saviour stivala wrote: ↑
Thu Nov 08, 2018 12:53 pm
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.
Mahle wrote: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.