http://www.autoblog.com/2011/06/28/mazda-rumored-to-use-laser-ignition-for-next-gen-rotary/

http://m.motortrend.com/wot/we-hear-next-mazda-rotary-engine-to-employ-laser-ignition-91085.html


-Dan Gorsline.


Wankel Rotary Power


This is 2011 if it worked it would be here by now.
A laser with enough power is not inexpensive.

Paul Lamar

No doubt that lasers can be used to spark and the benefits of a
distributed ignition within the chamber are obvious

Lasers are now made "dirt" cheap and are highly reliable (20 years
continuous use). A small 2" wafer can be diced into 10,000 semiconductor
lasers the size of a grain of salt. There is a 99.999% chance that this
email arrived to everyone after passing several lasers and several EDFA
(Optical Amplifiers driven by another laser) over fiber optics

The technical challenge is the keeping the lens into the chamber clean
enough over time to keep working. Lasers need a translucent window /
lens made from quartz or sapphire. These are also readily available and
relatively cheap. The challenge is keeping the quartz window clean and
free from soot build up over time. As soot and other combustion deposits
builds up on the window/lens, it becomes opaque and unable to pass the
laser light

Several companies are working on this including a division of DENSO
(second largest global auto industry supplier) but it will be a long
time, if ever, before we see it in production
(PS I spent 16 years in the laser industry)
Regards
Simon Sab

What are the typical powers of a laser the size of a grain of salt?
Are there any fast laser optical isolators available?
Fast in the region of nanoseconds. Maybe the problem is not
the laser but the optical transistor or detector come to think of it.

Paul Lamar

Depending on the wavelength, these lasers can go to 10 Watts at the 920
nanometer range
for lasers anything in the Watt region is very high power (enough for
metalworking). In general, lower wavelength lasers, the photons have
more energy

I am not sure what wavelength rage is best to achieve spark ignition. I
remember reading a lot a paper about using the 1550 nanometer region to
leverage the huge volume of telecommunications lasers. The attached data
sheet shows the laser are roughly 1" x 0.5"  0.5" form factor but 90% of
that volume is the heat sink. This is a fiber coupled laser meaning the
laser can be 1 to several meters away from the engine.

In general lasers can be modulated at very high frequency. When I left
the industry a few years ago 10GHz modulation was considered "old
technology" and the next frontier was 25 GHz and 40 GHz

There is a US company called princeton optronics doing some work in this
area https://www.sbir.gov/sbirsearch/detail/689475

There are others years ahead of Princeton Optronics researching this,
but nothing came close to commercialization

Regards
Simon Sab

Thanks for the info Simon.



Paul Lamar


Hi Paul
you are welcome,
This link may be helpful as well. Dr Byer from Stanford was in this conference and he is very well known in lasers and optics industryhttp://lic.opicon.jp/archives/2013/index.html

If any engine has a chance to leverage laser ignition, it is a rotary engine. The reason is that the side seals can act as a continuous "windshield wiper" to keep "cleaning" the quartz window so that the laser light always enters the chamber. In fact one of the ideas I was kicking around and considering filing a patent for, is pointing the laser as a slight angle, the surface on the other side will reflect typically 90 to 95% for each reflection (since it also is continuously being "polished". What this means is a potential to have a back and forth zigzag line ignition rather than point ignition. Lasers naturally diverge but you can still achieve a good ignition over 20 to 30 cm long linear line inside different regions of the chamber simultaneously which I think would guarantee full ignition and full combustion. This is especially beneficial for the long and very narrow chamber at the beginning of the power stroke in a Wankel in order to accelerate the process and allow more time for expansion

With the killing off of the Wankel by Mazda, I thought the revenue opportunity for such a patent would be limited and these days it's around $15K just for a US patent, and probably $40 K to get coverage in the US/Germany and Japan. When I have better funding, I may file it just as a defensive patent since we could benefit from that as well (but our challenge is less extreme than in a Wankel, because the chamber length to width is much less severe). For now, I am using a standard ignition and would like to test your multi spark system as well as the ASIC Corona sparks that Federal Mogul is commercializing. I think both will have the same effect on improving ignition to achieve a more comprehensive combustion, although I believe your approach would be far more predictable, repeatable and uniform, hence superior to the Federal Mogul approach
ps if you want to discuss further, please feel free to call me                Regards
Simon Sab

The Mazda Wankel is not dead yet. Rumour has it there is a 350 HP turbo compound hybrid
in the works similar to F 1 engines. We must restore the capitalist economic health
of the US so innovation and invention can continue. Nobody invents anytrhing
in a socialist economic system. There is no excess money for R&D and no monetary incentive.

Paul Lamar

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