Regarding homogeneous Lambda 2: The current development is for DI, no charge heating and significant rpm and load range (basically the part of the engine map you can cover with the amount of air you can provide at a certain engine speed with the given turbocharger). But that's a side note here, because that's development for series production. The one I'm talking about is not even involved in F1.Tommy Cookers wrote:we have seen from Honda via Green Car Congress that gasoline homogeneous 2 lambda is possible ......
only with port injection (charge preparation) combined with charge heating combined with a lot of turbulence, and only at low rpm
unless the F1 fuel has the combustion properties of a small gas molecule how will it combust fast and fully beyond 2 ?
(by stuffing it with 'natural' dissolved propane/ethane as I suggested 2-3 years ago, and maybe the pre-chamber/TJI is mainly such gas ?)
The "standard" approach to get really lean (beyond lambda 2) is to go for a stratified combustion system, so inhomogeneous charge preparation where you have an ignitable air/fuel mixture at the spark plug, but not close to the surfaces of the combustion chamber. That also has benefits with the amount of heat transferred to the cylinder, piston and head. However, the charge motion design is quite a challenge, especially over the time of a production vehicle, not so much for motorsport. Hence, only Mercedes is still doing it in a couple of engines for series production.
For F1, I would assume that some kind of inhomogeneous charge preparation takes place, what with the alleged prechamber/TJI situation of different manufacturers and what not. That's probably all I should say in that regard, since it's one of the more closely guarded areas of these PUs.
The findings from the current F1 developments should be interesting for future road use to some regard, which is interesting. Since in the EU WLTP+RDE regulations are now relevant, there's very little chance to avoid the GPF and fuel consumption targets are going to be more difficult. Maybe that will allow for the increased costs of lean exhaust aftertreatment for gasoline engines. That would open the chance of seriously lean burning engines with immense potential in terms of thermal efficiency. Interesting times ahead