Have you ever heard about LiquidPiston engines? Their a rotary engine but not a Wankel engine, and produce a lot of power for their size. Here is a link to their website https://www.liquidpiston.com/ Thought you mite find them interesting, if you haven't heard about them already.
Looks like another company's attempt at a rotary engine. Been done.
It's been around for about 20 years. There are hundreds of engine designs out there that never become popular (usually not feasible for practical reasons). I have not seen this one in an actual product yet.
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Like everything ... time will tell.
The question is wether there’s even a market for a rotary engine.
As it seems, as far as cars - with modern engines it’s not about size, it’s not about performance - it’s about compliance, and cost.
There’s a reason why Hyundai still uses Gamma and Kappa engine architecture,
and Honda uses the same L-series from the Jazz, with the addition of a turbo and GDi, on pretty much on all cars.
Emissions / cost - nothing else really matters all that much.
It’s just another company that builds rotaries like UEL (UAV Engines Limited) that is actually a very strong contender on that market.
So yeah, I don’t think that we’ll see a serious rotary in a production car any time soon.
I agree with you, but I think these rotaries could be used to replace other engines in vehicles such as skid-steers, small to medium excavators, backhoes, lawn mowers, and many others. Personally I found this engine very interesting, just was curious what other people thought.
I do not see any of these companies abandoning their current suppliers with proven designs to use some new design that promises improvements in areas that don't matter to them.
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Just a reminder that commercial engines are ultra conservative - Hyundai's commercial petrol engine offering is a G4FC (Gamma MPi) originally launched in 2006.
Same with pretty much any manufacturer, Volvo's Deutz engines that power most of their equipment have been originally launched in 1998 with the latest version (D13K) being introduced in 2012 - Volvo is also not interested with changing what has been proven as a reliable engine.
Same with military applications, the newest engine I found in any military truck is the PowerStroke 6.7 that was launched in 2011. Even the newest military truck on the market, the JLTV ships with a modified 6.6 DuraMax, an engine from 2001.
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Notiably, all these engines, when they do into commercial/military/equipment applications they de-rate their output severely, remove efficiency tech, and (in most cases) all tons of room around them -
so again, I do not see the appeal of a higher output smaller engines in such equipment when all that matters is cost and the design being proven reliable over time.
I think it’s a moot point. All the emphasis now is turbocharged engines, hybrids, EVs.
Today's hybrid ICE's often employ some combination of Miller or Atkinson cycle, but still using reciprocating pistons.
They looks similar. What’s the key difference between a liquid piston and the wankle?
Here's what they said on their website about the differences.
While it is a rotary engine, LiquidPiston’s X Engine is NOT a Wankel engine. It has a fundamentally different architecture and operation.
The Wankel rotary engine demonstrated excellent power to weight characteristics and exhibited low vibration even at high RPM. Despite these advantages, the Wankel was always plagued by poor fuel economy, emissions problems, and durability issues, especially in the apex / tip seals. These challenges are due to a number of inherent issues: 1) a narrow combustion chamber prevents adequate flame propagation, while also having high surface to volume ratio which cools the charge and reduces efficiency; 2) the engine is poorly sealed, leading to significant blowby, thereby decreasing efficiency; 3) the Wankel engine operates on the same conventional 4-stroke Otto cycle with spark ignition as a piston engine; however there are inherent challenges to operate > 10:1 compression ratio, and this engine was forced to compete with piston engines that had over one hundred years of prior development; and 4) the tip seals, in addition to being difficult to seal, are also difficult to lubricate; oil must be injected into the charge, with the majority of the oil burned in order to lubricate the gas seals.
The ‘X’ engine essentially “inverts” the Wankel engine. While a Wankel engine has a 3-sided triangular rotor, within a 2-lobed oval housing, the X engine has a 2-lobed oval rotor in a 3-sided housing. The X engine captures the main advantages of the Wankel, including 1) high power-to-weight ratio [a one rotor X engine behaves like a 3-cylinder 4-stroke]; 2) simplicity – having only 2 moving parts – a rotor, and a shaft; and 3) like the Wankel - the X engine is inherently balanced with no oscillating components, therefore having minimal vibration. Unlike the Wankel however, there are several key differentiators which address the bulk of the older Wankel’s design deficiencies:
The combustion chamber in the X engine is located in the stationary housing, with most of the gas displaced during compression into this stationary combustion chamber. This makes the X engine uniquely suitable for high compression ratio operation with Direct Injection and Compression Ignition (which is not possible in the Wankel without boosting or a second compression rotor). Additionally, the combustion chamber can take any geometry, and can be approximately spherical, optimized for surface to volume ratio, thereby improving combustion efficiency and reducing heat transfer.
The apex seals of the X engine are located within the stationary housing, and do not move with the rotor. The seals do not experience centrifugal forces, and can be lubricated directly by metering small amounts of oil directly to the sealing surface through the housings, which means that oil consumption can be reduced to levels potentially comparable to that of a 4-stroke piston engine (essentially negligible).
The unique sealing geometry of the X engine has 3-5 times less blowby than the Wankel rotary. This is mainly because 1) the Wankel requires clearance at the corners between its side/face seals and its apex seals, while the X engine does not; and 2) the Wankel seals traverse across holes that contain spark plug(s), whereas the X engine does not.
I'd like to get your opinion of the new liquid piston engine. Essentially it's an inside out Wankel rotary engine that addresses the main weakness of the rotary engine. To my untrained eye it looks very promising, what's your take? Thanks!!
Greg
Check it out here: https://www.liquidpiston.com/
As a practical matter since politicians worldwide are forcing car and truck manufacturers into producing electric vehicles, large-scale investment in a new type of fossil-fuel engine is simply not going to happen regardless of its merits.
what's your take?
we've had this discussion before. Please search before making new posts. Thanks.
(merging with previous topic)
