Posted on 02/20/2015 6:59:17 AM PST by ckilmer
PEW pew! For a week last November an internal combustion engine hummed away in a lab near Chicago. Why the excitement? This particular engine sets fire to fuel with lasers instead of spark plugs, burning fuel more efficiently than normal. Laser-fired engines could lead to cleaner, greener cars.
(Excerpt) Read more at newscientist.com ...
More efficient combustion means less fuel for the same power out. Less fuel means less waste products.
Re: Retrofit - You would probably have to replace the entire ignition system including the computer controls.
At the end of the article, it talks about a shipping company wanting to retrofit their fleet. Might be possible.
Most newer cars go 100,000+ on a set of spark plugs.
Depending upon the actual improvements in fuel mileage realized, $400-$800 for a set of “laser” plugs every 100,000 miles or so might be economical.
I don't think that is true. A steady push on a moving pistons tends to be better than a instantaneous explosion then waiting for the revolution to complete the cycle.
Higher octane fuels provide resistance to self ignition, igniting too early in the cycle. These fuels used for higher performance engines are not designed to burn more rapidly.
You mean like using propane as fuel for IC engines?
What shipping company is using a gasoline engine requiring spark ignition instead of diesel that ignites under compression?
“be much more explosive”
An exploding mixture in the combustion chamber is what causes engine-harming ping. The mixture in normal operation burns over a small amount of time. There’s a flame front that sweeps across the combustion chamber.
Higher octane gasoline prevents detonation (pinging) at higher compression ratios. Higher compression ratios make engines more efficient which also means more horsepower per engine size.
A higher octane fuel contans no more energy than regular fuel.
The major limit to the efficiency of fuel-burning engines is the limted attainable compression ratio. It’s about thermodynamics. Diesels are more efficient than spark-ignited engines because of their higher compression ratio.
Ships don’t use diesel engines?
On your 'daily driver', it had better last the life of the engine. Replacement is almost guaranteed to be a giant pain in the neck. Industrial (artificial) sapphire and spinel are extremely durable materials, and very transmissive through the realm of reasonable LASER wavelengths:
Okay, now you’re just messin’ with him
Except diesel engines don’t have spark plugs.
The most efficient engine might be a diesel-gasoline hybrid.
http://www.gizmag.com/gasoline-powered-diesel-like-engine/22608/
I used to have a ford ranger with a 4 cylinder engine that had 8 spark plugs in it.
Good call.
The design in question does use a window to isolate the laser from the inhospitable cylinder..
Direct injection and this is a step forward.
I wonder how they go about keeping the light emitter(not sure what they’re called) optic(?) clean and free of the buildup that occurs in engines to keep the lasers working.
The inside of engines tend to be very dirty places, and I’m sure lasers have to be very clean to function.
It’s not being used in a combustion chamber with the shocking changes in temperature and pressure that happen there thousands of times per minute.
The laser is isolated from the combustion chamber via a clear window.
I imagine it was.
Your point makes this sound like a false claim.
I am not saying it could not be done but it wouldn’t as straight forward as a in a gasoline engine where you could unscrew a spark plug and screw in a laser plug.
In a diesel you would have to remove the cylinder heads to machine a new port for the laser to be fitted and a new timing system to fire the laser. Diesels do not have ignition systems because the heat of compression ignites the fuel air mixture not spark plugs.
And I am sure there are a lot of other details I am not thinking of having never worked on a diesel.
I know of a couple of smaller shipping companies running on propane for their shipping trucks.
As for diesel, it might still be possible. I am not an engine designer or a mechanic but I do know that much of the catalytic “stuff” is designed to burn off particulates post combustion. Perhaps a high enough powered laser can burn these within the diesel engine before it is exhausted. Not sure that would provide any additional power but it could treat the exhaust. Perhaps enough to remove the catalytic converters and thus regain the power lost to them???
Just wondering out loud here.
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