How It Works LiquidPiston X Engine
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- Опубликовано: 11 сен 2024
- LiquidPiston’s X Engine is a non-Wankel rotary embodiment of the company’s innovative High Efficiency Hybrid Cycle (HEHC). The X Engine has few parts and three combustion events per rotor revolution, resulting in tremendous power density.
• xTechSearch 3 Finalist...
Inventor Alexander Shkolnik
They are claiming 50% thermal Efficiency.
BEAT THAT STIRLING ENGINES !
liquidpiston.com/
Let me see your design for getting 2 HP from a 5" diameter Engine on pump gas and 4 stroke.
vimeo.com/9900...
wefunder.com/l...
see also
• See Thru Liquid Piston...
And Watch Intgeza Visit the factory !
• THE LIQUID PISTON ENGINE
Recommended Study to understand the principals here :
Carnot efficiency (Thermal Efficiency)
• Physics 29 Efficiency...
PV Diagrams
• PV Diagrams
Wankel Engine differences:
1./ Centre "piston" is ovoid not tricloid.
2./ Housing is Tricloid not Ovoid.
3./ Apex seals are stationary in the housing.
4./ Expansion ratio is larger than compression ratio - see Atkinson Cycle.
see description
Why, oh why can't we see a slower animation, with the parts other than default grey, and with the front cover not in the way?? I'm still not clear on what is going on here.
Has Mazda considered this engine for their range extending application? It seems to beat their difficult path of getting their wankel to work well enough.
@@someotherdude Click that gear icon at the bottom of the video window, and you can play back at half or quarter speed. I like to see better labeling and a better explanation of key features that make this different from a Wankel, aside from just that chamber in the rotor.
Warped Perception made a video about liquid piston rotary engines, and I ended up with a pretty good understanding of how they work
Great animation. It would be very interesting to see a variation in which the rotor is held still, with the block rotating around it, to get the operation from the perspective of the rotor. (It reminds me that early aircraft rotary engines were piston engines, in which the crankshaft was stationary and the engine block rotated [with the propeller bolted to it. So, my suggest would be a rotary-rotary engine. 😉)
@@-NGC-6302- Much thanks. That was worth a search:
ruclips.net/video/jLtyNtf9_ew/видео.html
en.wikipedia.org/wiki/LiquidPiston
en.wikipedia.org/wiki/High-efficiency_hybrid_cycle
I take it "LiquidPiston" is just a brand name and doesn't really refer to some aspect of the technology, or do I have that wrong?
So an updated rotary... I like it. Seals are on a non moving part so it'll last longer.
Whether or not the seal is physically moving is irrelevant. What if the rotor was stationary and the housing spun? Would the seal care? No. The seal wipes against another surface. Same friction either way.
Im thinking the seal probably would care as in no longer has any gyroscopic loads on it trying to force it radially outward. In this case the conventional rotary would seem to have the better setup where the physical forces being applied are adding to the seal force on the outer wall.
Why wont this thing suffer all the issues a wankel suffered from?
@@lazzer408 I think he was referring to the apex seals.
As a former NSU Ro80 owner; I can see where Liquid Piston has addressed all the shortcomings of the NSU Wankel engine.
I’d like to find an old Ro and put a Liquid Piston engine in it !
Perhaps, instead of the counter balance, have another rotor making it a twin. Then introduce the mixture in the center between the rotors and have the exhaust exit on opposite sides.
X2 POWER!
and then you could put some kind of supercharger on it to push air through
with oposed exhausts like that you could have turbos dirrectly onto the intakes.
Boost comes in, and finally apex seals don't come out.
@Austin T. They want to keep things as simple as possible. The exhaust would have to be rerouted as it goes directly into the other rotor then. Thus just making a bigger rotor with a counter weight is "easier."
I've been working on rotary engines for 17 years of my life... but this... Needs to be perfected I want 1. Goodbye long combustion chamber. Hello perpendicular combustion against the face of the rotor. Bet this thing wouldn't chew up rotor housings. "Nail marks of the devil". Why didn't anyone think of this before?
+stompyrompy What's the theoretical max RPM of this thing? 30,000?
Answer is honestly I don't know. I love the stationary "apex seals". If I was to put this engine to use I would run it at a governed 6000 rpms. That is if it was around the size of a 13B combustion chamber. This engine looks like it was built for efficiency not huge amounts of power. Maybe a great generator, or even drone engine.
NOTHING,,, will beat Felix Wankel's design for a rotary in making hp(rotary class)
They just wear out faster than anything else
+stompyrompy They do that all right and consume nearly twice the fuel and oil in doing so. How is the capacity rated?. Two rotors and three combustion chambers each = 6 combustion chambers = 3 litres at 500cc per chamber. Cannot be anything else. Dogs !!.
Because people gave up on the rotor and it's rapid wear down/heat issues/emissions/etc.. "Let's bore it out for more combustion space!" Great idea for fans of this type of engine.
In efficiency it approaches the 5 stoke engine. Note the long expansion section. wear is not a significant factor as the motion is bearing guided and fully balanced. Injection, supercharger , and able to run on wood gas are all possible. High power possible due to high speeds that can be achieved. The weight is tiny for its out put.
As a mechanical engineer, this thing is awesome! Two moving parts and 2 hp/lb. If it is reliable, it could be a game changer across the board. This could take thousands out of the cost of every car by removing a bazillion parts.
it looks awesome but its far behind traditional engine with all the features. Also car don't have bazillion parts, but you would know that if you were a real 'engineer'.
@UCN9GpfVIbwGoajaliOF08-g shut uo you pseudointellectual
@@TheBlork74 no newer engines are very complicated for no good reason other then they have to comply with epa and commiefornia
The testing results over 150,000 km should be very interesting.
This is a UAV engine
@@GarretKrampe How many hours is this engine rated to last? With a 26 to one compression ratio, is the fuel detonating? If not, how are you avoiding detonation? How are the seals lubricated? What are the exhaust gas temperatures, both idle and under load? Can we see a HP/torque curve? Does it produce good low end torque? Whats the minimum idle RPM and maximum RPM?
@@smh9902 The engine has issues with fatigue at the moment .
@@GarretKrampe fatigue as in the piston is failing or ?
@Vaiserint it's no longer a dorito, it's now a pringle
I love the idea of rotary engines, I think they could be a very exciting lightweight solution for so many applications if they solve the age old seal problems.... I could envision an off the shelf 45-60 HP rotary that could be fitted into any modern MX bike chassis with half the weight, mass and complexity of current four stroke singles; same goes for roadracing motorcycles as well.
I like the simplicity of the engine.
I like the simplicity of the electric motors, no oils, no seals, no excessive heat issues...
This is in fact a gerotor engine, more precisely the simplest form of it, 2-to-3. The fixed outer gear calls for an eccentric inner gear. The gerotor is known for more than 200 years but only now someone has thought to make an internal combustion engine out of it. Nothing less than a stroke of genius, if you ask me. Damn', it didn't come to me first.
Lubrication makes me think it is doomed to go-karts and RC models.
Low end torque, max rpm, min prm all things I would like to know. I think this engine would make an excellent motorcycle engine. Less vibration in line production of power small, am I on track?
I saw somewhere in a video They tested at 10,000 RPM, I may be wrong but I think it went up to 15 or 20,000 RPM in the video I saw
its the same as the wankel engine but with inverted shapes
Yep. Instead of putting a dorito in an oval chamber, it's an oval in a dorito chamber.
@@iloveanimemidriff yep, and it saves the seals too.
This is a UAV engine , nothing like the wankel . look where the seals are for one and the shape .
@@GarretKrampe No its a general purpose engine for every thing from drones to Generators maybe even to cars.
It has related geometry (based on curves formed by circles rolling around circles), but is certainly not the same.
It has a main difference from the Wankel, the combustion chamber move at each rotation, so less heat stress.
True now it's firing at all three sides of the housing instead of on just one side like the wankle
But all the combustion happens on the same side of the rotor
I did my mechanical engineering thesis on the Veselovsky rotary engine, identical to this design. Calling this a "revolutionary new design" is absurd; it's been around since at least the 1980's. Like the Wankel, this engine will still have the problem of lubrication on the seals between each chamber. The huge chamber surface areas mean that a lot of the combustion energy will go out of the system as waste heat. Keeping the rotor light and still preventing warpage from the hot and cold side being so close to each other would be a challenge. There are many others. I had very detailed CAD models and had enough of the thermodynamics figured out to consider trying to build a prototype, but I'm glad I decided to move on to other projects. Good luck to those who start building this - you've got a lot of work ahead of you.
The problems with this and the Wankel are well documented: Poor thermal efficiency, and large "swept" areas leading to flame quench and sealing issues. As a driven pump, it may have some value. Positive displacement and smooth flow characteristics look likely. The piston engine has been refined to the point of extraordinary efficiency. Tough to beat it.
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Ok but rotary go BRAPBRAPBRAPBAPBAPBAPBAP
Whoa...so you eliminate the complexity of a traditional 4-cycle(valves, cams, springs) while retaining a 4-"stroke" cycle. I have known how the Wankel works but this is very cool...this also makes 3x combustion chambers instead of needing separate intake-compression/ignition-exhaust 'chambers' like the Wankel.
Looks promising so far, specifically high compression in a rotary type engine and the interesting transfer ports in the rotor. About this video... ask me to fix it.
The counterweight should be split to both intake and exhaust sides, being on one side will cause an uneven torque on the shaft it's there to balance out.
Inverted Wankel, I believe he solved many of the flaws, thats very clever. When the Wankel finally comes of age, it will sit right here, with the turboprop!
Agree totally.. I owned an Ro80. Awesome experience; but with downsides. Liquid Piston appears to have addressed those !
Look interesting, but it also looks like it would share two of the Wankel problems.
Lots of surface area to try and seal, and combustion immediately transitioning into exhaust which gives great opportunity to unburned fuel to simply escape.
A superb version of the rotary. Everything about it looks good.
8 years later still no mass production... looks like it will remain as a good idea since the electric cars are taking over in few short years!
@@goru426
Seems that way. It is produced being used by the US army, although produced only in small numbers. It may find its way into drones.
@@johnburns4017 You are right, I never thought about military applications. I've been told that turbocharged diesel piston engines work best for high altitude drones. If high altitude is not required this engine might be a good solution.
@@goru426
It is supposed to be economical _and_ light.
Absolutely genius! The problem is you have brought it down to such a simple form that people look at it as "so what's the big deal", and are unable to appreciate it for what it is. But, that was what was genius! Too bad the reward is lack of appreciation.
So a Wankel engine with an untested valve replacement variant. Build one and test then let us all know. GL
They've used a 4hp version in a go kart haven't they?
ro63rto Not sure?? The problem with Wankel engines are efficiency, seals and uneven wear.
Yeah they showed it off but it's like 15 seconds of driving and they only said "3 hp @ 10000 rpm" which is really unimpressive by todays standards even though it's small.
The thing they built is 70cc, and 3 hp @ 10000 rpm which is really unimpressive when compared to a regular two stroke 70cc engine with an expansion chamber, those usually reach upwards of 7-8 hp on variants built to last with more extreme tuning yielding closer to 15 hp.
The only real benefit I see with this compared to a regular wankel is more even wear and no need for an expansion chamber, this thing would still eat oil and sot up like a regular wankel though.
I like how compact and light weight it is though.
*EDIT:* Also they don't even show a hp/rpm curve, might as well have basically no torque for all we know
Also in that video when installing it on the kart they are using a jack shaft, in the footage of the kart running, no jack shaft.
Well.. you can see in the vid that they at least tested one of 40hp.
This is really interesting. With its small size and weight. I can see it being hybrid it with an electric motor. Goodjob
Cool video. My concern would be compression leakage down the sides, also an always open EGR due to no way to remove exhaust in turn lowering A/F mix. Maybe I missed something but that's my thoughts.
What's the Brake-specific fuel consumption? Models are great, but you need to build it, run it on a fully instrumented dyno and see if you really have a better mouse-trap.
It can not compete against electric cars... that is all you need to know.
I would like to see a small version of this made to run on "nitro" fuel for use with RC airplanes.
Golly do I have some news for you.
Dude... Rc airplane? I fly rc airplanes and I am a petro head and I can tell you than no matter what no combustion engine can compete with modern electric motorc. Power to mass ratio is just in-fucking-sane. Dudes have 100"+ wingspan airplanes that require at least 100cc gas emgine but instead they have a tiny electric motor.
@@theprinceofliberia6793 So no battery then, just a tiny electric motor?
@@ferrumignis yes they have battery of course. For performance you want electric because it is the cheapest and least complicated.
Has the heat loss during the constant volume part of the cycle been factored in? As there is no expansion during this phase and no work being produced, how is the heat of combustion being contained without it leaking out through the casing walls or into the rotor to further dilute the weight of charge by reducing its density? That rotor is sure gonna get mighty hot!!! Will it still seal and not seize?
+Paul Ellis it's just a model and it also has no exhaustpipe but those parts are needed on the most combustion-engines don't you agree ?and seal or seise is a matter of precision building with the right materials like ceramics plus Alexander Shkolnic claimes 50% thermic reduction,but what i like to know is the testing on a dyno blazing out 40 h.p :how many RPM's are used in that film or how many rpm s are needed to work properly ?
frans venrooy I'm sorry Frans, but "precision building" is not the answer for fits and tolerances. Sealing and cooling any rotary engine is highly problematical, as is lubrication. Ask me, because I have built one already!!!!
I have examined many rotary concepts and most remain just that........concepts! The Doyle rotary, the MYT (mighty yet tiny), the Libralato, the Wankel, the Orbital, all these immediately spring to mind and none were commercially successful. Throwing money at rotaries is a great way to bankrupt oneself!
If it doesn't work using conventional steels and alloys, it sure aint gonna work with fancy coatings and ceramics either!
(P.S. I design and develop engines for a living, by the way.)
Paul Ellis their other videos show it running and compare heat vs normal rotary engine, and this stayed like 1000%. cooler than a normal rotary engine.
There is no constant-volume part of the cycle at all, despite the claims in the video. The eccentric shaft never stops turning, so the rotor never stops moving, and the rotor doesn't pivot around the center of curvature of the end of the rotor so it isn't simply turning in place with unchanging volume. This is fundamentally no different from a reciprocating piston engine, with minimum piston speed at top dead centre so the combustion chamber volume is changing very slowly (compared to the mid-stroke rate).
my first thought is that you have taken the principle of a wankel engine and given i a new twist, so to say its a non-wakel engine is a stretch
The idea of the spinning rotor is the only thing similar. The exhaust, the explosion, and intake are all different, as the rotor regulates exhaust and intake, while there are three explosion chambers instead of the wankel's one.
in efficiency it approaches the 5 stoke engine. Note the long expansion section. wear is not a significant factor as the motion is bearing guided and fully balanced. injection, supercharger , and able to run on wood gas are all possible. high power possible due to high speeds that can be achieved. the weight is tiny for its out put.
perfect engine for a generator - range extender
Claiming something in no way makes it real. I suspect the specific fuel consumption or efficiency will be lower due to exactly the same problems the trochoid wankel had, such as terrible combustion chamber shape (one reason two plugs were required). The wankel had some neat capabilities like high output/weight and mechanical simplicity (essentially 3 moving parts for flow/combustion generation), but efficiency was NOT one of them. The wankel can be modified to work with several shapes bit I don't think it will fix the inherent issues.
+John Sikes The very poor combustion chamber shape on the Wankel meant that it was difficult to light it up efficiently. Lubrication and sealing has been a never ending problem and has never been properly addressed because of the flaws in mechanical design. This all added up to 20MPG however you drove the Mazda Wankel, and poor emission control. I cannot see how this new X engine can be any better overall. It has several inherent problems just like the trochoid Wankel. Total loss lube system for a start. Low emissions means no oil burners. We will see.
+Crobular I Actually my son got 30 MPG out of a 85 RX7 GSL SE (13B) coming home on the highway at 50 MPH, cruise control on, in Fl. (no hills), so it's possible, but only with the most extreme careful driving ;-). Being stuck on I95 and calling us to have to come get him is pretty good motivation, I guess.
Yes, the rest of what you say is true, except that the lubrication/sealing problems were pretty well addressed with the millions of man hours Toyo Kogyo put in to develop the ceramic multi-piece apex seals that took the life to routinely 150 K miles or more. My engines (I've owned 4 RX7's of different generations, HP buildups, etc.) almost always failed either due to loosing coolant (one, to a blown radiator hose) and the side rubber o-rings loosing seal, or to the Orings in the Housing to center case oil transfer ports, they would just ooze oil worse and worse until it was impossible to ignore. I don't think it will ever be a viable alternative soon in increasingly more restrictive emissions/economy. But with a Tesla sedan electric out there that destroys pretty much everything out there streetable 0-60 (I think it's something like 2.5 seconds), so it will be with internal combustion in general, I think. The future for cars is not IC centered.
+John Sikes 100% agree that innovation will probably not come in the form of a better internal combustion design since electric cars have now dramatically exceeded them or matched them in every way that matters. What Tesla has done groundbreaking.
+Andrew Somerville electric cars existed before gasoline cars existed. Read up on some history! Telsa makes them flashy not ground breaking.
+Brian Gochnauer Actually what Tesla did is groundbreaking. I think Andrew was referring to the fact that Tesla produced an electric car that has more performance than virtually every production piston car out there, rather than the fact that it is electric. That is definitely groundbreaking, as he is the first to do it with a production car.
The best engine ever !!!! WOOW :O
Thats great.. so this has been out for few years now. Wheres the real test video?
+Atanas Tripzter it can't be released probably. Most revolutionary engines that would provide higher efficiency are shut down quickly. Take the duke engine for example.
Smokey Yunic made cars in the 80s getting 50-60 mpg and 0-60 in four seconds and that was with four and three cylinder engines without advanced timing systems. The world is much larger and filled with many ulterior motives. We are held hostage by our greed.
+1InfinityShade You know that if they ever made a car with 80mpg they would just up the gas prices right? That way they make the same profit, yet their limited oil reserves last longer.
I know. Ive looked into all the effects it would have on stocks.
+1InfinityShade Also the car you are describing, there is no proof it existed. It may have existed, but likely not.
And what nonsense are you saying about stocks? All a company has to do is patent that mythical engine, and their cars would be the numero and they would make BANK everybody would buy that company's car. They could sell it for a ton too.
Yes, we also make money on oil. Yet all they have to do to maintain profit is drive the cost of fuel up. Businesses who sell diamonds do the same thing. This increases profit, as well as makes their limited supply of oil last longer.
I see no logical sound argument that could sufficiently support your theory that there was a mythical unicorn car that was hidden from the public.
Its not that simple. We are the import nation. The purchasing of other nations products fuels the econemy. When we buy less oil the price of food in russian goes up over night. Not to mention the executives who hold shares in oil hate to see their numbers down. If you dove into how the economics of the world work over how the U.S alone works you would see some interesting factors. But going back to the engine... I have sever years of engineering under my belt and Ive found that there are many engine designs that function better, last longer, and produce less emissions. The issue is that these engines are too effective and would put many mechanics and oil companies in a bad spot. Then the other companies would have to invent a product to try and keep up. Ultimately many people would loose their jobs and go homeless as well as the damage it would do to the supply and demand of petrolium based products. We really are in a bind, not just the U.S but all of humanity. I have one solution for this but it is beyond the scope of sciences we understand.
Rotary engine issues are back in a brand new design! :D
Emissions issues, sure. Probably less problems with sealing
@@soundautomatic1 The lacked of changing geometry during combustion phase might address the emission.
So I think its the same with wearing but with less emission problem.
The engine I heard has higher efficiency.
Still no way to oil this without putting oil in the combustion chamber.
Yeah sad story, have a really bad fuel economy probably too.
yup, same Wankel rotor sealing and lubrication and pollution issues ... this design does solve one Wankel short coming, that of the hot combustion occurring only on one side of rotor cavity, here combustion is distributed to 3 evenly spaced locations, so compared to a Wankel, the distortion & sealing issues would be less problematic. Sealing and lubricating a round piston in a cylinder is simplistic & easy to manufacturer ... if a new engine design for passenger vehicle use cannot start from the point of improving on this, there is no sense to go much further, lol.
Don't pretend to be an expert. You are an idiot.
@@GarretKrampe lol it had to be said lmfao thanks for saying it for me
At least the seals are stationary and aren't subjected to the Wankel's extreme temperature variations. But yeah, the question remains, how do you lubricate the things?
The name needs a lot of help. It is not shaped like an X and there is no piston, much less a liquid one. I would call it a version of a rotary engine. In this case, does it have the same problem burning oil that plagued the wankel? What is a typical configuration? Single stage like this one or ganged multiple stages? What kind of mileage does it get? I would love for this to be cheaper, more fuel-efficient, and more reliable than what is out there today. Just need more info, please. Thanks!
The company is called liquid piston. Although I agree that it needs a better name than X.
Since the apex seals are stationary, I don’t think it’s an issue.
I've been watching liquid Piston for years..where are the lawn equipment they have promised. If it can do what they say they can then where are all small lawn mowers and chainsaws, weedeaters and blowers would be useing them
Just a new version of Wankel...
This might be a great "sustainer" engine for sailplanes
Been done. You can either put a triangularish rotor in a elongated circle shape (wankle), or an elongated circle shape in a triangularish shape to do this sort of thing. Your use of ports inside the rotor may be somewhat novel but the elongated circle inside a traigularish...block has literally been done before, actual functioning engines. They are no better than the wankle in terms of power density, thermal efficiency or emissions. They can be as good, it just depends on the seals, tolerances and coatings. It is a good power density compared to a piston 4 stroke but bad w efficiency and emissions. Good try though.
+John Smith exactly! But from what I can see this has a downside compared to a wankel. With a wankel the apex seals are centrifugally driven and the apex seals in this designed appear to be in the block and therefore have to be mechanically driven thus reducing reliability in an unreliable engine.
This is litterally the inverted version of the Wankel... but then... great concept.
What does the torque curve look like?
I bet this engine is not good on torque, but it can make that up with very high revving. The wankel was also a very high revving engine.
I bet a butane diesel mix would work well with this. Port inject the butane, direct the diesel. The diesel is useful for lubrication and the butane can decrease charge temp until ignition at which point a high enough temp for clean burning diesel is possible. Thus you get more energy density than e85, in a form (miller cycle) proven to be more efficient than the otto and diesel cycles.
looks a lot like a rotary engine. just saying
+ryan That's because it is a rotary engine =)
I do comprehend tha.t I was just expressing the fact that it was not recognized as a engine that has been working in many vehicles for a number of years. Now it is just tweeked like many other piston engines. And to add, another fact is that there are no pistons, yet the titled states so lol
Good points. Also I can't imagine it will be any better, or at least significantly better with emissions as it will have to use some kind of oil injection lubrication for those seals on the block.
I own a rx7. U actually just premix with e85. Its cleaner bt,t by today's standards, not clean enough
@@RyuFitzgerald Seals and oil are two different things, no? Seals are there so that liquids and gasses from one part don't escape/enter another. Oil's there to libricate to minimize harm to the surfaces from friction. So if this one doesn't use oil it's gonna be a nightmare in the maintanance department
Even though it looks similar to the Wankel engine and has rotational mass like the Wankel, this is a very different pistonless rotary design and this would be awesome as a larger full scale car engine! It's weird, but hey I like weird lol! Anyways, this is another revolution in pistonless rotary technology just like the Quasiturbine engine and the RKM engine that was inspired by the Wankel and I have a feeling there will be more and more rotary engines being tested and developed in the near future. Who knows, maybe pistonless rotaries will be the future of the internal combustion engine after all. But hey, that's just my theory
So basically a wankel rotary engine variant...
Ehm.. No
+Alberto Mora nope its a rotary engine but not a Wankel. The only thing its shares is the epitrochoid formula.
Inverted Wankel
Yeah , sorta
ONLY if you feel a three piston two stroke engine is a variant of single piston four stroke engine. Or if you would think a diesel engine is a variant of a gasoline engine. Which brings the question, "How much or how many difference does it take to be a different engine?" To an engineer the answer is different than it is for a non-engineer. For someone with no knowledge of liquid fueled engines aren't all of them "basically variants? I
this idea is still born
The good part of this engine is the fact that it has a truly constant volume combustion event. That will raise its efficiency. The large down side is the seals which have to take up the gaps between the moving rotor and the engine case. Like the Wankel this engine's rotor will expand as combustion events take place on its face three time per revolution then in the interior is further heated as it conducts the burning exhaust gases away. Like the Wankel seals leak and efficiency suffers. This problem doomed the Wankel. Also I doubt the 75% efficiency numbers.
It doesn't have a constant-volume phase at all, despite the claims in the video. The eccentric shaft never stops turning, so the rotor never stops moving, and the rotor doesn't pivot around the center of curvature of the end of the rotor so it isn't simply turning in place with unchanging volume. This is fundamentally no different from a reciprocating piston engine, with minimum piston speed at top dead centre so the combustion chamber volume is changing very slowly (compared to the mid-stroke rate).
This vid is terrible at explaining how the thing works.
Just because you don't get it, doesn't mean it's terrible (video, that is).
+Zero Sum Game
No, that's exactly what it means. A proof of concept video exists to explain how it works, simply, to investors not engineers.
In this video the engine would not work. The combustion chamber is not sealed at all to sides of the 'rotor'
+Ben Lucas
Look at a Wankel engine, same exact concept and they seal just fine (for a while, but we aren't talking about reliability here)
Look at engine in this video and my comment again... I am very familiar with mazda wankel engines... This engine animation has no components at all to seal between rotor and end plates (side seals on a wankel) It would not work at all as shown here.
Could you eliminate the need for a counterweight by lining up three of these so that each one is hitting one of the three ignition points at the same time?
Theres so much contact area on each "lobe" that it CANNOT be efficient. Way too much friction.
LESS contact than a conventional piston engine, it looks like to me.
You may be forgetting the side walls too... not just the apex seals in contact
it would still have less friction losses than a piston engine
If I'm understanding this correctly, there are 3 power cycles on one rotation of the crank. I'll have to look more into this. I know that was one of the problems with the wankel...it caused a lot of heat.
No, there are three power pulses on each rotation of the rotor (piston), but it takes two eccentric (not "crank") shaft rotations to turn the rotor through one full rotation, so the result is three power strokes per two shaft shaft rotations... just like a conventional three-cylinder 4-stroke reciprocating piston engine.
From my perspective as a student of engineering, this is an extremely flawed design for todays standard, since in order to run this, it would require going back to inefficient vacuum operated carburetors. Also, with the way the eccentric shaft moves the rotor within the housing, there will be premature wear on the block, which is catastrophic, causing need for a whole new engine (portion).
+_Husky Why are you under the impression that it would need carbs??
Kj16V the fuel enters through the front, instead of being controlled by valves. A drop-needle carb would be required in order to regulate fuel flow, since there is no cam to operate any valve. In that, excess fuel would cause the mixture to be too rich, and since there is no mediation, the engine would flood in one sector, and cause hydrolock. This engine is not going to make it into production for these very reasons.
_Husky How many production vehicle engines still run on carbs? Google "EFI" :D
Kj16V EFI runs off of a pressurized system if which does not have the needs satisfied by the current engine. There needs to be valves in order to prevent flooding. That of which this engine cannot provide. There is no valve system, no overflow protection, there arn't small enough injectors, or injectors that dont require any backpressure at all even to this day. The only apt way to power this engine is via carb.
This isn't meant to sound at all rude, so please don't take it as such, but your understanding of valves, injection and carbs are very, very wrong! Please do read up on electronic fuel injection Fuel injectors don't need valves to stop flooding, they meter the required amount of fuel by pulsing rapidly, regardless of whether there is a valve there or not. They also don't need any back pressure (I have a feeling you're confusing back pressure with something else). Also read up on "direct injection" - This injects directly into the combustion chamber, no valves or anything.
Valves have nothing to do with overflow protection, they're there to allow air in, exhaust gas out, and to seal the combustion chamber on the compression stroke, that's all.
Having said all this, this engine would work just fine on carbs - Wankel engines do and they also have no valves.
It's an inside-out Wankel :)
Rotary engines are cool and all, not to mention clever, but the piston engine has a huge advantage: It has the least surface area in the combustion chamber for a given displacement. That means it wastes less heat--piston engines burn less fuel for a given power output than other types, and it's easier to control the emissions as well.
That's why nearly every car under the sun has a piston engine--it's not because car companies hire engineers that don't know anything about rotaries. It's because they *do*.
So this is like a rotary only worst.
The biggest issue I can see is how do you intend to port the intake or the exhaust?? Especially on one that has more than one rotor. The headers would have to look like something out of industrial art.
Wankel 2.0 hahaha
All people associate this engine with the wankel but I think it is totally different and much more efficient congratulations to the creators.
Wankel replica..... almost same engine ..... known problems. Electric still the best.
May be the best, but surely the most boring and range limited
cesare vissani
Boring absolutely not (TESLA ROADSTER), Range limited, yes .... but soon it will change.
mptrax Booring anyway, electric is too...
When i buy something, i want to be able to fix it, nuff said, i dont like fuel injectors, i like carbs and simple, tested, rugged stuff, Electric may be the best energywise, but surely not funwise
cesare vissani
Oh sorry dude. I didn't understand You love medieval engines. Joking Dude. Electric not funny ? ahhaahahahah !
Dude ask to those who brought a BRAMMO IMPULSE or a TESLA ROADSTER SPORT.
On a drug race they DESTROYED literally car like CAMARO, VIPER, FERRARI, PORCHE, BMW. Electric engines simply have TOO MUCH TORQUE... really TOO MUCH !
I can't love carburetors dude... cause they need to be set up close to the sea... and need another set up on the top of a mountain. They are absolutey not accurate.... there was a time I loved them too... but those time are gone forever. cheers.
mptrax What i really meant is " your gas cable broke" 5$
"Your super advanced drive by wire pedal is broken" 400$ + 100 for the guy replacing it,
Electric might be better for showing off, till your computer, batteries, whatever overcomplicated electric device is broken, then the thousands of dollars start to roll, piston engines (and maybe rotaries too) are just simpler, and they have something electric engines don't have, A soul, knowing how every part of the car you are driving works, listening to every stroke of the engine, for me, that is the essence of having a car. It really isn't just a way of getting from A to B
It's almost like food, you need food to survive, you could eat perfectly healthy, tasteless food, or you could eat something you made, that has a taste and that love was put in.
You can choose what you want, maybe electric is the way, but I surely hope it won't be in my lifetime.
p.s. = i saw a guy give total shit to a tesla S, in insane mode, point given he wasn't exactly stock...
an improvment to the design to aid in breathing would be to use both a variable geometry turbo charger as well as a tesla turbine. Set the turbine to be directly powered by the crank and have it's disk side ports directly connected to the exhaust ports on this engine and then have it's tangential ports go out to the variable geometry turbo charger
Soo, turbocharging, but off the crank shaft? Sounds cool.
adding propellers in front of the counterweight could maximize the cooling of the motor and the amount of air that can enter it, improving even more its performance
WHOAAAAA!!! That's so freaking clever!!! Theoretically it's looks great and looks very efficient.
Love how all these wannabe faux engineers making comments on how this engine won't work and what a failure it'll be. Where's your engine design or degree in engineering for that matter?
+John L (RLst) It's almost a Wankel engine (the idea of an eccentric rotation instead of reciprocating pistons). The main difference is in the shape of the rotor. (Wankel used some triangular like shape in oval housing instead of using oval shaped rotor in a triangular housing like this.) And the exhaust ports are placed on the side, not on the back walls.
The mayor problem with these designs is the shape of the combustion chamber.
A relative wide and flat chamber leads to imperfect combustion which means bigger fuel consumption and worse emission characteristic (Mazda had some models with Wankel engines). However the power density of these engines is better than the conventional piston engine's.
+Péter Kiss Looks like they approached the combustion chamber problem by compressing the mixture into a pocket around the sparkplug. Once ignited gas expands, pushing the rotor along the way. What isn't clear is how this rotor seals and if they have to pump oil into the cycle to lubricate the seals.
+grayswandir47 This design solves the uneven heat dissipation problem that causes sealing problems in Wankel engines. In a Wankel there is a cold side on the intake and a hot side on combustion. This causes the case to heat unevenly. This design has three combustion chambers which distribute the heat more evenly.
grayswandir47
"This design solves the uneven heat dissipation problem that causes sealing problems in Wankel engines."
That's right.
"Looks like they approached the combustion chamber problem by compressing the mixture into a pocket around the sparkplug."
That wasn't a problem even with the Wankel itself. But the fuel needs time to be combusted fully. And the shape of the chamber (and the gas in it) trough the expansion differs from the shape of the pocket. Even the Wankel has pockets on the sides of the rotor to form an acceptable combustion chamber, but the chamber itself has a worse geometry and volume/surface ratio (which leads to more heat loss trough the walls) compared to a cylinder of a piston engine.
The ideal chamber would be a compressable/expandable sphere. The more it differs from that geometry the less efficiency can be reached.
+Péter Kiss mabe make it a diesel then and inject the fuel instead of a spark plug.. although a engine like this might not be able to create that hi of compression
i remember my old classes of thermodinamics. the efficiency of a otto cycle has the folling expression: n= 1- Tmax/Tmin. where Tmax is the maximun temperature in Kelvin or in Rankine degrees and Tmin is the mininum temperature of the cycle as well cause the designer change the geometrics of the rotor, in order obtain a total combustion in a constant volumen, This increase the thermodinamical efficiency of this cycle, gaining power of the gas. this is the secret of this motor, an amazing and genial idea. it is not perfectioning the mechanical aspects of the engine, it is perfectioning the thermodinamical cycle, it is a very deep concept.
That's not really an Otto cycle efficiency, it is the efficiency of the theoretical Carnot cycle; that is the maximum for any heat engine. There is nothing about this energy which improves the maximum temperature and exhaust temperature relationship, so it has no inherent efficiency advantage.
en.wikipedia.org/wiki/Carnot_cycle
Can it be solve a problem from rotary engine concept that have leak in compression stage.?
One question i have.
won't this engine have the same problem with the wankel engine? the seals being need to change often?
I've been developing a similar design around 2010. So i get you completely :D Plus had some improvements over the one shown in the vid. :D
one of the disadvantages of the old wankels was heat as theres no cool down like in a 4 stroke. Im curious if this engine will output heat like crazy having constant sequential ignition.
They claim they could do one round of air if need be, dunno if that's a reasonable thing to do.
Was heat the issue or uneven heat distribution the issue? I think that having the intake in the rotor will help some on an air-cooled engine but at the end of the day definitely needs to be liquid cooled imo
I don't see why they couldn't slap a nice radiator on it though so cooling shouldn't be an issue 🤷🏽♂️
this idea seems to have a thermal efficiency much higher than wankel engine, great job!
doktorbimmer if you see how it works a wankel engine then, yes
thats what im saing
I think it looks cool, but then again I still like the old Mazda rotary engines so I may very well be out of touch :) Let me know when they put one in a sports car.
Sure it's not too different from the Wankel rotary engine but it still looks interesting nonetheless.
This can be used in small engines like lawn mowers, snow blowers, etc. which is a huge market as well.
It looks like a rotary engine?? I like it, hopefully it is more efficient than the rotary which is now dead.
The geometry of the rotation looks like it won't work. The animation of the rotor overlaps the housing.
Michael Cain During the camera move, the piston projected out of the housing. You're probably seeing spatial occlusion, not clipping. In other views where it makes no sense to do that, they might just be hiding the exact profile while they secure the IP. It's no simple pill shape, but there should be some solution.
Michael Cain There was a working prototype on Vimeo.
...becasue we still haven't collectively learned our lessons from the Wankel yet, here is an even harder-to-seal-version with ovals instead of triangles!
Nothing beats a real world prototype.
Proof piston engines are the engine of choice ONLY for the reason they consume more fuel: with their back and forth motion and sliding rings within cylinders. Reversing momentum, friction, and then waste all the heat out the exhaust pipe and radiator. I have no doubt this engine would make any piston engine look like a sea anchor.
nice concept for different fuels u will just have to take engine with different means small or big sized rotor👍👌👌.
I love seeing new thinking like this!
Before bashing this engine. It got 1M from Darpa so this is real deal and it's mainly designed for drone use. You can go back to eating doritos now.
DARPA funds longshots, its sorta the entire point.
A military system will trade off insanely high maintenance cost for just one peak area of performance. WWII era gasoline engine in fighters had flight times measured in dozens or hundreds of hours, totally impractical for any other use save that critical peak of power for a few seconds that won or lost dog fights. By contrast, diesel aircraft engine had flight times measured in the low thousands of hours and some steam engine (practical for huge flying boats it turned out) measure flight times in high thousands or even tens of thousands. But both useless in military aircraft because of their weight.
Frankly, I have yet to see a "new" IC engine that isn't a minor variant of a 19th century hydraulic pump or an attempt at a rotary steam piston/turbine. Through in some in/out fuel/exhaust valves and spark plug into almost every hydraulic pump design ever and you have a "radical" IC engine. The wrankle engine had dozens of pump variant predecessors. There are literally thousands of patents for these ideas and I've looked at over a hundred by now.
Not that people should stop tinkering, but given the legal fuel efficiency requirements (aka burn people not fuel) plus legal limits on pollution control, plus "consumer protection" laws that make it virtually impossible for a small manufacture to break into the auto market, the odds of a small company coming up with something that can beat all the parameters of standard IC engine in a mass produce vehicle today are virtually zero.
Given the inherent tradeoffs, a military engine is about the best we could hope for.
Its actually being primarily designed for use in the new SOCAM exoskeleton suits being implemented in 2018.
+Shannon Love
That was the most informative RUclips comment I've read in years. Thanks.
+Shannon Love
That was the most informative RUclips comment I've read in years. Thanks.
Liquid Piston is not trying to replace the automobile engine, at least not yet. They will work their way up to large scale manufacturing by putting this engine in all kinds of small applications. Drones, power tools, motorcycles, etc.
Nice, but it have some problems encountered on Wankel engines. Lubrication is a problem. Fuel comsumption is higher than Otto engines, but I think can be near than two-stroke engines comsumption.
All rotary engines have same common problems.
1- They are conceptualized in 2d and extruded to 3d, that is not Correct. A Sphere is NOT a extruded circle.
2- Seals run on areas that explode. After 50,000 miles carbon damage the chanbers.
That does not happen in piston engines.
Cheers, Ivan Castilla
Neah, DOA concept for anything that requires cost efficiency, usability and reliability in one package. Wear and tear will make this engine short lasting. But still, in mass production this will be perfect for cheap disposable military drones or torpedo motors where engine is although tiny and can deliver tons of power but not expected to work once fuel in the tank is used up. Which means that the market for this engine is limited to military applications, so the life of the company will depend on military contracts. Who else would need an engine that can deliver tons of power but only for a few days? What's the hype?
they have adressed the issue of uneven heating of the casing tho
lets see what r&d does before poo pooing the motor
The mixing of the exhaust with engine cooling is interesting. Won't this make it impractical to add turbo chargers?
If their claims hold true, it should have very low exhaust pressure. Superchargers could still be used.
Tiene que tener un rozamiento brutal esa pieza que encaja cada tercio de vuelta...
One of the big problems with a wankel rotoary is that there is a large temperature differential from the exhaust to the intake parts of the chamber, which makes sealing the engine troublesome. This engine seems to avoid that issue. It's an interesting idea to put the apex-seals on the inside of the housing, and not on the rotor. How does the power:weight ratio compare with a regular 2-stroke?
Novel idea, geometry seems to be similar but inverse to a traditional rotary. Noticed the slots for the "apex" seals in the housing and not on the rotor. Only mechanical issue I can potentially see is when you want to run 2 or more on the same eccentric shaft. The divider plates would have to have the inlet and exhaust galleries imbedded.
Yes, this is one of the many related geometries examined by Felix Wankel in the 1920's, all based on a circle rolling around inside or outside of another circle.
combustion chamber _extreme_ wedge-geometry: the curse of dozens of rotary designs.
+tubeist- dan I know that Wankel's biggest issue was just that.
The seals...
Put the version of this into a vehicle and efficiency would be outstanding
looks like a great motorcycle engine!
this is essentially an inside out rotory
Few questions here....
1. Will the heat coming out the hot exhaust gases of rotor burn up the intake gases?
2. Can second rotor running in opposite direction eliminates the use of counter weight, creating more power similar to renesis engine of mazda.
3. When is the Diesel engine expected to be in final phase of testing.
4. Any licensing model for manufacturing them.
This isn't the great break through the companies PR dept would like us to think but I must defend it on a few points.
1) It overcomes the critical weakness of the wankel engine, the heat stress caused by having the detonation occur on only one side on side quarter of the engine block. Eventually, that causes the block to crack as Mazada found out in the 70s.
2) It's sealing issues are fair less than an Wrankel engine because the sealing occurs on the the side flat side of the rotots instead of the rotor's tips. That doesn't mean it burns less oil than modern IC though, just less than a Wrankel.
3) Someone said below that that DARPA is looking at it as a flight drone engine and in that role it might have some advantages. Firstly, it looks to be cooled by exhaust and ambient air flow, big advantage in air craft engines. Secondly, it will be a low vibration engine just like all rotary engines, important on platforms with hi-re, long distant, cameras (an maybe lasers?). Thirdly, the engine is mechanically simply, harkens back to the old radial engine that could still have some power after being riddled with bullets. Fourthly, no microchip electronics needed for high performance, important in an era of non-nuke EMP guns.
4) Hope it pans out but I grew up in the mythical "energy crisis" and have been watching supposed "revolutionary" tech appear to great fan fair, only to mysterious vanish from public site. After a little a digging, you find all these new IC engine end up as the water or hydraulic pumps that probably inspired them, but with modern improvements in tolerance of manufacturing that make them far more efficient than their Victoria originals.
Many people have already seen the Spinning Doritos.
Now, get ready for spinning Pringles!!
Bringing the rotor back baby
They say that with this they can build a 1.4kg 3.7 kW engine. And that generally can be 30-50% smaller than other engines. That is kind of nice.
How is that supposed to be expansion to near atmospheric pressure ? Same stroke as intake, right ? The seal problem may be solved but now you have crossflow admission so heated intake charge, and still a very, very hot rotor with exhaust going through seals.
Literally just a wankel with the rotor and chamber shape switched. The expansion ratio is interesting, but the question remains: How does this overcome ANY of the Wankel's issues?
Thanks! All looks as a great concept and design beyond Wankel Engine.
What is the current status of this engine, and what about proven efficiency, compared to classic diesel and petrol engines? 👌👍