Laser Ignition May Replace the Spark Plug 388
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."
So what happens (Score:5, Interesting)
In most likeliness (Score:4, Interesting)
Don't think fax machine, think FD Trinitron.
Re:So what happens (Score:5, Interesting)
I don't doubt that they'll work it out in the end, engineers have a long history of being clever like that; but it is going to take a giant pile of tweaks on top of the naive implementation.
Has other applications (Score:3, Interesting)
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.
Re:So what happens (Score:4, Interesting)
Exactly.
What is the point?
Obscure claims of increased fuel efficiency and reduced emissions, based on what? A spark is a better combustion source than a laser.
This looks like a solution in search of a problem if you ask me.
Re:So what happens (Score:3, Interesting)
I'd be pretty impressed if they can make high energy fibre optics work for any length of time in a consumer auto.
My money is on the 'free air' optics. In reality, the optical paths and components could be enclosed in some sort of housing. This has been done for spark ignition in a few cars already. The ignition system is one module that sits on top of the spark plugs. In the optical equivalent, the lasers, mirrors and distributor function would be contained in an 'ignition rail', eliminating fiber optic losses and alignment issues.
Re:In most likeliness (Score:2, Interesting)
Another example of an improvement arriving to a technology just as it was obsoleted is the gas mantle, which improved the efficiency of gas lamps just about the time the electric light bulb came along.
Self Cleaning (Score:3, Interesting)
I would think it would be self cleaning, wouldn't the laser keep all the crap burned off of the lens ?
Lifetime? (Score:4, Interesting)
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.)
Re:So what happens (Score:4, Interesting)
Gasoline? Internal combustion engines? They are terribly wasteful of both fuel, and energy. Even a very efficient gas burning engine pumps fuel out the tail pipe, which is the reason catalytic converters are required on vehicles in the US. If a laser can set off a more thorough, more efficient ignition, that burns ALL of the gasoline in the cylinder, fuel mileage will increase, for certain.
Modern gasoline engines already burn something like 95%+ of the fuel that is pumped in so there really isn't that much room for improvement. I suppose any improvement is better than none at all but don't expect any miracles. FWIW this is one of the reasons those gasoline additives that claim to improve efficiency are mostly BS, even if they did cause the fuel to burn 100% it would be hard to even measure the difference in mpg.
Re:Great... (Score:4, Interesting)
That's why I'm putting an open source engine management system in mine:
http://en.wikipedia.org/wiki/MegaSquirt [wikipedia.org]
Re:So what happens (Score:5, Interesting)
When it comes to ignition, compression is never a problem these days. What compression does do is increase *heat*. So unless your running gasoline with a higher octane rating, you will get detonation and pre-ignition the higher your compression ration is. ....and what happens when you use a laser to ignite a large portion of the fuel/air mixture at once, rather than using a spark plug to ignite a small flame kernel and waiting for it to propagate? The fuel mixture burns much more rapidly, allowing you to run less ignition advance. The result is more power, fewer emissions, and the engine is LESS prone to detonation. So then you can jack up the compression ratio and gain even more power.
Dependable (Score:3, Interesting)
Re:Lifetime? (Score:3, Interesting)
I'm guessing that's why they mention fiber optics in the summary, to pipe it in from a cold area (e.g. under the dash) and through the firewall.
So close... (Score:3, Interesting)
>> "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,
Smokey Yunick's adiabatic engine (Score:2, Interesting)
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.
Why not use microwaves? (Score:4, Interesting)
Re:bs science as usual- and a waste of time/effort (Score:3, Interesting)
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.
Comment removed (Score:3, Interesting)
Re:So what happens (Score:3, Interesting)
I remember in the early days when they went to electronic ignition the spark plug wires couldn't take it either and would fail quickly - they'd get brittle, crack, and lose the ability to conduct. After a while, spark plug wires got better; I don't know anyone who actually replaces them unless it's a high-mileage vehicle (like my 1989 Trooper, about due for another set at 224K miles....)
As you say, the engineers will work this out, but not before some pain....
Re:So what happens (Score:3, Interesting)
Wow, someone needs a reality check. Diesel in most places is comparable to gasoline and has a higher energy density than gasoline. Add in the extra fuel efficiency and the cost in cents per mile for diesel whips the pants off gasoline. The smoke you refer to was from high sulfur diesel which is no longer sold in the United States. Diesel has been shown to release less emissions than gasoline, and in fact VW is trying to reverse myths that you have with ad campaigns like this http://tdi.vw.com/a-coffee-filter-shows-how-clean-tdi-clean-diesel-is/ [vw.com].
And the new Turbodiesels get much better mileage than their equivalent gasoline counterparts. For example the Jetta gasoline vs diesel goes from 20 to 29 city and 29 to 40 highway (45% city, 38% highway). For comparison, the Honda Civic gasoline vs hybrid goes from 25 to 40 city and 36 to 45 highway (60% city, but 25% highway). Also note that the VW Jetta TDI won the 2009 Green Car of the Year award.
And there is no way in hell a hybrid beats a diesel in performance. The Civic Hybrid has 110 HP/123 ft-lb of torque. The Jetta TDI? 140 HP/236 ft-lb of torque. There is a reason diesels have been winning the Le Mans.
Re:Great... (Score:3, Interesting)
Anyway. He loves it and thinks it's the coolest thing ever.