Ultra-Efficient Gas Engine Passes Test

MIT Technology Review ^ | March 08, 2010 | Kevin Bullis

[epithermal]

Transonic Combustion, a startup based in Camarillo, CA, has developed a fuel-injection system it says can improve the efficiency of gasoline engines by more than 50 percent. A test vehicle equipped with the technology gets 64 miles per gallon in highway driving, which is far better than more costly gas-electric hybrids, such as the Prius, which gets 48 miles per gallon on the highway.

[epithermal]

This seems to be a serious technology. Anyone know if this is hype or not?

[Army Air Corps]

Ultrasonic fuel injectors?

[verity]

"If it works as promised , the new technology would improve fuel economy by far more than these other options, some of which can improve efficiency on the order of 20 percent. It is expected to cost about as much as high-end fuel injection systems currently on the market, Rocke says."

I wonder how large the IF is?

[highlander_UW]

I’m not an engineer, but this looks FAR cheaper than the cost of hybrid battery/gas cars and ultimately much less polluting as well, especially given the impact of disposing of all those batteries when they die.

[Celerity]

An australian company was experimenting with this in the mid 90s. They atomized fuels using sounds, and even ionized the intake air before mixture.

A few steps away from sound-pulse based solid state valves too. But for a valvetrain, check out the US company AURA. They have also got a few R&D projects out and about in the field.

[dr_who]

Doesn’t matter if it’s hype or not. There’s always a catch.

[DainBramage]

Explains why the sound clickity clack and chitty chitty bang bang makes my truck get 14 mpg.

[wbill]

There's likely a little truth in it. Figure that cars are incredibly inefficient (even now), and there's plenty of room for improvement.

The Claim: "steady cruising speed of 50 miles per hour, the test car gets 98 miles per gallon." is a little disingenuous, though, I think. People will read "The car gets 98 mpg". I could buy that once it reaches a "cruising speed" that its mileage would be good - any car will get good mileage at a constant speed, especially under controlled conditions.

I'd like to know what the mileage is in accelerating to 50mph. And also in a stop-start environment.

[Little Pig]

Air-operated valves are already used in F1 engines, and it’s about time they arrived in road cars. Those or rotary valves can get rid of a massive amount of frictional loss inside the engine, which in turn can allow engines to be smaller and more efficient. They also allow far higher RPMs, which again allows for more responsive engines with smaller displacements.

[prisoner6]

treats the gasoline with a catalyst that "activates" it, partially oxidizing it to enhance combustion.

Pressure and heating have been done before with >some< success.

The catalyst remark makes me skeptical. And then there's the "test" vechicle. 64 mpg compared to what? What did the vehicle get BEFORE they worked their magic. A control for comparison numbers would be nice.

For now I'm sticking with my cow magnets.

prisoner6

[The Comedian]

Unless it's wind-powered, it will be outlawed by the Obama Regime.

And if it *is* wind-powered, if the tech is owned by a Republican contributor, the business will be audited and shut down.

Frowning takes 68 muscles.
Smiling takes 6.
Pulling this trigger takes 2.
I'm lazy.

[Army Air Corps]

I am also familiar with the spherical rotary valve systems of Coates Engineering. Interesting stuff.

[Fresh Wind]

I'd like to know what the mileage is in accelerating to 50mph.

And how long it takes to get there.

[Little Pig]

Valvetrain friction is the main source of horsepower loss in the engine. It’s something like 30% of the engine’s total capability. Less loss means more of that can go to driving the wheels, and therefore engines can be smaller, and thus more efficient.

[cicero2k]

There’s alot of room for efficiency improvement in IC engines so this may be plausible. On the other hand, a Prius that gets 48 MPG? Not the way Al Gore’s son drives his.

[mdmathis6]

Did they test this with 100 per cent gas or with ethanol blends?

[prisoner6]

My nearly 3 ton '98 Durango 4x4 with a 318 cu in engine, "dirty" roof and heavy brush guard on the front, gets only 9-10 mpg around town. (Where I admittedly have a heavy foot, there are lots of hills and I drive only a couple of miles to work)

On the highway "Canyonero" easily gets 22-23 mpg. Of course I set the cruise to 55-60mph, sit back and relax in the leather seats and enjoy right wing radio in air conditioned comfort, hehehehe!

Lord I love that vehicle!

prisoner6

[wbill]

On the highway "Canyonero" easily gets 22-23 mpg.

Yep, and I bet if you somehow discounted the gas it took you to get up to 55-60 (like this article did), you'd be much higher than that. :-)

Nothin' wrong with having a comfortable vehicle. I'll take my Ford Escape over a Toyota Pious, every day of the week.

[CharlesWayneCT]

First of all, if this is new technology, it’s going to cost more, so it will be just like the “more costly gas-electric hybrids” until it reaches general use.

Second of all, the inefficiency of the gas-electric hybrid is the gas engine. If you put one of these efficient gas engines in a gas-electric hybrid, it will also improve it’s gas mileage.

On the other hand, the true efficiency of the gas-electric hybrid is based on the relative efficiency of electric storage and retrieval vs gas engine variable efficiency. The gas-electric runs the gas engine at it’s peak efficiency all the time (mostly), tapping extra power to store in batteries, and using it when more power is needed.

Running the gas engine at 30% efficiency all the time, vs a standard cars average 20% efficiency, is what makes gas-electrics “more efficient”.

As you increase engine efficiency, you will reach the point where the electric battery storage retrieval losses become a deciding factor, and the gas-electric hybrid will no longer beat the gas-only propulsion.

[Zathras]

Based on what I read, the injectors could be 2-4x more expensive and the car would probably require a HP pump similar to diesels but the science seems sound.

Still it would be much cheaper than a hybrid drivetrain.

[iowamark]

Rocke says that at a steady cruising speed of 50 miles per hour, the test car gets 98 miles per gallon.

[bmwcyle]

without making vehicles more expensive. "It's a time of renaissance for internal combustion engines," says William Green, a professor of chemical engineering at MIT. Improvements include smaller engines boosted with turbocharging, improved valve timing, and direct injection,

No, it couldn't be.

[bmwcyle]

without making vehicles more expensive. "It's a time of renaissance for internal combustion engines," says William Green, a professor of chemical engineering at MIT. Improvements include smaller engines boosted with turbocharging, improved valve timing, and direct injection,

No, it couldn't be.

[count-your-change]

It sounds reasonably well thought out. One point of power loss in the typical gasoline engine is the need for a piston to compress the charge before firing. Another is achieving a uniform burn rate through out the mixture, which explains why two spark plugs per cylinder produces more power than one.

A hot compressed mixture directly injected would certainly increase mileage. Time for the road tests.

[count-your-change]

It sounds reasonably well thought out. One point of power loss in the typical gasoline engine is the need for a piston to compress the charge before firing. Another is achieving a uniform burn rate through out the mixture, which explains why two spark plugs per cylinder produces more power than one.

A hot compressed mixture directly injected would certainly increase mileage. Time for the road tests.

[PDGearhead]

A small diesel engine driving a generator that supplies electric motors on the wheels should be very effecient. This would eliminate the need for large batteries (in hybrids)and transmissions.

This is done on trains and cruise ships (and, yes they are much larger), but a constant speed diesel/generator with electric motors is a lot less complicated than hybrids.

The diesel powered VW Passat gets great mileage using a 6 speed automatic or manual transmission, so if the transmission were to be eliminated and replaced with a generator (and electric motors on the wheels), it should be even more effecient.

[BwanaNdege]

Most modern engines have little problems getting complete combustion of their fuel, which is the problem this engine appears to be addressing. Many current ordinary 4 stroke gasoline engines have such complete combustion that in some environments the exhaust is cleaner than the intake air.

The solution to more efficient internal combustion engines lies in capturing “waste” heat, that is the chemical energy in the fuel that is not converted to mechanical work but instead is lost as heat (and pressure) through the exhaust and the cooling system.

In current engines roughly 1/3 of the chemical energy is converted to mechanical work (propel the car), 1/3 lost as exhaust heat and 1/3 lost as cooling system/radiated heat.

BMW is working on a mini-turbine to capture exhaust system heat. The aircraft turbo-compound engines of the ‘40’s & ‘50’s put turbines in the exhaust stack and coupled them to the crankshaft. IIRC, the/R-3350 engines had 3 turbines, each adding about 50 shaft horsepower. Complexity & expense were their undoing.

As to the question, “is it hype?”, the comparison of “X gets 64 mpg while Y gets only 48 mpg” is almost meaningless in itself, unless the engines are in otherwise identical vehicles and test conditions. A more informative comparison would be of Brake Specific Fuel Consumption (BSFC).

A typical gasoline engine has a BSFC of 0.45 to 0.50 pounds of fuel consumed per hour per horsepower produced. (gasoline weighs about 6.2 lbs/gallon). A large marine diesel might have a BSFC of only 0.25 lbs per hour per horsepower. (Diesel fuel weighs about 7.1 lbs/gallon)

This is a large marine diesel:
http://people.bath.ac.uk/ccsshb/12cyl/

Some facts on the 14 cylinder version:
Total engine weight: 2300 tons (The crankshaft alone weighs 300 tons.)
Length: 89 feet
Height: 44 feet
Maximum power: 108,920 hp at 102 rpm
Maximum torque: 5,608,312 lb/ft at 102rpm

[urtax$@work]

replace your car engine with a farm tractor engine and
save the R&D-recoup$$ for someone else.

[biff]

F1 valves are not air operated, they use an inflatable rubber donut in place of a valve spring. Springs cannot hold up to 18,000 RPM

[Yo-Yo]

No, it couldn't be.

You're right, it couldn't be. This story isn't about mass transit.

[dfwgator]

No, it couldn't be.

Only if the engines would be used in trains.

[coon2000]

I don’t even want to know what my 2002 Silverado with a 496 cu in gets around town. Generally it gets me from gas station to gas station, but you couldn’t get me to give it up for anything. My son tells me he wants it when he gets his drivers license. I guess I’ll part with it then, so I have a couple of more years with it.

[epithermal]

Interesting. I am not an engineer, but my brother is a PhD, heat flow engineer and I like to talk to him about the subject when I can. So, I know it is all a matter of efficient use of heat. While reading about this engine I ran across an article for a waste heat recovery system here that looked interesting: Army SuperTurbocharges to the future

[Little Pig]

And so they are. Somehow I had always understood they were fully air-actuated.

[glide625]

Doesn’t matter; even if it’s true it’ll never see the light of day.

[troy McClure]

Valves? Two Strokes don't need no stinkin valves. Go Trabbi