For now.. ..for sure.. ..but if the 'efficiency' mantra/green mask is to be determinedly carried forth..
..C.I... is in the future for F1..
& beyond that.. ..controlled detonation mills.. ..IF 'efficency' - is the real goal..
we know that HCCI is intended for partial power without throttling ie road usegruntguru wrote:Besides, there's nothing to stop them switching off the spark when in HCCI mode.
All you have said is you don't believe that any of these apply to F1, you haven't actually given us any data to back yourself up or any actual reasons. You have, as you were saying "bawling and hollering." People tend to ignore that and prefer to listen to arguments based on fact and data.ringo wrote:I think these novel methods of saving fuel simply don't apply to these engines. I've been bawling and hollering against the way the discussionis going but what can i do. haha. No one seems to care about what happens in a direct injected turbocharged sports car.
None of the engines use "fuel" for cooling. Normal mixture is well lean of stoichiometric. Making the mixture richer (moving it towards stoichiometric) will increase the cylinder temperatures. If the mixture can be made leaner without misfiring or dramatic loss of efficiency, that could be used to "cool the pistons".Jolle wrote:Looking at the fuel usage of the Merc boys, especially HAM, even at the Russian GP he uses very little fuel compared to the rest of the field. In "normal" engine's you would have the fuel a bit rich to cool the engine and prolong the durability.
It looks like that Mercedes have such a good lifespan and heat management that they don't need options like that to be extra gentle on the engine, or do they have so much extra power that they can and save fuel, use a bit more to cool the pistons and be faster and more efficient then anybody else?
More a case of "HCCI has not been successfully demonstrated at other than part load". Researchers would love to extend HCCI to the full range of operating modes. Yes it is unlikely that F1 is employing HCCI.Tommy Cookers wrote:we know that HCCI is intended for partial power without throttling ie road usegruntguru wrote:Besides, there's nothing to stop them switching off the spark when in HCCI mode.
There is no doubt the current engines are rejecting a lot less heat. TE alone tells us that. Say for example an engine makes 800hp and TE is 40%. Heat rejection will be 1200hp. Compare that to previous technology with 800hp and say 30% TE. Total heat rejection will be 1867 hp - over 50% more.trinidefender wrote:Writing this leads me onto another thought. While we debate the effects on stratified injection and all the variations that manufactures are coming up with (debatable if used in F1, probably isn't at this current stage), how much of a reduction in cooling capacity needed would running stratified injection? As in how much heat would the wall of air stop from getting to the cylinder walls....less heat into the cylinder walls not only means more energy going into the crank but also less heat that needs to be removed by the cooling system.
Honda seems to be saying they get a best BTE of 33% fuelled stoichiometrically and a best BTE of 39% fuelled at half stoiSasha wrote:How about Honda's new HLSI?
Lean burn with spark plug ....
Lean limit of A/F31 and found out when in lean mode it's better to have warmer intake(heated fuel or more bypass of intercooler) and combustion temp.
Effiecincy improve by 6.2% over stoichiometric combustion.
This would be true assuming air mass flow levels stay the same. An increase in pressure ratio of the turbocharger and consequently higher air mass flow may can provide the artificial increase in engine capacity needed to realise the lean ratio that they are looking for with the maximum fuel flow. This is assuming of course that the increase in boost pressure and higher mass flow by the turbocharger, and greater friction generated by the additional pressure in the engine doesn't outweigh the benefits.Tommy Cookers wrote:Honda seems to be saying they get a best BTE of 33% fuelled stoichiometrically and a best BTE of 39% fuelled at half stoiSasha wrote:How about Honda's new HLSI?
Lean burn with spark plug ....
Lean limit of A/F31 and found out when in lean mode it's better to have warmer intake(heated fuel or more bypass of intercooler) and combustion temp.
Effiecincy improve by 6.2% over stoichiometric combustion.
doesn't this imply that cutting fuel to 50% of stoi fuel cuts power to 60% of stoi power ? (useful on the road but less useful in F1)
so apparently they would need a much bigger engine fuelled at half stoi to get the same power as an engine fuelled at stoi
bigger in some sense ie capacity, rpm or boost
these values can't be normalised for power (unless eg the stoi engine is throttled and the lean engine unthrottled) ?
again a legitimate comparison for road use but unrepresentative of F1
it would be useful to see the SAE paper
btw they seem unable to eliminate part-time stoi running for NOx catalysis ? true they need less of it (stoi running)