7 ms·
It's all fine and dandy till a speck of soot blocks the optics, and the engine dies. A better solution (IMHO) would be to have multiple spark plugs.
by ajays 15y ago
It's all fine and dandy till a speck of soot blocks the optics, and the engine dies.
A better solution (IMHO) would be to have multiple spark plugs.
- eco 15y agoYou should file a patent. I'm sure the automotive industry has not thought of using multiple spark plugs.
- lutorm 15y agoYeah that seems like an obvious problem to anyone who's looked inside a combustion chamber. I wish they'd mentioned something about how they think this is not a problem.
- jimmyk 15y agoIt seems to me like that kind of concentrated power would be capable of vaporizing any small particles (or even turning them into plasma briefly) in the way.
- lutorm 15y agoMaybe, but they say that it's focused in the center of the chamber because that's where you want ignition to start. In that case, you might not have that high flux at the entry aperture (you might not want this for other material reasons, too). In any case, I don't think you want to start combustion at the edge because that's the least efficient place to do it.
- mhb 15y agoMaybe the beam is wide enough before it is focused so that the soot wouldn't block enough of it to be a problem before the soot is blown out of the chamber.
- lutorm 15y ago... before the soot is blown out of the chamber. You've never looked inside an old engine, have you?
- mhb 15y agoNo. But I only intended to address the point that if the beam is focused in the center then it would take more than a speck of soot to block the wider, lower flux, defocused beam where it enters the cylinder.
- ars 15y agoCarbon has a very high melting point, never mind boiling point. If you would heat it up that much you would melt the optical port. However, you can simply heat the carbon (all that energy has to go somewhere). Once it's hot enough it can burn in the chamber - and it would probably be hot enough to ignite the fuel as well. That said, I don't think soot is that common anyway. Normally you run lean which prevents soot. It does need to be able to self clean, but occasional poor efficiency from soot should not be common enough to hurt.
- gallerytungsten 15y agoI was wondering about that too. Perhaps the laser is powerful enough to be "self-cleaning" and blast through the soot.
- mkr-hn 15y agoDepends on whether or not the soot is transparent on the part of the spectrum the laser operates at.
- fleitz 15y agoAn even better solution for efficiency is no spark plugs. http://en.wikipedia.org/wiki/Diesel_engine http://en.wikipedia.org/wiki/Diesel_engine
- johngalt 15y agoBeen done. Imagine my surprise when I went to tune up my 4-cyl nissan pickup and had to replace 8 plugs. http://en.wikipedia.org/wiki/Nissan_Z_engine#Z24 http://en.wikipedia.org/wiki/Nissan_Z_engine#Z24 On the plus side, the truck still runs clean (300,000 miles later) and gets great mileage.
- dtegart 15y agoTo be fair, if your engine is running rich, soot will prevent spark plugs from being able to spark.