Cycloidal marine propellers: Efficient thrust in any direction
newatlas.com
newatlas.com
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.
Should this be called foamware?
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.
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.
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.
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.
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!
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.
Come to that, shallow water would be fun.
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.
Tugboats use them.
If I'm getting this all wrong please someone correct me, I am interested in learning what the differences are.
I like how you let it go that it was the opening sentence.
Traditional V-S loses a tonne of efficiency in the gearbox. It's less efficient than conventional shaftline. So if this is more efficient than the latter, it stands that it's moreso than the former. (Agree that I'd like more technical details.)
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.
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
Yeah I mean I'm not sure why this article was posted to HN. It might as well have been an IFLS link because New Atlas is similar shit quality. But what can we do?
They at least link to the company's website where much more detail can be found (Remember, this is HN, we can get links changed!). If you're going to dismiss a technology, I'm saying be specific (Remember, this is HN, we have engineers and people with actual expertise. This is a technical website, be technical!). I don't know enough about this tech though I do have experience in physical engineering (I'm not in ML, so I'll keep any strong claims to that area).
I can't say much, but at least what I can tell is that the Voith Schneider is made by a single company (according to Wiki). If all this is is a different enough Voith Schneider motor and now there is competition in the space, I'd be okay with that too and wouldn't phrase it like the OP bur rather make this the point and note that the rest is market. But again, I don't know much about motors and even less about marine motors, so I'm not really going to make any hard claims because I don't know. But if this is all that it is, I think my point still stands and you can make a reasonable enough inference of the main point to adapt to competition and improvements (which again, are small steps). Clearly this isn't an exact clone.
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.