Honda Power Unit Hardware & Software

[godlameroso]

...

It's a mixture of the flames, and unburned free radicals coming out of the plug shroud that ignites the mixture in the main chamber. The gases are driven out of the shroud by the same effect that pushes the pistons down, ie increase in gas temperature.

...

I don’t see the difference between your description and this one.

The ignition chamber is connected to the main chamber by a number of orifices which allow jets of partially combusted products to ignite the main charge.

That’s from the Mahle description of their Turbulent Jet Ignition. https://www.mahle-powertrain.com/en/exp ... -ignition/

What’s the distinctive difference I’m missing?

None, our descriptions are in agreement in how flame jet ignition, and combustion in general work. It's more than just spark flame, heat. There's thousands of steps involving radicals formed at the spark gap, which create further radicals, and as these radicals interact with the hydrocarbons, new bonds are formed, which release heat, and some are broken which absorbs heat. During the combustion process, partially unburned hydrocarbons further release free radicals which again create and break bonds in the A/F mixture. Understanding and modeling these radicals are key to making improvements to both fuel and the combustion process itself.

Elemental nitrogen is a radical by the way, and the fact that these engines have high combustion temperatures and they produce plenty of NOx, perhaps the process makes use of elemental nitrogen to some extent.

[saviour stivala]

A Honda engineer was quoted (not a journalist forming an opinion) about the use of a pre-chamber in the 2017 PU. He said it was difficult to balance the A/F ratio in the pre-chamber and the main chamber with the injector spray and air flow. He said you cannot get away from using pre-chamber ignition in the current PU formula when you want to raise combustion efficiency.

Perhaps the pre-chamber is part of the piston crown and open to air/fuel up until TDC when it encapsulates the top protruding spark plug?

My fancy paint skills:
https://image.ibb.co/e7MDFA/pre.png

Isn't that too late for ignition?

I actually read two different articles by the same Japanese F1 site (text=Kota Sera – photos=Hidenobu Tanaka, that is after both of them had been translated. In one a Honda engineer by the name of MR Kakuda was quoted, in the other article a Honda engineer by the name of MR Hasika was quoted. On 26 Oct I contacted the Japanese USA based translator of the last article and asked him to shed light on MR Hasika official rank/position at Honda. On the same day the Japanese USA based translator responded to my request “Sorry I don’t anything about ‘HASIKA’”.
Somebody said-it/wrote-it, a lot read-it, some believed-it, still to this day some are still parroting-it.

[saviour stivala]

...

It's a mixture of the flames, and unburned free radicals coming out of the plug shroud that ignites the mixture in the main chamber. The gases are driven out of the shroud by the same effect that pushes the pistons down, ie increase in gas temperature.

...

I don’t see the difference between your description and this one.

The ignition chamber is connected to the main chamber by a number of orifices which allow jets of partially combusted products to ignite the main charge.

That’s from the Mahle description of their Turbulent Jet Ignition.
What’s the distinctive difference I’m missing?

There is a big difference to the Mahle turbulent jet iginition, the Mahle TJI https://www.mahle-powertrain.com/en/exp ... -ignition/ shows an injector right inside the pre-chamber sharing the space with a spark-plug, which means the injector injects fuel inside the pre-chamber.

[henry]

....

None, our descriptions are in agreement in how flame jet ignition, and combustion in general work. It's more than just spark flame, heat. There's thousands of steps involving radicals formed at the spark gap, which create further radicals, and as these radicals interact with the hydrocarbons, new bonds are formed, which release heat, and some are broken which absorbs heat. During the combustion process, partially unburned hydrocarbons further release free radicals which again create and break bonds in the A/F mixture. Understanding and modeling these radicals are key to making improvements to both fuel and the combustion process itself.

Elemental nitrogen is a radical by the way, and the fact that these engines have high combustion temperatures and they produce plenty of NOx, perhaps the process makes use of elemental nitrogen to some extent.

No doubt the actual combustion processes are very complex. But surely in a discussion of TJI that’s not the key issue.

In a TJI solution there is a small chamber in which combustion is initiated by a spark and then the combustion products are ejected in a controlled manner into a larger chamber where those combustion products cause ignition. The process is spark, burn, eject, burn.

In your post above you seem to agree with this characterisation and show a shrouded plug, with a small chamber and ejection holes.

Whilst it is obviously important that the actual chemistry supports this, and there are almost certainly some specifics that are beneficial to the differing fuel-air ratios in the two chambers, as far as I can see the chief difference for a TJI concept is how the spark chamber is formed and how the air movements and injection patterns form the two environments in which the combustion processes operate.

The alternative to TJI is that the differing fuel-air ratios are generated within the space of the combustion chamber by some form of stratification. It seems unlikely that at the extreme air-fuel ratios used reliable ignition could happen in a homogenous charge.

[dren]

Somebody said-it/wrote-it, a lot read-it, some believed-it, still to this day some are still parroting-it.

So, what is your theory on the combustion process Honda is using?

[dren]

A Honda engineer was quoted (not a journalist forming an opinion) about the use of a pre-chamber in the 2017 PU. He said it was difficult to balance the A/F ratio in the pre-chamber and the main chamber with the injector spray and air flow. He said you cannot get away from using pre-chamber ignition in the current PU formula when you want to raise combustion efficiency.

Perhaps the pre-chamber is part of the piston crown and open to air/fuel up until TDC when it encapsulates the top protruding spark plug?

My fancy paint skills:
https://image.ibb.co/e7MDFA/pre.png

Isn't that too late for ignition?

It wouldn't necessarily have to be at TDC. The pre-chamber piston can start to seal into the spark plug shroud before TDC.

[stevesingo]

A Honda engineer was quoted (not a journalist forming an opinion) about the use of a pre-chamber in the 2017 PU. He said it was difficult to balance the A/F ratio in the pre-chamber and the main chamber with the injector spray and air flow. He said you cannot get away from using pre-chamber ignition in the current PU formula when you want to raise combustion efficiency.

Perhaps the pre-chamber is part of the piston crown and open to air/fuel up until TDC when it encapsulates the top protruding spark plug?

My fancy paint skills:
https://image.ibb.co/e7MDFA/pre.png

Isn't that too late for ignition?

It wouldn't necessarily have to be at TDC. The pre-chamber piston can start to seal into the spark plug shroud before TDC.

I would also add that such an ignition system is designed to promote a faster more complete combustion and as such, less advance would be required.

[dren]

Isn't that too late for ignition?

It wouldn't necessarily have to be at TDC. The pre-chamber piston can start to seal into the spark plug shroud before TDC.

I would also add that such an ignition system is designed to promote a faster more complete combustion and as such, less advance would be required.

True, more instantaneous rather than a propagating flame.

[saviour stivala]

Somebody said-it/wrote-it, a lot read-it, some believed-it, still to this day some are still parroting-it.

So, what is your theory on the combustion process Honda is using?

My theory= a supposition of a system of ideas based on general principles, cannot be any more and cannot be any less. as long as what is being used by the respective four is such a highly guarded secret. maybe when time passes and this present combustion development is Superseded by a more advanced development we will get not only to know but also see with our own eyes like what happened with the “write-up” permission of the FERRARI 2000 winning car publication, the first of its kind in such a secretive technical matters.

[saviour stivala]

....

None, our descriptions are in agreement in how flame jet ignition, and combustion in general work. It's more than just spark flame, heat. There's thousands of steps involving radicals formed at the spark gap, which create further radicals, and as these radicals interact with the hydrocarbons, new bonds are formed, which release heat, and some are broken which absorbs heat. During the combustion process, partially unburned hydrocarbons further release free radicals which again create and break bonds in the A/F mixture. Understanding and modeling these radicals are key to making improvements to both fuel and the combustion process itself.

Elemental nitrogen is a radical by the way, and the fact that these engines have high combustion temperatures and they produce plenty of NOx, perhaps the process makes use of elemental nitrogen to some extent.

No doubt the actual combustion processes are very complex. But surely in a discussion of TJI that’s not the key issue.

In a TJI solution there is a small chamber in which combustion is initiated by a spark and then the combustion products are ejected in a controlled manner into a larger chamber where those combustion products cause ignition. The process is spark, burn, eject, burn.

In your post above you seem to agree with this characterisation and show a shrouded plug, with a small chamber and ejection holes.

Whilst it is obviously important that the actual chemistry supports this, and there are almost certainly some specifics that are beneficial to the differing fuel-air ratios in the two chambers, as far as I can see the chief difference for a TJI concept is how the spark chamber is formed and how the air movements and injection patterns form the two environments in which the combustion processes operate.

The alternative to TJI is that the differing fuel-air ratios are generated within the space of the combustion chamber by some form of stratification. It seems unlikely that at the extreme air-fuel ratios used reliable ignition could happen in a homogenous charge.

Possibilities that "differing fuel-air ratios are generated within the space of the combustion chamber" I personally believe that there is very little possibility if any of therec being 'differing fuel-air ratios' inside a formula 1 engine cylinder when as i belive the fuel is being injected at a pressure of 500bar and at least 60 degrees BTDC and before being fully compressed.

[saviour stivala]

A Honda engineer was quoted (not a journalist forming an opinion) about the use of a pre-chamber in the 2017 PU. He said it was difficult to balance the A/F ratio in the pre-chamber and the main chamber with the injector spray and air flow. He said you cannot get away from using pre-chamber ignition in the current PU formula when you want to raise combustion efficiency.

Perhaps the pre-chamber is part of the piston crown and open to air/fuel up until TDC when it encapsulates the top protruding spark plug?

My fancy paint skills:
https://image.ibb.co/e7MDFA/pre.png

Isn't that too late for ignition?

It wouldn't necessarily have to be at TDC. The pre-chamber piston can start to seal into the spark plug shroud before TDC.

combustion that starts at one place and continues at another place such as a pre-chamber system is in my opinion not conductive to a 10500 RPM max power speed system of operation.

[aral]

OK, a lot of this is way above me, however, SS, dont get hung up on the 10500 rpm as being max rpm. You will see for instance that during a race, the Merc is getting up to 12000 rpm. I am not sure if this spoils your calculations, but certainly 10500 rpm is no longer a maximum in use.

[subcritical71]

Somebody said-it/wrote-it, a lot read-it, some believed-it, still to this day some are still parroting-it.

You of all people accusing forum members of parroting or fommenting is quite funny.

Any luck finding that 'direct injection' rule you referenced yesterday?

[Dr. Acula]

combustion that starts at one place and continues at another place such as a pre-chamber system is in my opinion not conductive to a 10500 RPM max power speed system of operation.

Sorry, but that's what generally happens if you have spark ignition anyway. It's not that the whole mixture inside the combustion chamber would ignite in an instant when the spark plug fires, regardless of the design of the combustion chamber. The flame travels away from the spark plug through the entire combustion chamber once ignition has happend. And we saw engines with a conventional system doing 20'000rpm just about a decade ago. Flame propagation speed is higly dependend on the stoichiometric ratio, the pressure inside the combustion chamber pre ignition, the fuel itself and if the flame propagation happens laminar or turbulent.
The last point has actually the highest impact by far and can change the flame propagation speed by more than 3 orders of magnitude compared to a strictly laminar flame propagation, although torwards the higher orders of magnitude you would start to call it an explosion.
Also Mahle wrote about their TJI design, it would actually accelerate the combustion. Which in my opinion makes sense. Because to put it simply, it's like trying to ignite the main chamber with a tiny little spark which is known to not work very well if you try to lean out the mixture to much or to try the same with some kind of flame thrower. Which one would you think will have the faster combustion of the main chamber overall. That's regardless if you think TJI is used in F1 or not. But to say that TJI isn't suitable for high rpm applications is BS in my opinion.

With 4-8 ignition jets, depending on the application, the main charge is extensively ignited and a faster burn-through and pressure build-up is generated.

[tcooper27]

Somebody said-it/wrote-it, a lot read-it, some believed-it, still to this day some are still parroting-it.

So, what is your theory on the combustion process Honda is using?

My theory= a supposition of a system of ideas based on general principles, cannot be any more and cannot be any less. as long as what is being used by the respective four is such a highly guarded secret. maybe when time passes and this present combustion development is Superseded by a more advanced development we will get not only to know but also see with our own eyes like what happened with the “write-up” permission of the FERRARI 2000 winning car publication, the first of its kind in such a secretive technical matters.

So you have no theory that you think is good enough to contribute but you're 100% sure they're not using TJI because a third party translator doesn't know anything about a specific engineer at Honda?

Do you have any experience in prototype engine development or advanced combustion technologies to back up your claims? Any real evidence that they're using something other than what they're publishing? Any reason to believe Honda is lying to all of us through these publications? Anything at all?