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Laser Ignition May Replace the Spark Plug
dusty writes "Laser Focus World has a story on researchers from Ford, GSI, and The University of Liverpool and their success in using near-infrared lasers instead of spark plugs in automobile engines. The laser pulses are delivered to the combustion chamber one of two ways. One, the laser energy is transmitted through free space and into an optical plug. Two, the other more challenging method uses fiber optics. Attempts so far to put the second method into play have met some challenges. The researchers are confident that the fiber-optic laser cables' technical challenges (such as a 20% parasitic loss, and vibration issues) will soon be overcome. Both delivery schemes drastically reduce harmful emissions and increase performance over the use of spark plugs. So the spark plug could soon join the fax machine in the pantheon of antiquated technologies that will never completely disappear. The news release from The University of Liverpool has pictures of the freakin' internal combustion lasers."
When the vehicle gets to be a few years old, and the rings start letting extra oil past. Soon the lenses are covered with soot. Sparks can still jump through a moderate layer of soot, can the laser?
This will probably arrive as a viable and reliable technology right about the same time the internal combustion engine is on it's way out.
Don't think fax machine, think FD Trinitron.
Dedicated Cthulhu Cultist since 4523 BC.
There's another obvious application for this - detonating nuclear bombs.
Nuclear weapons require that all the charges be detonated simultaneously, within nanoseconds, so that the implosion squeeze is precisely symmetrical. (OK, A-bomb geeks, I'm ignoring asymmetrical designs and flying-plate systems here.) If the timing is even a few nanoseconds off, the core won't be compressed; it will just blow out on one side, and a "fizzle" yield will result.
The usual trick for this is to use an "exploding wire" detonator. Unlike regular detonators, which have an intermediate explosive to start the main explosive, exploding wire detonators do it in one step, by discharging a capacitor bank through a resistance buried in the explosive. This takes a very fast high-voltage high-current switch, and the traditional solution is a krytron, a gas-discharge vacuum tube from the thyatron family. There have been big flaps over the years about various countries trying to acquire krytrons, which aren't classified but are export-controlled.
Krytrons are 1940s technology. This laser ignition system could be its replacement. One big laser pulse pumped through fibers of equal length to each detonation point should do the job. And it's off the shelf dual-use technology.
> Soon the lenses are covered with soot.
I would think it would be self cleaning, wouldn't the laser keep all the crap burned off of the lens ?
We are Dead Stars looking back Up at the Sky
The problem with putting lasers in your engine is that it gets hot in there, and laser lifetime plunges drastically when you run them at elevated temperatures. I'm sure the dealers will love us having to replace our laser-plugs every two months, but no one else will.
(And if you're thinking thermo-electric cooling is the answer, that's going to use a whole lot of juice; don't know how feasible it is.)
That's why I'm putting an open source engine management system in mine:
http://en.wikipedia.org/wiki/MegaSquirt
Hopefully they are dependable. With the heat of engines I'm not sure how long they would last. One good thing is that it'll flood the market with cheap high power lasers. Importing the parts my have to go by the FDA since they regulate lasers.
*It's not what you can do for the Dark Side but what the Dark Side can do for you!*
>> "So the spark plug could soon join the fax machine in the pantheon of antiquated technologies that will never completely disappear."
Aw, you were so close, but missed the mark. There are many other examples that you could have used and kept with the car theme. For instance,
Carol vs. Ghost
http://www.eng-tips.com/viewthread.cfm?qid=78116&page=1
FTL
For those of you not in the know, Smokey Yunick was a legendary race car mechanic and Popular Science correspondant. He died a couple of years ago. In March 1983 Popular Science carried a story about an engine he had developed that only had two cylinders and 78 cubic inches but developed 150 hp and got 60 mpg when installed in what looks like a Volkswagon Rabbit. He called it his "adiabatic engine." Supposedly all sorts of car companies were quite interested in the engine.
When I see this I will belive the oil companies have given up.
There's probably a good reason, but why not use microwaves? Wouldn't that be better to ensure even burn?
I've spent entirely too much time under the hood of a car(21 year auto mechanic), and you are entirely incorrect.
Degrading plug wires either cause a misfire, which is blindingly obvious and kills mileage horribly, or doesn't. There is no middle ground.
You are 100% full of shit.
I have personally had intermittent shorts in spark plug wires which caused them to fire fine sometimes. I found the problem by flexing the wire in question while testing it and watching the resistance go from a few kOhms to infinite.
In addition, plug wires can go partly bad, to the point where the resistance will be increased, causing a weak spark on some wires. You can find this problem by laying out all the wires on a table and checking their resistance. Longer wires should have more resistance. If you find a discrepancy, you've got at least one bad wire. Furthermore, in a vehicle with a flaky electrical system (say, one out of three alt. coils is bad) your voltage can be highly RPM-dependent, so you can have good spark only at high RPM.
Modern electronic ignition systems are fairly immune to spark plug wear until extreme circumstances, such as missing three tuneups in a row with standard plugs. Then you will sometimes get drivibility issues and lose 1mpg, tops.
This has relatively little to do with the ignition system and everything to do with the rest of the engine. Since it's computer controlled, the computer tries to prevent you from doing things with your engine that your plugs can't cover (it learns what causes misfires.) The biggest difference there is really that most modern ignition systems have a higher voltage; in the 1960s you might have 20kV, now it's usually more like 80. But you could get a high-performance coil back then; you'd just burn out your points, which we don't have any more.
I would be ASE certified in automotive electronics if I could have afforded the exam back in the day. I am ASE certified in heating/cooling/air-cond. You have just told people things that aren't true, and no amount of experience excuses this.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
In case anyone is wondering about real-world performance of megasquirt (which has always sounded to me like a bad porn movie title) my ex-boss built a megasquirt system for his 1985 Jeep. It took him over a year to get it working because he had a lot of problems getting the new mass air flow sensor to accurately measure the airflow (positioning it was fairly critical) but once he managed that, the system works beautifully. He's been using it for 5 years, including several cross-country drives and a lot of very serious offroading. He comes back from trips with the roof of his jeep bashed in -- that kind of offroading. It's given him better than 10% improvement on fuel economy, a little more power (hard to measure) and vastly better reliability, particularly in rough offroad conditions. Anyone who has ever done serious offroading in a stock carbureted '70's or '80's jeep knows about how poorly they can perform when the float starts sticking and the engine starts going into fuel starvation.
Anyway. He loves it and thinks it's the coolest thing ever.
Nostalgia's not what it used to be.