Cars to be started by lasers instead of spark plugs

[Kiwi Tinker]

I saw this and thought it was interesting

http://www.telegraph.co.uk/motoring/...ark-plugs.html

Cheers


Robert

[platinum]

That would give a whole new meaning to "Plymouth Laser"...

-Jonathan

[shrad]

I hope they use a blue diode but that's not really realistic

might be a 808nm diode though, as they are the most readily available and cheapest ones

[danielbriggs]

I was looking around at Liverpool University about 18 months ago, and I got to see this in person. It was a PhD student's research project. From what I remember it was (at that time) on a very large optical table (can't remember what the main laser used was) but there were several HeNe's for alignment I presume...
The engine under test was bolted on a frame to the floor

Dan

[jeejeedr]

I'm just wondering how they keep their optics clean inside the cylinder.

[Doc]

I'm just wondering how they keep their optics clean inside the cylinder.

If the temperature is high enough it will be self cleaning, much like DPFs and catalysts.

[White-Light]

But electronics and high temperatures don't get along though. Surely there will be cooling issues or a short lifetime if the temperature is high.

I'm also failing to see the advantage in using a laser over an electrical spark. Perhaps more accurate timing for greater efficiency and economy?

[Doc]

I would be supprised if this wasn't some new diesel technology, to this day we are still relying on compression ignition, and hence the "diesel delay" knock that is inevitable. With some kind of forced ignition (spark ignition is not really practical at diesel compression pressures), they could make a diesel run as quiet as a petrol fuelled engine.

[shrad]

if they use a long wavelength, it is possible they use some IR-passing ceramic optics

also, if they use fiber optics, there is no worry about heating electronics

what is nice is it is possible to optimize the combustion by spectroscopic means, if they recover the beam after it has been focussed (for example, an optical coupler left side of the combustion chamber, focal point in the middle, and then a second optical coupler right side of the chamber to get the beam back for analyses)

[mixedgas]

This is just a civil derivative of something Uncle Sam has been doing for quite some time now.

fiber to the engine is quite practical and its the peak power that matters, not the pump diode.....

I did a small study for my former employer two years ago. Some of you might not know my avatar is a 20 hz 110V 7 nS 50-100 mJ lamp pumped yag...... A small "Snapper" if you will.... With a focusing lens that had the high quality glass in it, it would maintain a plasma ball in front of the laser whenever enough dust was in the air, in a clean room you had to hold something there for it to blast to start the plasma and then it sustained it. focusing lenses that had poor quality glass set on desks as conversation pieces. NOTE, this is a pockels cell, not a AO q-switch, which gets you that nice "snap"

A plus is that a air breakdown usually needs something to nucleate on, a little dust etc, and there are plenty of fuel droplets in there, actually makes the task quite easy.

I imagine with some work, the optics will be self cleaning. BTW, windows into combustion chambers have been used since the 60s in automobile engine R&D, for things like flow diagnostics, doppler velocimetry, and looking at the flame front.

Its really just a matter of getting the cost down and proving some utility.
But a spark plug is hard to beat unless your racing.... Uncle has other uses for the technology....
Steve