gruntguru wrote: ↑
Sun Oct 01, 2017 5:11 am
johnny comelately wrote: ↑
Sat Sep 30, 2017 8:05 am
Anyway, the point being is that the subject is higher burn fraction as a factor in the higher efficiency F1 engines, maybe even 98% - 99%.
In order to do that the boundary layer has to be minuscule and that is possible with coatings.
Agree on the burn fraction - but that is burn-fraction of fuel - not air. There is a lot of excess air in current F1 engines - approx 100% so the boundary layer does not have to be minuscule provided there is no fuel in it.
I'm not quite with you there.
If 'burn fraction' is the wrong terminology i apologise for that.
My understanding it is the AF mix.
My premise is the amount of burn of the AF mix as it can contribute to the push.
This being done by a relatively complete burn contained in an environment that can handle it: coated chamber and piston (or carbon piston), flame ignited.
Essentially to get rid of quench induced boundary layer.
This is the fuels maximum contribution to the 50% thermal efficiency (which is such a complex total measurement)
One of the benefits is the extra heat available to drive the turbo and ancillary.