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."
Re:Stupid question (Score:4, Informative)
Gasoline will auto-ignite just fine, it's just much trickier to control when it ignites than with spark ignition or diesel ignition.
Mercades has a engine in development called the diesotto [telegraph.co.uk] that does this.
Re:So what happens (Score:3, Informative)
Re:Stupid question (Score:3, Informative)
Gasoline is a very 'dry' fluid. It provides almost no lubricity. Diesel engines need some lubricity in their fuel to lubricate the very high pressure injection system (might be less of an issue with modern common rail systems and piezo injectors though).
Re:bs science as usual- and a waste of time/effort (Score:4, Informative)
Degrading plug wires either cause a misfire, which is blindingly obvious and kills mileage horribly, or doesn't. There is no middle ground. Plug wire misfires happen maybe once or twice in the 300,000 mile life of a (japanese...) car.
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.
Back in the days of points it was different, plug wear and point wear (mostly point wear) had huge effects on mileage between tuneups. These days, the effects are minimal at most.
Re:Stupid question (Score:5, Informative)
Re:Great... (Score:3, Informative)
The more they get into specialized things like this, including laser ignition, the more I worry that I won't be able to be a backyard mechanic any more.
When's the last you were able to backyard mechanic effectively, at least on a "modern" vehicle?
Most are locked down to the point that many of the smaller auto garages around my house have closed up because they couldn't afford to get every single piece of hardware/software to work on the new cars.
Laser-initiated ordnance systems (Score:4, Informative)
We used a similar system starting back in the late 1990s for initiating ordnance systems. The primary explosive would be doped with a small amount of carbon black to enhance absorption. One advantage was that specific equipment was required for proper initiation, which (in theory) made it safer.
Dynamite and a laser beam indeed.
Re:So what happens (Score:3, Informative)
Diesels don't use spark plugs, and already burn all the fuel in the chamber. They run inherently lean, which is why they produce no appreciable carbon monoxide. If you're seeing black sooty exhaust smoke from a diesel, either the fuel rack is turned up too far and it's dumping *way* more diesel in than you can burn, or the air filter is clogged.
Re:Stupid question (Score:2, Informative)
"My truck has spark plugs"
No, it has glow plugs, these only operate when the fuel is cold (ie: at cold start), they stop running when the engine is up to temperature.
"Actually several diesel engines can burn gas for short runs"
No!. Old diesels can tolerate some fuel contaimination, newer common rail, or other high pressure systems can be destroyed by them, with repair values in the $10,000 range.
If you accidentally put petrol in your diesel, do not start it for any reason (This includes moving it away from the pump or onto a tow truck) until the tank and fuel lines have been flushed correctly.
Re:So what happens (Score:3, Informative)
No, sorry that's crap.
Black smoke is due to mechanical failure, either rings allowing sump oil to burn or some other vector allowing oil into the chamber. Too much fuel gives a blue or white smoke. If you get a turbo blow, you get blue smoke out the back, wrong fuel-air ratio. Black smoke is caused by soot. If you have too much fuel that doesn't burn, it can't turn into soot.
Re:Is it just me... (Score:3, Informative)
Spark plugs last just as long as they ever did in the same conditions (although some of the new coatings do extend life under given conditions.) The difference is that the engines are more reliable now, and more importantly not under the control of the driver. When you're not free to dump any quantity of fuel you like into the cylinder, it's a lot harder to end up burning up your plugs.
Re:Flashing lights (Score:4, Informative)
Seems like a good way to get a ticket for impersonating an emergency vehicle.
Indeed. Though it depends on your state, there are restrictions on what lights you can put on a car and in what colors. Many restrict red lights to the back of the car, and some don't allow any light colors than red, white, and yellow on the back of a car (e.g. no neon purple illuminated plate frames). I heard a story from a police officer who pulled someone over just as he left the dealer's lot for having too many high deer lights on his brand new truck; the guy was pissed they'd sold him a car in an illegal configuration.
And just because something is legal in the state in which your car is licensed doesn't mean you won't get ticketed when you cross into another state. Permanent window tinting is another per-state restriction; you may have to drive with your windows open to stay legal, which will suck in states that experience Winter.
Re:So what happens (Score:3, Informative)
Partly, but it was mostly from the low-tech engines used (large mechanical tolerances, no turbocharger, indirect injection, etc.). My 1998 VW New Beetle TDI, which was manufactured well before the switch to ULSD, also produced* very little to no smoke because it has a comparatively modern and high-tech engine. It's not as high-tech as a 2009 TDI engine because it's two generations behind in fuel injection technology (new engines use common-rail injection at very high pressures; mine has a distributor-pump system at fairly low pressures; moderately-high-pressure unit injection systems came between), but it does have a variable-geometry turbocharger, direct injection, etc.
The funny thing is, the older TDIs (like mine) did even better. My mileage is around 35 city/45 highway, and the more-aerodynamic** Golfs and Jettas with the same engine (model years 1999-2003) average about 50 mpg highway easily. The new Jetta is hobbled by three factors: first, it weighs considerably more than the old one. Second, the engine is considerably more powerful (140 HP/236 ft-lbs vs. 90 HP/155 ft-lbs). Third, it's tuned to sacrifice economy in favor of lower emissions.
(* My car would still produce little to no smoke now, even 11 years and 180K miles later, except that I've modded it for more power. It smokes now only during full-throttle acceleration and only moderately, and does so because I've increased fueling but haven't (yet) increased the air flow to compensate.)
(** It's counter-intuitive: the Beetle looks aerodynamic, but it's actually got a drag coefficient of 0.38 (compared to about 0.30 for a 4th-generation Jetta). This is because the smoothly-sloping rear end prevents the flow from separating until it gets all the way down to the bumper, which produces "lift" backwards. See this site [max-mpg.com] for more info.)