Laser spark plugs

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http://www.autoblog.com/2011/04/24/l...sh-in-the-pan/

Laser spark plugs: bright idea or flash in the pan?

by Dan Roth (RSS feed) on Apr 24th 2011 at 2:06PM

he internal combustion engine for automotive use is highly engineered and run by advanced electro-mechanical systems that have been refined over a century of development. That fact hasn't stood in the way of breathless reports about laser spark plugs being the next big thing. Fast Company goes as far as to disparage the gasoline engine as antiquated and filthy while calling exotic and expensive laser ignitors "the gas engine's last gasp before the electric revolution comes."

Laser spark plugs do sound pretty neat. In Japan, researchers at the National Institute of Natural Sciences have cooked up an exceptionally compact laser that's robust enough for automotive use. With lots of strong ceramics and two different yttrium-based laser elements, one doped with neodymium and the other chromium, the lasers are capable of being pulsed more quickly and more accurately than current spark plug technology allows. Another benefit of lasers in the combustion chamber is the ability to ignite the air/fuel mixture with more power than a spark plug can reliably dissipate.

Modern engine management systems and direct fuel injection are capable of exceptional efficiency and more complete combustion than ever before, and gasoline contains a lot more energy per pound than any current automotive battery technology. While spark plugs might seem antiquated, they're far cheaper than fitting lasers for ignition, and the ignition systems attached to those plugs continue to get more and more sophisticated.

None of this research work has been applied to an actual engine yet, making any claims of superiority mere academia at this point. The NINS work will be presented at the 2011 Conference on Lasers and Electro Optics that's happening in early May. While there's great potential for small lasers that can stand up to harsh environments, and the developers are working with suppliers and automakers, it's not likely that your engine will be lit off by an Nd/Cr:YAG any time soon, despite what the car-haters who skim over engineering facts might have to say.

[Source: Fast Company]

[AWD Chaser]

Old news - Ford have been developing this for a while - I think there was a post on it last year...

[chevypower]

Can they be removed from a 5.4 3 valve without breaking?

[2011G6E]

You know, when you think about it, the spark plug is the one part of an internal combustion engine that is still pretty much identical to the very first plugs over a century ago. Materials might have changed, but if you went back in time and showed a motorist from 1900 a modern Iridium $30 spark plug, he'd immediately know what it was.

About time something better came along...

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It’s called a pulse plug – and here’s why its technology should be in your engine.

Until now, every gallon of gas you bought was ignited by a simple spark plug- an outdated technology that has barely changed in 100 years. But now you can change to a new eco-friendly pulse plug that uses an advanced technology to make every drop of gas burn better and cleaner.

Here’s how it works: Electrical energy from the engine’s ignition coil is stored in the built-in capacitor. At the exact moment needed, that energy is released in an amazingly powerful and quick (two nanosecond) high-energy pulse.

The result: The improved combustion efficiency burns fuel sooner and more effectively, which equals improved mpg, less CO2 based emissions, and better overall drivability. Even the green get greener! For example, in this EPA US06 fuel consumption lab test, even the icon of fuel economy and eco-friendliness- the Toyota Prius- saw notable improvements in mpg.

This new technology is based on plasma research supported by the world famous Sandia National Laboratories – and yes, that’s definitely rocket science.

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Lasers move closer to replacing spark plugs

http://www.goauto.com.au/mellor/mell...25787F000F6EF3

Researchers unveil laser ignition system designed to boost petrol engine efficiency

27 April 2011

By HAITHAM RAZAGUI

LASER igniters might replace spark plugs in petrol engines to improve their efficiency, thanks to a team of Japan-based researchers who will present their laser development to the Conference on Lasers and Electro Optics in Baltimore next week.

Compared with conventional spark plugs, which ignite the air/fuel mixture closest to them and create a flame front that spreads throughout the combustion chamber to force the piston downwards, laser beams can be accurately focussed to start the combustion at the most efficient point.

The researchers from Japan's National Institutes of Natural Sciences claim that because the flame front generated by a spark plug travels across the relatively cool surfaces of the combustion chamber as it starts to expand, some of its energy is lost.

A laser can avoid this by focussing the beam into the centre of the combustion chamber. Team member Takunori Taira said this caused the flame front to expand more symmetrically and up to three times faster than it would if ignited by a spark plug.

In addition, several beams can be used simultaneously for an even faster, more complete burn and lasers can be more precisely timed than spark plugs – in nanoseconds as opposed to milliseconds – resulting in more efficient combustion.

Although spark plugs have the ability to ignite lean fuel/air mixtures, a limitation of the technology is that the increased spark energy required causes the spark plug electrodes to degrade rapidly.

Laser ignition circumvents this limitation because lasers are able to inject enough energy to the combustion chamber to ignite a lean fuel/air mixture without being subject to the wear that necessitates the regular replacement associated with spark plugs.

The faster, more accurate and leaner combustion made possible by laser ignition results in improved fuel economy and reduced emissions – particularly NOx, which contributes to smog.

The research was funded by the Japan Science and Technical Agency with support from Denso – a major vehicle component manufacturer and part of the Toyota Group.

The team is working with an unnamed large spark-plug company (which could be the Japanese firm NGK) and Denso to explore the possibilities of bringing the technology to market.

Using lasers to replace the spark-plug – which has been around since 1860 and first made commercially viable by Robert Bosch in 1898 – is not a new idea.

In 2006, Colorado State University filed a US patent for a special type of optical fibre that could withstand the high levels of energy required to create a spark in an internal combustion engine.

In 2009 Liverpool University in the UK, in collaboration with Ford Motor Company, did research into using laser to power combustion in mass-produced petrol engines. The researchers successfully ran a four-cylinder engine using laser ignition, recording smoother running and reduced exhaust emissions.

However, the British team met problems delivering the beam to what they called the optical spark plug via fibre-optics and could only use it by aiming the separate laser unit’s beam directly into the engine – making it impractical for commercial use.

Mr Taira’s Japan-based team was well aware of the limitations faced by other researchers into the field of laser ignition.

“In the past, lasers that could meet (the) requirements were limited to basic research because they were big, inefficient, and unstable,” he said.

As the Liverpool and Colorado Universities found and attempted to overcome, the lasers could not located away from the engine because their powerful beams would destroy any optical fibres that delivered light to the cylinders.

Mr Taira’s team has circumvented the problems by using ceramics to make a powerful composite laser just 9mm wide by 11mm long that generates two beams that can simultaneously start combustion in separate areas of the combustion chamber – and the team is also working on a three-beam laser.

The benefit of using ceramics, other than their effectiveness in dissipating the engine’s heat, is that they are easier to tune optically than conventionally-used crystals, while being stronger and more durable.

Although the laser is not strong enough to ignite lean fuel/air mixtures with a single pulse, it overcomes this by using several 800 picosecond (a picosecond is a trillionth of a second) pulses to inject enough energy to the combustion chamber for ignition.

Internal combustion may appear to be going out of fashion as a means of vehicle propulsion but mankind’s faith in its ability to refine the technology for greater efficiency would suggest that we haven’t seen the back of it yet.

In the race to squeeze every last drop of efficiency from the petrol engine, scientists and engineers like Mr Taira are beginning to view the humble spark plug as the weakest link.

In addition to the laser beam idea, another school of thought, being pursued by General Motors, is to use compression ignition for petrol engines – like a diesel engine, using the heat generated by compression to ignite the fuel/air mixture.