Split-cycle engine now more efficient than traditional combustion engine (w/ Video)

Jan 24, 2011 by Lin Edwards report
Engine Prototype. Image: Scuderi Group

(PhysOrg.com) -- Split-cycle engines have been around for some time but until now have never matched the fuel efficiency of traditional internal combustion engines. That is about to change, with the latest split-cycle engines from the Scuderi Group offering greater fuel efficiency and up to 80 percent reduction in NOx emissions and 50 percent reduction in CO2.

Split-cycle engines feature paired cylinders, so a four-cylinder engine has two sets of paired cylinders working together, with a crossover passage linking the two cylinders in each pair to each other. The four strokes of the engine are split into two groups, with the left cylinder handling intake and compression and the second handling combustion and exhaust. The Scuderi™ Air-Hybrid design adds an air storage tank and controls that allow it to recapture and store the energy lost as the engine operates.

The new design solves some of the problems that have hampered previous split-cycle designs. The low volume breathing problem is solved by outward-opening pneumatic valves and a reduction in the clearance between the piston and cylinder head to under 1 mm, which means virtually 100 percent of the compressed air is pushed out of the cylinder.

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Video: Scuderi Group

The thermal efficiency problem of previous designs has been solved by adopting After Top Dead Center (ATDC) firing, which avoids losses caused by recompressing the gas. Firing ATDC is achieved by high pressure air entering the cylinder and resulting in massive turbulence. Firing ATDC is a cleaner burn that also dramatically reduces NOx emissions and improves .

The Southwest Research Institute (SwRI) has been testing a 1-liter, two-cylinder engine for almost a year. The preliminary results suggest a 30-36 percent increase in fuel efficiency for the naturally aspirated Scuderi™ Air-Hybrid and a 25 percent increase for the base model. The test engine generates 135 horsepower at 6,000 RPM, which is similar to results of bigger and more fuel-hungry cars.

Split Cycle Engine. Image: Scuderi Group

Scuderi president Sal Scuderi, son of the inventor Carmelo Scuderi who died in 2002, said he expected efficiencies should improve still further as the designs are fine-tuned and new simulations are run with the engines in different vehicles.

The Scuderi can be built using conventional parts and minimal re-tooling is necessary, which makes it easier for manufacturers to adopt it. Scuderi says the technology should be licensed and on the road within three years.

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Video: Scuderi Group

The US government is introducing fuel economy rules to force manufacturers to produce more fuel-efficient vehicles, and this may make the adoption of alternatives such as the Scuderi engines more attractive.

Explore further: Circuits on demand: Engineer prints electrical components on paper

More information: www.scuderigroup.com/our-engines/

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User comments : 20

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frajo
4.6 / 5 (11) Jan 24, 2011
Awesome. Much like turbo technology.
However, a prototype is more relevant than an animation.
Why don't you just use translate.google.com?
yoatmon
5 / 5 (3) Jan 24, 2011
The functionality, efficiency, reliability and simplicity of an e-motor remains unreached and unchallenged with this complex stone age innovation.
zslewis91
5 / 5 (1) Jan 24, 2011
@yoatmon, agreed...and if they'd only learn..
TAz00
not rated yet Jan 24, 2011
The functionality, efficiency, reliability and simplicity of an e-motor remains unreached and unchallenged with this complex stone age innovation.


So use this for charging the batteries in a hybrid
krundoloss
not rated yet Jan 24, 2011
I am really perplexed as to why we dont use a Hybrid setup, with a small engine running at low RPM that constantly charges batteries for a Larger, powerful Electric Motor. Like a hydrid, but make the Electric Motor the only Driving engine, with the generator keeping the power going. Wouldnt that be the best of both worlds? I am tempted to get a cheap generator and try to make one myself!
yoatmon
not rated yet Jan 24, 2011
@ krundoloss.
The ideal hybrid would be a combination of a fuel cell and battery but alas, both are so damn expensive; a FC even more so.
david_42
not rated yet Jan 24, 2011
krundoloss - That is exactly what BMW is doing for their hybrids; a one liter diesel engine combined with two large electric motors (one per axle) and a modest battery. They are projecting 80+ mpg for a mid-sized sports car.

yoatmon - fuel cells using what? Hydrogen is and will remain very energy-intensive to manufacture and no other fuel cell technology has been demonstrated at the power levels required.
ForFreeMinds
1 / 5 (7) Jan 24, 2011
Nice progress on efficiency - it looks good.

On the other hand, I don't like that "the US government is introducing fuel economy rules to force manufacturers to produce more fuel-efficient vehicles." Government will then pick winners and losers and create opportunities for government theft.
PPihkala
3 / 5 (2) Jan 24, 2011
I am really perplexed as to why we dont use a Hybrid setup, with a small engine running at low RPM that constantly charges batteries for a Larger, powerful Electric Motor.

I think Chevy Volt works like this, using atkinson cycle engine to spin the charger. Of course it can use only battery power when that is sufficient.
Glyndwr
5 / 5 (3) Jan 24, 2011
Awesome. Much like turbo technology.
However, a prototype is more relevant than an animation.
Why don't you just use translate.google.com?


why dont you ;)

to be fair english lingual dominance has an air of arrogance. And I am first language english...its not even the most efficient language
bugmenot23
not rated yet Jan 25, 2011
Ferdinand Porsche pioneered diesel engines powering electric motors well before WWII to eliminate transmission difficulties. Adding a battery to this cycle for power storage and filtration (capacitance) was *very likely* tried (and if not by Porsche probably by a fellow German) shortly thereafter and found to be impractical given battery technology.
yoatmon
not rated yet Jan 25, 2011
@ krundoloss:
Of course hydrogen; what else?
"The catalyst operates at 100 mA/cm2 at 76% efficiency." Add http:// in front of web address.
web.mit.edu/chemistry/dgn/www/research/solar.shtml
deatopmg
2 / 5 (4) Jan 25, 2011
@ yoatmon
After you add in H2 generation efficiency (ca. 70%), coupled w/electric generation efficiencies (ca. 35%), transmission losses (ca. 5%) compression losses, and misc other system losses, one is better off w/ a direct injected Diesel and far better off w/ a DI turboDiesel (thermal efficiency 45 - 50%).

Most of these posts are clearly from non-engineers or very young ones. People much smarter than you or I have been looking at how best to improve the efficiency of the existing vehicle power plants and they have been doing this for many generations. Scuderi is just one example. Results so far - the hybrids, whose cost to the environment for full life cycle is about 50% more than a gasoline powered car, same basis. But owning a hybrid or electric car allows the owners believe they are superior. Such self delusion, just amazing.

Remember in every scheme or fantasy; There is no free lunch! You are limited by the laws of nature and what people are willing to pay.
yoatmon
not rated yet Jan 26, 2011
@ deatopmg:
Of course, it's so damn convenient to just keep on polluting the environment. Why don't you wake up and stop dreaming and start thinking.
yoatmon
not rated yet Jan 26, 2011
(http://)newscenter.lbl.gov/news-releases/2010/07/29/graphene-under-strain/
Tedvetteman
not rated yet Jan 26, 2011
The split cycle sounds good from an energy efficiency perspective, but what is the weight penalty? Diesels are heavy by nature and this one adds a lot of components to what amounts to a reciprocating-supercharged diesel. Anyone have info on power to weight?
PinkElephant
not rated yet Jan 26, 2011
@deatopmg,
the hybrids, whose cost to the environment for full life cycle is about 50% more than a gasoline powered car
What a load of crap. Though I suppose it *might* be true, in a fictional world that hasn't yet stumbled upon the miracle of recycling...
But owning a hybrid or electric car allows the owners believe they are superior. Such self delusion, just amazing.
What you've stated is actually the common delusion of non-hybrid owners regarding hybrid owners. If you truly believe that buying a hybrid is all about feeling superior (rather than just being a techno-geek and/or early-adopter), then evidently you've been had and successfully programmed by fossil energy and traditional car marketeers yet again. Don't you ever get tired of being played?
tarheelchief
not rated yet Feb 01, 2011
I am frankly surprised how the Steyr Company has held off the imitators in South America,Asia,the US,and the EU. One would think they would cede their licenses to Ford,GM, Toyota,Honda,Hyundai,or a Middle Eastern nation.
Magnette
not rated yet Feb 02, 2011
] But owning a hybrid or electric car allows the owners believe they are superior. Such self delusion, just amazing.
What you've stated is actually the common delusion of non-hybrid owners regarding hybrid owners. If you truly believe that buying a hybrid is all about feeling superior (rather than just being a techno-geek and/or early-adopter), then evidently you've been had and successfully programmed by fossil energy and traditional car marketeers yet again. Don't you ever get tired of being played?

Exactly the same could be said of hybrid owners as well as there's certainly a game being played....for example I drive a hybrid for work, purchased by my boss. Unfortunately it uses a 5.0 litre V8 to charge the batteries and averages 23mpg even when being driven as carefully as possible...and the emissions aren't that great either. Basically he fell for the hype of Lexus and bought a LS 600hL. They played the 'green' card and he fell for it, well done them!
PinkElephant
not rated yet Feb 03, 2011
@Magnette,

I'd say anyone who buys a Lexus as a company car, isn't exactly being driven by utilitarian concerns in the first place. Granted that same Lexus in a non-hybrid configuration, probably has even worse mileage and emissions. But regardless, buying a luxury brand means image matters more than practicality in any and every sense.

No, when people like deatopmg bash hybrids, they're specifically targeting the likes of Toyota Prius and Honda Insight. In the case of these cars, the distinctive shape is dictated by aerodynamics (with the goal of minimizing the drag coefficient), and the overall design of both drivetrain and chassis aims to maximize fuel efficiency in every aspect.

These cars are at the leading edge of consumer-grade automotive technology. Like with everything else, one pays a premium for being an early adopter. But it's the early adopters who pave the way to mass-production, and subsequent availability and affordability for all.

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