Liquidpiston not dead
- Thread starter berridos
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wanttobuild
Well-Known Member
Dead men dreaming. The big guys are gonna take his idea, eliminate most of the batteries in electric vehicles. They lack the big checking account. This engine can power a generator to charge batteries. I wish them all the best though
Bill-Higdon
Well-Known Member
Ried
Active Member
My guess they need 5-10 years to get this to a commercial product if it's really a viable product.
It's just my opinion but from my experience anything less than a straight shot in to the combustion chamber limits the volumetric efficiency (VE) and therefore the power available, due to inward flow disruption (Drag), trying to get through a convoluted passageway. Naturally Turbo or Supercharger would benefit here.
It's much like the Mazda Rotary, with some possible improvements with lubricated seals in the Housings. That's why the peripheral Ports in the Mazda Rotary, will provide up to 30% increase in VE.
Don't get we wrong, I do like it and I'm no expert either, but could be difficult to get into production with everything going Electric
George
It's much like the Mazda Rotary, with some possible improvements with lubricated seals in the Housings. That's why the peripheral Ports in the Mazda Rotary, will provide up to 30% increase in VE.
Don't get we wrong, I do like it and I'm no expert either, but could be difficult to get into production with everything going Electric
George
Ried
Active Member
What I recall from my 20th century Combustion Engineering class it that the PV diagram should show small pressure offsets for intake and exhaust gas flow pressure losses. This is why dedicated gear heads will go to the trouble of porting intake and exhaust headers. Turbocharging, supercharging, tuned pies, etc., add different pressure/volume points to the PV diagram that affect overall bmep and efficiency.It's just my opinion but from my experience anything less than a straight shot in to the combustion chamber limits the volumetric efficiency (VE) and therefore the power available, due to inward flow disruption (Drag), trying to get through a convoluted passageway. Naturally Turbo or Supercharger would benefit here.
It's much like the Mazda Rotary, with some possible improvements with lubricated seals in the Housings. That's why the peripheral Ports in the Mazda Rotary, will provide up to 30% increase in VE.
Don't get we wrong, I do like it and I'm no expert either, but could be difficult to get into production with everything going Electric
George
pfarber
Well-Known Member
What part of 'suck, squeeze, bang, blow' has be revolutionized?
Other than being able to burn jet fuel/diesel its basically three wankels on one rotor. Then never speak to emissions, which was a big problem for the wankle.
No torque numbers?
I like the small and lightweight part. But emissions and (what I believe) will be low torque will be an issue.
Other than being able to burn jet fuel/diesel its basically three wankels on one rotor. Then never speak to emissions, which was a big problem for the wankle.
No torque numbers?
I like the small and lightweight part. But emissions and (what I believe) will be low torque will be an issue.
pfarber
Well-Known Member
Seeing that the 'moment arm' of the crank to the combustion 'oval' is mere inches (1inch??), and even then tangential to the crankshaft, all you have left is spinning mass and again, not very much.
Its RPM range is not super high (motorcycles rev up to 12000rpm to make any real power). Remember, the torque formula is T = F * r * sin(theta)
r and theta being what I see as lacking
Since most of the ideas are pretty steady RPM installations (generators, drones, pumps) it may have a pretty narrow band that it likes.
Since they are concentrating on 'less than 100hp' I think that may be the limit. Theoretically it *could* scale. If they have a motor that can put out diesel torque values then they win... everything.
I hope it works, but I got a little nausea reading their web site... so many words, so little information.
Looks like they just picked up a nice little Air Force contract:
www.aviationtoday.com
finance.yahoo.com
Air Force Looks to Hybrid Electric Solution for eVTOL and UAS Energy Concerns - Aviation Today
The Air Force is investing in LiquidPiston’s X-Engine technology to create a hybrid-electric propulsion system to power emerging technologies like unmanned aircraft systems (UAS) and orbs, the company announced on March 4. The Small Business Technology Transfer (STTR) contract worth $150,000...
www.aviationtoday.com
LiquidPiston Adapting Its X-Engine Technology for United States Air Force UAS and Orbs
LiquidPiston recently received a Small Business Technology Transfer (STTR) contract from the United States Air Force to adapt its X-Engine technology for UAS an
insideunmannedsystems.com
LiquidPiston Wins Air Force Contract To Overcome Shortcomings Of Batteries in eVTOL and UAS Propulsion
LiquidPiston's X-Engine is being evaluated as an enabling technology to power the UAS or orb through a hybrid-electric propulsion system.
LiquidPiston Wins Air Force Contract To Overcome Shortcomings Of Batteries in eVTOL and UAS Propulsion
LiquidPiston's X-Engine is being evaluated as an enabling technology to power the UAS or orb through a hybrid-electric propulsion system.
www.businesswire.com
pfarber
Well-Known Member
UAS and eVTOLs are being developed with battery-powered propulsion systems which have limited their range of flight. The X-Engine technology would use fuel to power a generator and charge the aircraft’s batteries extending its flight time and range, according to the company.
Sounds like the AirForce is just throwing money at something to see how bad it will fail. Why carry a battery AND gas AND an engine AND a generator? Seems like dumping the battery for more gas is a better answer.
Sounds like the AirForce is just throwing money at something to see how bad it will fail. Why carry a battery AND gas AND an engine AND a generator? Seems like dumping the battery for more gas is a better answer.
Sockmonkey
Well-Known Member
Heck, they should just buy engines from the model airplane guys. They have everything from radials to gas turbines.
PMD
Well-Known Member
I would not write this technology off for small engines. And, YES, dumping all of the electric BS from drones and replacing with more mature/proven "liquid piston" running on diesel or liquid hydrogen (yes, the technology exists and is proven) is what WILL happen (with something like 50:1 difference in energy storage density). The kick with this engine is inability to stack "rotors", so single plane (excuse the pun) is limiting factor.
Sockmonkey
Well-Known Member
This is essentially a rotary version of the Scuderi cycle yes?
It's a neat concept, but there's some issues and a few unanswered questions I noticed.
The intake air temperature must be crazy high with the exhaust gases surrounding the intake tube.
They mention cooling air mixing in the exhaust, but they don't mention where it comes from, there's no obvious intake for it, and if it's not pressurized, the exhaust will blow out the cooling intake.
If it does have forced induction to generate the pressure, then the 4hp power output isn't that impressive, since they didn't include the weight of the turbo/supercharger. Turbo requires hot exhaust, so that seems out, and supercharger draws power directly.
Air and fuel are apparently mixed outside the engine (not really explained how), which is why it can run different fuels, so that is no different than a piston engine. This doesn't apply to diesel, but you'd need to fit the injector for it on this engine anyway.
The video mentions the Wankel's apex seals as being a problem, but ignores that this engine also has apex seals too, they're just in the block instead of rotor. From a wear perspective, I don't think there's much difference there.
Don't get me wrong, I hope they're successful and get this to market. They do have a working prototype, and that's a big step forward. I just wonder about the issues they glossed over or never explained.
The intake air temperature must be crazy high with the exhaust gases surrounding the intake tube.
They mention cooling air mixing in the exhaust, but they don't mention where it comes from, there's no obvious intake for it, and if it's not pressurized, the exhaust will blow out the cooling intake.
If it does have forced induction to generate the pressure, then the 4hp power output isn't that impressive, since they didn't include the weight of the turbo/supercharger. Turbo requires hot exhaust, so that seems out, and supercharger draws power directly.
Air and fuel are apparently mixed outside the engine (not really explained how), which is why it can run different fuels, so that is no different than a piston engine. This doesn't apply to diesel, but you'd need to fit the injector for it on this engine anyway.
The video mentions the Wankel's apex seals as being a problem, but ignores that this engine also has apex seals too, they're just in the block instead of rotor. From a wear perspective, I don't think there's much difference there.
Don't get me wrong, I hope they're successful and get this to market. They do have a working prototype, and that's a big step forward. I just wonder about the issues they glossed over or never explained.
