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Laser Ignition May Replace the Spark Plug

Posted by kdawson on from the what-could-possibly-go-wrong dept.

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."

4 of 388 comments (clear)

  1. So what happens by Anonymous Coward · · Score: 5, Interesting

    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?

    1. Re:So what happens by fuzzyfuzzyfungus · · Score: 4, Interesting

      I'm not worried about the amount of energy getting to the cylinder, that can just be brute forced as you note. I'm more concerned about what the energy that doesn't make it will do. Fiber fuse could be fairly dramatic in such a system. Video of fiber fuse propagating.

      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.

    2. Re:So what happens by shiftless · · Score: 4, 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.

  2. Lifetime? by Anonymous Coward · · 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.)