F1technical.net

Scratch that - rules only allow one injector per cyl:

"When word of TJI first broke, many publications used illustrations from early Mahle reports and presentations, but the equipment depicted was for a production engine that utilized two injectors per cylinder: one for the main air-fuel charge and a secondary injector just for the ignition chamber. However, Formula 1 allows only a single injector per cylinder, so team engineers had to design a unique combustion chamber with a pre-ignition chamber that supports the spark plug, yet can still draw that 3 percent of fuel from the injector. The final effect is still the same with flame jets coming out of the small chamber and igniting the compressed air-fuel mixture at several points simultaneously in the cylinder."
http://www.enginelabs.com/news/f1-tech- ... -ignition/

My understanding is that there is only one injector, and that like I said, when the piston is on the intake stroke moving down, the vacuum that's created by the down moving piston pulls the main mixture into the cylinder. Then as the piston moves up and cylinder pressure increases it keeps the second fuel charge in the pre-chamber. The pre-chamber mix is ignited, and the flame jets ignite the rest of the mixture. You have to have a very precise fuel injection system.

https://www.motorsport.com/f1/news/ferr ... ea-879930/

With the piston vacuum you're talking about on the intake stroke, wouldn't you have issues since the intake is highly pressurized?

The single injector requirement might explain Ferrari's rumored double anchor injector - one stop fills the cylinder and the other fills the pre-chamber. Would be pretty slick if that's the case.

But ... what about the harmonics?
The simplest solution is to increase the rigidity of the components, maybe weigh 10kg less if you have to add weight to reach the legal limit and also produces vibrations when it is coupled to the transmission is no advantage.

dren wrote: ↑

04 Apr 2017, 20:24

With the piston vacuum you're talking about on the intake stroke, wouldn't you have issues since the intake is highly pressurized?

If the intake manifold is highly pressurized and the cylinder is nearly empty after expelling the exhaust pulse, the pressure inside the cylinder will be much lower than the pressure at the manifold since the intake valves are closed. Once the intake valves open, all that pressure built up in the manifold will rush into the cylinder. I suppose it would cause an issue if you have a bad pre-chamber design.

What about pre-chamber situation after exhaust process. İsn't it filled up by exhaust gas pushed by piston?

JuanjoTS wrote: ↑

04 Apr 2017, 21:53

But ... what about the harmonics?

What about them? It's true that you can generate vortex rings with harmonic resonance.

https://youtu.be/PoEyIJx3uM0?t=3m31s

If you think of the pre-chamber as the little christmas ornaments in this video, you can see that if the main chamber sound frequency, or exhaust frequency resonates with the pre-chamber it could disrupt flame propagation from the pre-chamber.

That is why I'm thinking that it may be a good idea to vary the pre chamber dimensions so that the resonance in the pre-chamber is not tuned to the resonance in the exhaust, or if the inverse is true and resonance improves mixing varying the pre-chamber volume so that the frequency is tuned to the exhaust pulse to improve mixing.

The goal being to avoid the instability of the mixture caused by resonance, so that ignition timing can be set more aggressively, and likewise use a more lean mixture.

etusch wrote: ↑

04 Apr 2017, 22:01

What about pre-chamber situation after exhaust process. İsn't it filled up by exhaust gas pushed by piston?

How if the exhaust valve is open? Even though there's exhaust back pressure, the pressure in the exhaust is much lower than the pressure in the cylinder. Maybe there's some left over gases in the cylinder, natural EGR.

There is no "flame propagation" in TJI type of ignition. ..".Once ignited, the fuel is forced through the orifices 82 of the pre-chamber nozzle 78 such that the flame is extinguished" [ Mahle Patent US8857405 B2 ]

What comes out of the nozzles? Plasma?

godlameroso wrote: ↑

04 Apr 2017, 22:15

JuanjoTS wrote: ↑

04 Apr 2017, 21:53

But ... what about the harmonics?

What about them? It's true that you can generate vortex rings with harmonic resonance.

https://youtu.be/PoEyIJx3uM0?t=3m31s

If you think of the pre-chamber as the little christmas ornaments in this video, you can see that if the main chamber sound frequency, or exhaust frequency resonates with the pre-chamber it could disrupt flame propagation from the pre-chamber.

That is why I'm thinking that it may be a good idea to vary the pre chamber dimensions so that the resonance in the pre-chamber is not tuned to the resonance in the exhaust, or if the inverse is true and resonance improves mixing varying the pre-chamber volume so that the frequency is tuned to the exhaust pulse to improve mixing.

The goal being to avoid the instability of the mixture caused by resonance, so that ignition timing can be set more aggressively, and likewise use a more lean mixture.

The Honda engine problem is the lack of rigidity of its elements, the solution you propose is excessively complicated. The Japanese are extreme, they are white or black, take their concepts too far, less weight is good, but if you add ballast to meet the legal minimum and also produces vibrations seems a pointless concept.

Must find the exact midpoint (gray) between stiffness and weight loss.

The Honda problem is not the inability to inject what they want to each cylinder, use an explosion to push and another to compensate for the created vibrations.
Let's say Honda is running 4.5-cylinder (not bad performance considering this).

The provisional solution that Honda gave in Melbourne was to increase the speed of revolutions to eliminate the greatest possible vibrations, this takes the motor of the ideal torque point and increases the consumption having to save fuel with loss of more power.

In my opinion, the simplest thing is to increase the rigidity of the elements, although this increases the weight of the engine.

They are good news, they are not irreparable errors nor do I think they need 4 races to correct it. They should not be waiting to meet the limit of engines, no matter the penalties, it is important to create the base of the car that will win the 2018-2019 World Cup.

Between the engine at the out-of-par point, fuel savings and having to use cylinders to compensate for vibrations rather than to push, not being able to regenerate enough energy, I think the Honda engine was working at 60% of its potential.

To be more precise, let's take into account that the increased stiffness-weight reduces its ideal potential by 10%, we will say that the Honda engine worked at 70% of its potential.

In this era of F1 so complicated also there is the differential between power to a lap and the power in each lap of a GP. and The Honda engine is more hurt in the race than in a qualifying lap.

Solutions 90% of the time are the simplest, but we tend to eliminate options from the most complicated to the simplest, it is a mistake that we humans make.

godlameroso wrote: ↑

04 Apr 2017, 22:34

What comes out of the nozzles? Plasma?

..With such a rich regulation of the precombustion chamber mixture, products of incomplete combustion were generated comprising a considerable concentration of incomplete combustion stable products, namely, carbon oxide CO and molecular hydrogen H possessing the highest combustion temperature, as well as intermediate products of chemical reactions: peroxides, aldehydes, etc., possessing high chemical activity, especially atoms of hydrogen H and oxygen 0, free radicals-hydroxyl OH, etc., possessing exceptionally high chemical activity...
http://www.google.com.na/patents/US3283751

godlameroso wrote: ↑

04 Apr 2017, 22:34

What comes out of the nozzles? Plasma?

My understanding of this is that the crucible is like a little flamethrower, with perhaps 6 nozzles, all of which eject ignited fuel into the main chamber.

I could be wrong, but i don't think i am.

godlameroso wrote: ↑

04 Apr 2017, 22:34

What comes out of the nozzles? Plasma?

Partially combusted pre-chamber products.
Incomplete combustion of the prechamber mixture results in the formation of CO, H as well as aldehydes, a substantial concentration of peroxides and other active products of intermediate oxidation as well as highly chemical active atoms and free radicals. This results in providing a flame torch of comparatively low temperature and the presence in this torch of the chemically active products of incomplete combustion initiates and speeds up the development of chemical chain reactions in the fuel mixture in the main combustion chamber. This method of prechamber torch ignition results in an increase in the speed of ignition of the fuel mixture in the main combustion chamber of three to four times as compared with conventional spark ignition.