Mercedes Power Unit Hardware & Software

[Tommy Cookers]

chamber in the piston crown maybe ? akin to my diesel one
http://i65.tinypic.com/2ufrfvl.jpg

This sounds more like it to me. There is ignition in that little pocket initially.

aye spark onto the pilot injection, then progressively inject the rest of the fuel into that little fireball in the chamber ?
keeps the heat away from the cylinder walls (thermal efficiency)

this recent information is not inconsistent with optimising combustion speed and consistency via a rather homogeneous leanish burn ?
a relatively inhomogeneous burn pattern ie 'keeping heat away from cylinder walls' must be extra hot somewhere or have extra air
neither is without costs ?
(as the rules prevent the compressor and turbine being over 80% efficient)

[gruntguru]

"Perforated Thimble" sounds like Mahle Jet Ignition. http://www.mahle-powertrain.com/en/mahl ... /index.jsp

There is a fair bit of academic literature on the concept if you search for William Attard. He and Prof Harry Watson researched this concept at University of Melbourne. Attard now works for Mahle and where he has published further on the subject.

I am curious as to how Mercedes have done this (if true) as the Mahle system uses two injectors (not permitted in F1.)

It would be possible to have one hole of the DI directed towards the "thimble" to generate the rich mixture there. Or perhaps the DI is in the thimble with the spark plug and most of the fuel sprays align with holes in the thimble.

[trinidefender]

"Perforated Thimble" sounds like Mahle Jet Ignition. http://www.mahle-powertrain.com/en/mahl ... /index.jsp

There is a fair bit of academic literature on the concept if you search for William Attard. He and Prof Harry Watson researched this concept at University of Melbourne. Attard now works for Mahle and where he has published further on the subject.

I am curious as to how Mercedes have done this (if true) as the Mahle system uses two injectors (not permitted in F1.)

It would be possible to have one hole of the DI directed towards the "thimble" to generate the rich mixture there. Or perhaps the DI is in the thimble with the spark plug and most of the fuel sprays align with holes in the thimble.

The rules specify one injector however one injector can have many holes. I'm sure it would be possible to design and manufacture one injector that has some holes for a pilot injection at the side and some for the main injection directly into the centre of the combustion chamber. There can be separate controls circuits for the pilot and main injection events.

Somebody correct me if what I said is in total contravention of the rules.

[gruntguru]

"Perforated Thimble" sounds like Mahle Jet Ignition. http://www.mahle-powertrain.com/en/mahl ... /index.jsp

There is a fair bit of academic literature on the concept if you search for William Attard. He and Prof Harry Watson researched this concept at University of Melbourne. Attard now works for Mahle and where he has published further on the subject.

I am curious as to how Mercedes have done this (if true) as the Mahle system uses two injectors (not permitted in F1.)

It would be possible to have one hole of the DI directed towards the "thimble" to generate the rich mixture there. Or perhaps the DI is in the thimble with the spark plug and most of the fuel sprays align with holes in the thimble.

The rules specify one injector however one injector can have many holes. I'm sure it would be possible to design and manufacture one injector that has some holes for a pilot injection at the side and some for the main injection directly into the centre of the combustion chamber. There can be separate controls circuits for the pilot and main injection events.

Somebody correct me if what I said is in total contravention of the rules.

No problem with the many holes but separate actuator circuits is probably a no-no. Would still be possible with equal duration from all holes. Would require injection timing mapping targeted at producing the required AFR in the "thimble" (approx 1.0)

[Frank_]

could that suggested perforated thimble hang down from the head face (in the middle of the 4 valves) and protrude into the piston pocket ? and maybe house a combined injector and sparkplug ?
then that pocket/bowl could absorb some of the destructive DET forces away from the piston ringlands

[matt21]

As anything else than spark plugs is forbidden, this pre-chamber ignition has to be something on the lines of that:

http://www.google.com.vc/patents/EP2363929A2?cl=en

[pgfpro]

It sounds like a Smart Plug system to me.
http://www.smartplugs.com/index.html
* No Distributor, Coil, Points or Moving Parts
* No Modification to Engine Necessary
* Ignites a Variety of Fuels Fuels
* No Electrical Noise
* No High Voltage
* Non-fouling
* Faster Burn
* Cleaner Burn
* Less Detonation
* Moisture Insensitive
* Can be used on a variety of engines Engines
* Exceptionally High Altitude Capabilities
* Cold Starts Better than a Standard Spark Ignition System
They also have been proven to go way beyond the lean-burn limit of a standard spark ignition.

This is a local company near me that I got to take a tour and see their product working first hand. They have been working with NASA and our US Army and a few of our University's.

[tuj]

I *think* they may be using Pulse Width Modulation to control where during the injection event the fuel is sprayed.

Imagine a short pulse reaching the holes directed at the thimble first, and a long pulse sending fuel through all the holes in the nozzle/injector.

[PlatinumZealot]

They can also use a two stage injector. At lower pre-ignition pressures only the first pintle opens in the prechamber.. then at higher pressure the 2nd stage opens in the main chamber.

The prechamber would be annular in design. ??

[SiLo]

What benefits does this have over normal injection and ignition?

[tuj]

They can also use a two stage injector. At lower pre-ignition pressures only the first pintle opens in the prechamber.. then at higher pressure the 2nd stage opens in the main chamber.

This is legal? Wouldn't it essentially be consider 2 injectors via the rules?

[PlatinumZealot]

What benefits does this have over normal injection and ignition?

I was referring to getting past using the two injectors in MAHLE's pre-chamber design, by using instead, one special injector.

[Edis]

They can also use a two stage injector. At lower pre-ignition pressures only the first pintle opens in the prechamber.. then at higher pressure the 2nd stage opens in the main chamber.

The prechamber would be annular in design. ??

You need to do the main injection first, and the injection into the pre-chamber just before ignition.

Since the injection into the pre-chamber will be done with the piston close to top dead center you could perhaps use an escape path from the pre-chamber into the main chamber for the main injection, and then block this path with the piston once it approaches top dead center and do the second injection to fill the pre-chamber.

[bill shoe]

It sounds like a Smart Plug system to me.
http://www.smartplugs.com/index.html
* No Distributor, Coil, Points or Moving Parts
* No Modification to Engine Necessary
* Ignites a Variety of Fuels Fuels
* No Electrical Noise
* No High Voltage
* Non-fouling
* Faster Burn
* Cleaner Burn
* Less Detonation
* Moisture Insensitive
* Can be used on a variety of engines Engines
* Exceptionally High Altitude Capabilities
* Cold Starts Better than a Standard Spark Ignition System
They also have been proven to go way beyond the lean-burn limit of a standard spark ignition.

This is a local company near me that I got to take a tour and see their product working first hand. They have been working with NASA and our US Army and a few of our University's.

What is it and how does it work? I have strong skepticism when I'm told all the ways X is better without getting any information about how X works.

[godlameroso]

Seems like a chamber with a glow plug that depends on gas to find it's way into the chamber during compression which causes ignition of that chamber's gas. I don't see how it would work only a tiny amount of the fuel mixture is entering the chamber, curious it's not for sale.