This inside-out design solves most of the rotary engine’s problems
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I wonder how much a hydrophobic toroidal propeller would increase its efficiency beyond what's found.
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The article says it's lighter, cleaner, and 8% more efficient. It has to be much cheaper to manufacture, so hopefully it's cheaper too.
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This company/design has been issuing press releases since 2014 https://news.mit.edu/2014/liquidpiston-small-efficient-rotary-engine-1205
They crowdfunded a project to sell drone engines 5 years ago https://wefunder.com/liquidpiston/buzz
Weird that ars is writing this article as if this is some recent breakthrough rather than a 10+ year old concept still struggling to find its business case.
They crowdfunded a project to sell drone engines 5 years ago https://wefunder.com/liquidpiston/buzz
Weird that ars is writing this article as if this is some recent breakthrough rather than a 10+ year old concept still struggling to find its business case.
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I see this argument a lot, and I would say the answer is probably that some form of technology didn't exist when the idea was first thought up. For example, there are many duct designs I've seen recently that are only possible through additive manufacturing, such as those on the SpaceX Raptor engine. It's also possible there's a new material available, or a new welding technique, etc... It's crazy how many things are possible today that weren't possible even twenty years ago.
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Between Achates' opposed piston engines and this, the future of internal combustion engines is going to be... weird, to say the least.
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I've been following this engine for a while now and it feels like following the development of fusion or graphene. It seems like this engine can do anying except enter production. Is there some critical flaw with this engine like endurance, a very narow power band, or something that makes it expenive to produce? Or is it just a genuine lack of interest and the intense focus of the transportation sector on electrification?
I think the idea is really cool, but then I think rotary engines in general are intersting too.
I think the idea is really cool, but then I think rotary engines in general are intersting too.
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What about a three-lobed piston in a four-lobed chamber? Would it make it better or worse?
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It's a great design that is held back by their insistence on licensing it instead of producing it. They're hoping manufacturers will gamble on their engine.
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MedicinalGoat
Ars Centurion
But does it sound cool? The R26B in the Mazda 787B sounds like a thundercloud composed of righteously infuriated hornets wigged out of their gourds on stimulants and dispatched by an angry god to let mortals all over the world know what's up and to get on with the groveling. The gains in efficiency and reliability are neat and all but don't forget about the aesthetics!
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It sounds like they are in production for the military at a small scale. To get through procurement for a full fledged replacement of existing military portable generators would require a strong history of reliability and proof that 75% weight savings with 8% efficiency gains is worth the cost.
The consumer market will take even longer, since they need to refine the generator for emission requirements, which is why they are raising money again. Probably at least another 5 years before you can order one.
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I'd hope so because Liquid Piston has been issuing press releases about the engine 'coming soon' bit for better than 15 years now.
Mazda literally discontinued the 13B-MSP, redesigned and shrunk the entire thing, and beat Liquid Piston to a commercial mass market practical application with the 8C engine. I really hate to dump on Liquid Piston because it's a pretty cool piece of engineering, but they've been subsisting off research and proof of concept money for quite a while now. You'd think the engine would be in use somewhere by now after all that time and money.
Edit: 8C engine, not R-EV engine. R-EV is the vehicle designation.
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It looks interesting. Good animation on their site. There are still seals between chambers, but stationary ones that may not experience as much force with combustion. One added complication they don't mention is that the air intake and exhaust both travel through the rotary component. How much trouble does that cause?
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I would also say that it would be appropriate to ask in this sort of scenario, especially if they only want to embed a portion of a video. It is just polite and respectful to the youtuber.
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RickRoyLeonPrisZhoraRacha
Ars Scholae Palatinae
Can they stack-connect? Like a 2 or 3 wankle/rotary, can these be nested in pairs or more? or does the intake/exhaust limitation mean...no?
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A piston engine goes boing boing boing boing, but a Mazda goes mmmmmmmm.
View: https://youtu.be/TKIIg-MVlpc
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So who put their money on post #57 for the "ICE are a dead end, the world is burning" non-sequitur?
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One thing I would be interested to see is how this performs in a generator scenario in fuel efficiency with various types of fuels compared to traditional generators.
For small UAV's the trade off likely makes a lot of sense, since one way to improve aircraft efficiency is to drop mass. But outside of scenarios where you're space or mass constrained does it make sense?
For small UAV's the trade off likely makes a lot of sense, since one way to improve aircraft efficiency is to drop mass. But outside of scenarios where you're space or mass constrained does it make sense?
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It is not a youtube video, it is their company site (or some CDN they use).
Taking the marketing video from their site, and putting up a clip, is something I would ask about as well.
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The bottom of their investor page has 2 looping graphics which are easier to understand.
The inside triangle and the inside peanut are the things that spin.
https://invest.liquidpiston.com/?tnames=lpihomepage
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I mean it really doesn't matter the source. I was just taking the OP's statement that it was a youtube video.
There are times that it is appropriate to take footage like this for the public public, but I think that this is one that would be rather hard to justify.
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Modern submarines use pump jet propulsion not traditional screws.
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I wonder if companies are just waiting for the patents to expire at this point.
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We may get there soon for most land-based usage, but anything else (especially aircraft) will be burning fuel for the foreseeable future. More efficient engines are a net benefit while large batteries remain large and heavy.
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They're talking about toroidal props here, not engines. Also, Air Independent Propulsion is a thing. Also, even with AIP, electric subs need to run engines at the surface to transit and to recharge batteries, so a quieter, more efficient, more compact engine would be highly desirable.
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Well, they're testing currently with hydrogen vs carbon fuels, so that's already something. But even still, reducing emissions where there isn't a valid alternative to ICE is still a benefit to the world-at-large, and if it can easily be tuned to any fuel, as seems to be the case, then other non-carbon fuels that come about over time would be an easy gambit for them.
Given the vast research into energy-dense, non-polluting fuels going on around the globe, it seems like a decent outlook.
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The source matters a little bit.
I do not know if Ars has enough readership to be a problem for their server (or if they are actually using a CDN for this, which is likely on a video for external use), but traffic could be a concern.
Youtube also shows ads or at least lots of stuff after an embedded video trying to get you to do something to make someone money. There is at least an implicit assumption that they want more views just to get more views. On a company website for a product or support each one will instead cost some trivial amount of money to serve. It is not a lot per item, but it is a small cost rather than a small benefit when you view it.
If it is to be a new video only showing some of it, there are some copyright concerns as well.
It would probably be a little bit worse than linking to a specific part of a youtube video overall, and maybe they will even get a more substantial response. I first saw this quite a while ago, it has been under development for some time.
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I have definitely seen this design before. I can't recall what web site it was, but it was the same overall design with a peanut shaped rotor nutating within a triangular chamber. It was about 20 years ago.
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Any combustion engine, including this one, is really noisy.
Looks like fuel cell are a better choice for non-nuclear subs than noisy internal combustion engines https://www.usni.org/magazines/proc...ectric engines are,more than any other option.
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I’m having a hard time seeing what new technology would be needed to make this engine design viable. It looks, to me, like a cross between a wankel and a wobble plate/swash plate engine, both of which have been around for about a century.
My gut tells me that so much optimization has gone into standard reciprocating engines that an alternative geometry just will never be able to catch up. I also think there might be a hint in what the liquid piston folks talked an about with cold walls of the wankel combustion chamber. I wonder if, with the liquid pistons design, the relatively cooler rotor will create emissions problems that are hard to deal with.
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normally butters
Ars Praefectus
Most nifty, atypical ICE designs will struggle with NOx regulations in the automotive sector. You try to get higher combustion temperature or pressure, you try to reduce weight, you try to increase fuel efficiency and reduce carbon emissions, and if/when you succeed, the remaining downside is higher NOx emissions. We lived through this process a couple decades ago with stratified charge gasoline direct injection and (more memorably) common rail turbodiesels. These designs made improvements in several areas but could not deal with increasingly stringent NOx restrictions.
UAVs, stationary generators, perhaps landscaping equipment... There are plenty of sectors where an engine that does everything well except non-CO2 emissions can currently succeed. But breaking into the automotive sector, especially while the automotive sector is working toward a post-ICE future, seems unlikely. Breaking into (piloted) general aviation with a novel engine is horrendously difficult for different reasons. Outside of those sectors, there are much better opportunities.
UAVs, stationary generators, perhaps landscaping equipment... There are plenty of sectors where an engine that does everything well except non-CO2 emissions can currently succeed. But breaking into the automotive sector, especially while the automotive sector is working toward a post-ICE future, seems unlikely. Breaking into (piloted) general aviation with a novel engine is horrendously difficult for different reasons. Outside of those sectors, there are much better opportunities.
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Not precisely true (otherwise all the fish would die). It's just that the oxygen in the surrounding environment is inconveniently mixed with wet stuff, and also present in a lower ratio than in air. And I believe that there are fueled submarine designs today that either surface/snorkel (in order to access air for the combustion) or use an on-board oxygen supply (the Swedes have a submarine which carries LOX).
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Landscaping equipment seems like an ideal area to move towards a post ICE future. Especially in environments where the equipment will sit unused for six months of the year. Electric motors handle that better, and motors are generally more reliable. Especially as battery prices continue to come down and the fact that California is transitioning to electric in this area.
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