lasers instead of sparkplugs

[fourier jr]

could this work? some of the comments say stuff about power & voltage, etc which I don't know anything about. Cool idea but I still think there are better ways to power a car:

Equally significant, the new laser system is made from ceramics, and could be produced inexpensively in large volumes, according to one of the presentation's authors, Takunori Taira of Japan's National Institutes of Natural Sciences.

According to Taira, conventional spark plugs pose a barrier to improving fuel economy and reducing emissions of nitrogen oxides (NOx), a key component of smog.

Spark plugs work by sending small, high-voltage electrical sparks across a gap between two metal electrodes. The spark ignites the air-fuel mixture in the engine's cylinder—producing a controlled explosion that forces the piston down to the bottom of the cylinder, generating the horsepower needed to move the vehicle.

*snip*

Equally important, he says, lasers inject their energy within nanoseconds, compared with milliseconds for spark plugs. "Timing – quick combustion – is very important. The more precise the timing, the more efficient the combustion and the better the fuel economy," he says.

Lasers promise less pollution and greater fuel efficiency, but making small, powerful lasers has, until now, proven hard. To ignite combustion, a laser must focus light to approximately 100 gigawatts per square centimeter with short pulses of more than 10 millijoules each.

http://www.physorg.com/news/2011-04-laser-revolution-internal-combustion.html

[Dr Lots-o'watts]

Quite interesting. Seems like the problem is mostly about miniaturizing, and they seem to be on a good track.

[Mech_Engineer]

It's a pretty cool idea. It could be a challenge to keep the final optics clean in the combustion chamber, they would probably have to make it self-cleaning and replaceable.

[brewnog]

It's been 5 years away for the past 20 years or so.

[matchinu]

would this sort of technology work to self clean the laser http://thefutureofthings.com/news/1018/nanofibers-to-create-self-cleaning-windows.html

"Using nanofibers, the group developed different kinds of surfaces - some are water-repellent, some attract water, and some even repel oil and dirt. "

[Bob S]

could [lasers instead of spark plugs] work? some of the comments say stuff about power & voltage, etc which I don't know anything about. Cool idea but I still think there are better ways to power a car:
You need to create lots of ions to ignite the fuel-air mixture. To create ions you need volts per cm to create a spark, or use a laser to create ions. Look at this list of ionization energies of the elements, in particular hydrogen, nitrogen, and oxygen:

http://www.science.co.il/ptelements.asp?s=ionization

Also look at

http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA432572

To ionize hydrogen, nitrogen, or oxygen, you need to knock off an electron. You first must find a 100-nanometer (ultra-violet) laser. Good luck.

Bob S

[MATLABdude]

You need to create lots of ions to ignite the fuel-air mixture. To create ions you need volts per cm to create a spark, or use a laser to create ions. Look at this list of ionization energies of the elements, in particular hydrogen, nitrogen, and oxygen:

http://www.science.co.il/ptelements.asp?s=ionization

Also look at

http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA432572

To ionize hydrogen, nitrogen, or oxygen, you need to knock off an electron. You first must find a 100-nanometer (ultra-violet) laser. Good luck.

Bob S

If you have good optics and high beam quality, you can ionize air (semi-independent of the laser wavelength) by getting the focus tight enough:
http://www.rp-photonics.com/laser_induced_breakdown.html
http://laserpointerforums.com/f54/air-ionization-lasers-60415.html

Very dramatic (I was a half-asleep undergrad during a lab tour once, when the prof leading the tour decided to show off his laser--not the incident in the video):
http://www.youtube.com/watch?v=1HHJhpStza0

But those are big, powerful, and expensive lasers, along with expensive optics.

[Bob S]

If you have good optics and high beam quality, you can ionize air (semi-independent of the laser wavelength) by getting the focus tight enough:
http://www.rp-photonics.com/laser_induced_breakdown.html
http://laserpointerforums.com/f54/air-ionization-lasers-60415.html

Very dramatic (I was a half-asleep undergrad during a lab tour once, when the prof leading the tour decided to show off his laser--not the incident in the video):
http://www.youtube.com/watch?v=1HHJhpStza0

But those are big, powerful, and expensive lasers, along with expensive optics.

Nice. I was thing about that when I wrote my post, but I didn't think the laser(s) would fit under the hood.

Ignition spark timing is good to better than ≈ 100 microseconds with the old pre-1970 circuits, and probably 5 x better using transistorized CD (capacitor discharge) circuits. A more efficient way is to heat the fuel itself using adiabatic compression (diesel engine).

Bob S