in the early 1890s

"the centuries" indeed. :)

Re: Voith Schneider Propeller

#20

Post by ted_dunning »

oliwary wrote: post #15

Cool, similar to helicopters which can also control direction indepentendent of thrust, which leads to RC helicopters being able to pull of crazy, physics-defying moves like here: https://www.youtube.com/watch?v=QSiwyoQldfo

That is bizarre and amazing. I have never seen any kind of aircraft that resembled a dragonfly as much as that.

The maneuvers are so extreme and come so fast that I would not have been able to say for certain that this wasn't just a very nasty crash in progress. But they were, in fact, completely controlled and intentional.

Incredible.

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