Cycloidal marine propellers: Efficient thrust in any direction

https://newatlas.com/marine/abb-dynafin-marine-propulsion/

by Zobat • 2 years ago

100 45 2 years ago

newatlas.com

kayodelycaon2• 2 years ago

This isn't exactly a new concept: https://en.wikipedia.org/wiki/Voith_Schneider_Propeller

Tugboats use them.

Cieric• 2 years ago

That appears to have already been mentioned in the article itself. Reading over it it seems that the improvement here is fully independent control of all the blades. From what I can see in diagrams of the Voith Schneider Propeller it seems to be a single linkage to all the blades that cause them to all be at the same angle depending on their current position in the rotation.

If I'm getting this all wrong please someone correct me, I am interested in learning what the differences are.

dylan604• 2 years ago

That appears to have already been mentioned in the article itself.

I like how you let it go that it was the opening sentence.

all2• 2 years ago

The linkage system in helicopters was called a "swash plate", a rather ingenious method of controlling pitch of rotating elements.

agos• 2 years ago

individual blade control seems like a pretty big difference

wtallis• 2 years ago

It's a big difference in implementation, but I'm not seeing where they state whether it achieves any significant improvement in performance over existing cyclorotor designs like Voith Schneider. I think when they compare against "conventional shaftline configurations" they are talking about ordinary screw props.

supportengineer• 2 years ago

They had these for radio-controlled boats in the early 1990's.

pixelesque2• 2 years ago

And many smaller ferries.

godelski3• 2 years ago

If you simplify anything enough it isn't new.

If we required everything to be done in leaps and bounds, we'd never get anything done. Better to re-frame this as "looks to be an improvement on Voith Schneider Propellers". We can recognize the history while recognizing improvements. Progress is made by continual small steps, not giant leaps. If you see giant leaps, it is generally because you just aren't familiar with the topic enough (they do happen, but they are quite rare). Over trivializing improvements and dismissing them because they are abstractly similar only stops the world from moving forward. To reference a clique (something everyone can recite but something nobody knows): "the devil is in the details."

If you read the article, they say that the propeller decrease energy consumption by 22% from conventional shaftline (the video says "up to 25%" though...), that seems like a pretty big win to me. And seems like something that you shouldn't so quickly dismiss.

This kind of issue seems prominent around here and among engineers. Just remember how your work's merit relies so much on the details. What makes you think that this is any different for others? Why conclude that just because you understand something at an abstract level that you understand it at a nuanced level?

Edit: don't use this comment as a reason to downvote them. If you actually like this message upvote them to make this more visible because you're probably frustrated with this issue too.

tda• 2 years ago

The article is to light on details to claim anything radical. The operating principal is the exact same principal as a Voith Schneider Propeller, but then with more actuators and less linkages. That too me could just as well be a cost saving thing. Especially as they compare it too "conventional shaftline", and not to a Voith Schneider (I think). Also Voith Schneider's are already available in a in an electric version (eVSP) for diesel-electric drives.

Perhaps this new Dynafin is much more efficient than an eVSP because better tuned individual control optimised by AI and industry 4.0 allows for much better control. But it is equally possible that there is exactly zero advantage to this system and all we read is marketing BS. Hefty improvement claims without details are usually BS in my experience

michaelcampbell• 2 years ago

This intrigues me although I'm convinced almost anything that touches water is more expensive than I'm willing to pay for a hobby/pastime, but I went and looked up to see how these work. Neat.

https://www.youtube.com/watch?v=Ub563Yc3xls

lawlessone• 2 years ago

looks like bundles of kitchen knives.

nickpinkston• 2 years ago

That was my thought too, shoved through slots in a marble countertop.

interstice2• 2 years ago

As if I wasn’t already reasonably scared of swimming near boats

apendleton• 2 years ago

If it's any consolation, I'm pretty sure the leading edge is the blunt one, not the sharp one.

klyrs• 2 years ago

I'm not a swimmer but that sounds like a pretty reasonable fear. A propeller of any sort will mess you up pretty bad. And if I understand correctly, the larger vessel gets the right of way so if you aren't in a vessel you just go smoosh.

gravescale2• 2 years ago

Each blade is individually controlled by an electric motor, a frequency converter (to control torque and rpm) and control logic"

I know it's far from the only, or even most critical, embedded system on a ship, but being stuck at sea because your propellor CPU crashed, bricked during an OTA update or got taken over by a crypto miner does feel like it lies squarely on the current trajectory of reality.

TeMPOraL2• 2 years ago

Reminds me of a seaQuest episode, in which they had to hit a black market for an A/C chip for their sub; the captain was complaining that they can't get it through procurement, but were he to ask for a nuclear warhead, he'd have the weapon helicoptered in a hour later.

gravescale2• 2 years ago

I don't think ABB would sell you just the chip, you just know that's going to be a sealed module that costs POA dollars per unit!

ermir• 2 years ago

So this is like a helicopter propeller system, but the individual blades point upwards.

t0mas88• 2 years ago

Jup, except that a helicopter system does not use independent control. The blade angle is controlled mechanically, each next blade will at the same position have the same angle. This new thing seems like it has independent control of each blade. But I'm not sure what they can do with that that wasn't possibe with a helicopter-like setup.

I think it's unlikely you'll see a helicopter with this tech soon. This runs at 40 rpm. A helicopter main rotor is more like 400 rpm. And getting a blade "misaligned" at speed in a helicopter would immediately tear the whole thing apart.

hasoleju• 2 years ago

During the last centuries there was a technological shift in cargo ship drives roughly every 100 years. From sailing to steam boat over combustion engines to these drives?

psunavy032• 2 years ago

The basic principle has been around for decades.

sp332• 2 years ago

85% efficiency

Hm, is that a lot?

independent testing of a passenger vessel fitted with different propulsion systems found that the ABB Dynafin solution managed energy savings of 22% compared to conventional shaftline configurations.

Oh. That's a lot!

pixelesque2• 2 years ago

That's compared to propeller shafts I think (and powered by what? Diesel, Gas turbine?).

Voith Schneider systems are generally used on tugs and smaller ferries due to the manueverbility control they provide, it's not clear how energy efficient Voith Schneider systems are to shaftline systems.

Eddy_Viscosity2• 2 years ago

Its efficient at low speeds which is why it can be used on tugs. You want see these on a speed boat.

ilove_banh_mi• 2 years ago

In case you wonder how landlocked Switzerland would be so involved in such marine work, ABB is a Swedish-Swiss corporation and the pictures were clearly taken in the Baltic Sea (in the Gulf of Bothnia or Gulf of Finland).

psunavy032• 2 years ago

Still not unusual. MSC is one of the largest ocean shippers and based in Switzerland.

perlgeek• 2 years ago

I really hope this works out.

The cynic in me immediately says "so many moving parts, maintenance will be quite a problem", but I don't really have the expertise to make that a argument against the success of this concept.

n3storm• 2 years ago

I am more worried about there is no video of a ship moving on three main website and youtube videos. One is 12 min. Only men talking, 3d animation and lots of waves. Did not search further though.

Should this be called foamware?

TaylorAlexander2• 2 years ago

Wikipedia says this type of propeller is widely used on tugs, so I guess the ABB product is either just their own version of this tech (maybe a patent expired) or they have evolved it somehow, maybe to increase efficiency depending on how you interpret the article.

https://en.wikipedia.org/wiki/Voith_Schneider_Propeller

Here is a video of a tug boat using this technology, sadly only showing the boat moving but no close up of the propeller.

https://www.youtube.com/watch?v=u6uNECa_X8Q

Tuna-Fish• 2 years ago

It's not quite the same.

In a Voith Schneider propeller, there is one power input (as in a rotating shaft) plus a second shaft input that gives the desired thrust direction, and a complex gearbox that drives all the blades and the collective. These are in wide use in tugboats and the like, desired for their ability to output thrust in any direction at a moment's notice. However, their disadvantages are that they are less efficient than traditional propellers, and they don't scale up to high revs or high power output all that well, because of the gearing and the mechanical losses involved.

In this design, there is one large electric motor that drives the collective, and an individual electric motor at the base of every blade. The claim is that this gets you the maneuvering advantages of a V-S, while not suffering from the same disadvantages, and because of better control over the blades is not just more efficient than a V-S prop, but more efficient than traditional screws. And in theory it should scale as big as you want it, which would genuinely make it a significant advance that would see fairly rapid adoption.

That's if it actually works in practice, the only prototypes so far are very small and you don't really know if something scales until you actually scale it.

godelski3• 2 years ago

I have a response to what was the original top comment but now got displaced[0].

In short:

1) If you trivialize any technology nothing is new. Advances happen (mostly) by small steps, not leaps and bounds. According to the article it is more efficient. Seems like a win. Even if it isn't huge or crazy different. Is the lack of novelty because of: their tech? Our understanding of the tech? Something else? Who cares? If it is different it is different.

2) So what if it isn't (very) new? According to that wiki article that engine is made by one group. So even if its novelty is simply different enough to bypass a patent or in house knowledge, so what? More competition is good. What's the point here? We love monopolies? Only one company can make one type of thing? Type being at the abstract level, not detailed?

I'm not sure how either of these is helpful. Maybe you're saying something else, but it isn't clear to me.

[0] https://news.ycombinator.com/item?id=40044358

ChrisMarshallNY• 2 years ago

Looks like a Ginsu Propeller™. Slices, dices, etc...

In all seriousness, it would be great if it worked out, but we are constantly seeing marine tech being messed up by the marine environment.

There's a reason that every damn thing that has "Marine" in its title, costs ten times as much.

It really, really sucks to be stuck out in the middle of the ocean, because your shaft rusted.

geor9e• 2 years ago

I'm so confused how this works, but based on this animation I found, it seems like it just shoves the water sideways in the direction of thrust, then turns so it's cutting though the water in the opposite direction https://www.youtube.com/watch?v=Ub563Yc3xls

Cycloidal marine propellers: Efficient thrust in any direction

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