New Gasoline Engine Prototype Claims 3X Current Engine Efficiency

erfnet writes "A cool new high-efficiency gasoline engine prototype has no radiator, no pistons, no valves, no transmission, and no fluids (except for the fuel). At first glance it has a few similarities with the Wankel engine, but is more advanced. The engine is only suited for hybrid-electric vehicles, but that's okay. The efficiency they are claiming: is over 3x what today's gasoline engines produce. The developers, a team at Michigan State University, hope to have this engine on the market in the next two/three years."

Comments

Re:skeptical ...

[Anonymous Coward]

"what does THAT mean"

I believe the engine runs best at constant speed making if suited for electric generation, not powering stop & start driving.

Re:skeptical ...

[tulcod]

Well I don't know what algebra you learned, but an efficiency of 60% and outside (cold) temperature of 20 degrees celsius (293 degrees Kelvin) gives me a hot temperature of 459 degrees celsius, which is practical.

Re:Red Herring.

[gander666]

I loved my RX-7's. Damn fun car to drive, dead simple to work on, and remarkably reliable. Back then I didn't mind the oil consumption. It was more like a quart every 600 or so miles (1000kms +/-) But they were gas guzzlers. I think I use to get ~ 15MPG even when I was not driving aggressively.

Now I drive a Honda S2000, enjoy better efficiency (but not great), and have an equally exciting drive. Ah, progress

Re:skeptical ...

[pushing-robot]

I think he's using the Chambadal-Novikov efficiency, not the Carnot efficiency. C-N better models practical engines, but it's not an absolute limit.

Not a problem with hybrids, actually

[Kupfernigk]

There is no problem at all with maintaining legal highway speeds with a hybrid; the gasoline engine is designed to be able to maintain a speed on the level of over 100mph. US cars tend to be vastly over-engined because...because other cars are vastly over-engined, hence the fuel-glugging traffic light/highway merge race. The hybrid is a very logical solution to the problem of providing an engine with sufficient power for cruising, with a booster available for acceleration. After over 20 years of Diesels, I've now decided that hybrids are Good Enough for my next car. This is partly because I suspect that rising oil prices are going to force a change in driver behaviour; many of the worst drivers are probably only marginally able to afford their vehicles.

The difficulty with this thing is that it is NOT suitable (if you read the article) for a hybrid. That's because the engine is unsuited for use as the baseload prime mover. It is only suitable for a full electric transmission with battery storage. Full electric transmissions are expensive and inefficient and, as I note in another post, probably can't compete with plain old Diesel.

I've been looking at full electric transmission for my next boat design, using a constant speed generator Diesel to run a large alternator with direct drive to the motors and auxiliary battery to enable short term high power (i.e. twice the generator output for an hour.) So I have been doing the maths...and it doesn't add up. It is more efficient and cheaper to have a small Diesel prime mover topping out at 2400rpm, and an auxiliary electric motor to boost shaft speed to 3000 for short periods(owing to the cube law, both motors have the same power.) I'm just confirming what Toyota and others already found out - hybrid is the most efficient.

Re:Not a problem with hybrids, actually

[atamido]

Why bother with transmissions, crankshafts, axels, and so on? Just extra weight to haul around. Hubless eletric motors on all wheels.

The added weight makes them horribly inefficient for anything except very smooth streets. Super heavy wheels tend to be a bad thing. This concept has worked well for some things, such as city buses where the city has well paved streets.

It means...

[Pollux]

You didn't read the flippin' article.

If you had, you would have likely watched the youtube vid that explained the concept.

This engine is not an engine that directly propels a vehicle as a standard internal combustion engine does. Such engines are very inefficient, as much of the energy exerted is converted to heat, not to mention the additional energy that's used just to propel the weight of the engine itself. If there was a way to reduce the heat generated, and/or create a smaller and/or lighter engine that significantly reduces its mass, you would significantly improve energy efficiency. (Example: When engine blocks moved from cast iron to aluminum, it not only reduced the weight of the engine, but also allowed quicker transfer of heat energy out of the engine. Significant improvement of engine efficiency.)

This new engine has only one purpose: to spin a generator which charges the motor's batteries. With only that purpose in mind, this particular engine only has to run at a single speed to generate the RPM necessary to spin a generator. There's no need for lots of torque to propel the car forward at low speeds, plus one single RPM means that no drive train is necessary, plus one single RPM means that you can really simplify the design of the engine so that a minimal amount of cooling is required. All-in-all, you cut probably 90% off the weight of the engine, no longer require a radiator, and can transfer most of the energy generated directly to the generator, resulting in a much more efficient car.

A link to the actual paper:

[John Hasler]

RADIAL-FLOW WAVE ROTOR CONCEPTS, UNCONVENTIONAL DESIGNS AND APPLICATIONS

Some text to shut up the "lameness filter": No, it isn't anything like a Wankel.

Re:A link to the actual paper:

[140Mandak262Jamuna]

It is basically a gas turbine engine. There is a centrifugal compressor. Followed by combustion chamber. Then a centrifugal turbine. Like a typical gas turbine the exhaust gases turn the turbine the is on the same shaft as a compressor. The compressor compresses the incoming air. The innovative thing is that the combustion chamber is made very compact and turned radially inward. Now a days gas turbines and jet engines use axial compressor making them long. And the combustion chamber is also arranged as long cylindrical cans along the axis. Here everything is radial. Compressor and turbine are centrifugal the chamber is radially inward.

The gas turbine takes in air continuously and produces smooth power. This one has some kind of of ring that closes incoming air. Once it is spun and if the inlet is closed it is going to create very interesting airflow, and that is some how harnessed into self ignite the fuel air mixture. It will probably have a very narrow range of operating rpm. Starting would require us to spin this up to the operating rpm before it would produce power. So forget about low end torque or any such thing. It will produce power only at one speed and at one rate. In a gas turbine you could indirectly control speed/power by controlling the fuel flow rate. This one might not work at any other rpm or even fuel flow rate. Run it, charge the batteries and shut off, is going to be the mode of operation.

So the efficiency is not going to be three fold increase. That claim comes by including the gains made by reducing the engine + transmission weight. But there is going to be electric motors and batteries added. So the claims are a little over stated. On the other hand it does not depend on any intricate seals like Wankel engines or other unknown things. Gas turbines are well known since WW II. So it is a good promising technology, but it is not likely to be any better than many other unusual engines people are fiddling with. A better picture: http://green.autoblog.com/2011/04/08/wave-disk-generator-engine-wave-of-future-video/

Re:Fuel engines and taxation

[mvdwege]

In countries where automotive development is not stuck in the Fifties, diesel car engines start up without 'massive clouds of black soot'.

Mart