2014-2020 Formula One 1.6l V6 turbo engine formula

[trinidefender]

but 10-15% surplus air is not needed for full combustion in 2014 F1
IMO

The surplus air is needed, not for full combustion, but to increase the amount of energy recovered from the MGU-H. In a fuel limited system, a lower AFR is needed to run higher airflows, which in turn allows higher boost pressures, giving a larger delta P, which increases MGU-H output.

With partial stratification, the extra air will also provide thermal insulation to the cylinder walls, increasing the ICE's thermal efficiency, increasing the temperature of the exhaust gases, further increasing MGU-H output.

The only problem I see with this is by pumping more air into the cylinder the compressor draws more hp from the turbine meaning less power that the MGU-H can generate. Yes you get more massflow to the turbine but the compressor also has to work harder nullifying this. I can however think of an advantage of running lean to a) ensure complete fuel combustion and b) keep heat in the centre of the combustion chamber reducing thermal losses into the engine block and head. I.e. Increasing thermal efficiency. This also has the added benefit of reducing cooling demands of the ICE.

[Pierce89]

but 10-15% surplus air is not needed for full combustion in 2014 F1
IMO

The surplus air is needed, not for full combustion, but to increase the amount of energy recovered from the MGU-H. In a fuel limited system, a lower AFR is needed to run higher airflows, which in turn allows higher boost pressures, giving a larger delta P, which increases MGU-H output.

With partial stratification, the extra air will also provide thermal insulation to the cylinder walls, increasing the ICE's thermal efficiency, increasing the temperature of the exhaust gases, further increasing MGU-H output.

The only problem I see with this is by pumping more air into the cylinder the compressor draws more hp from the turbine meaning less power that the MGU-H can generate. Yes you get more massflow to the turbine but the compressor also has to work harder nullifying this. I can however think of an advantage of running lean to a) ensure complete fuel combustion and b) keep heat in the centre of the combustion chamber reducing thermal losses into the engine block and head. I.e. Increasing thermal efficiency. This also has the added benefit of reducing cooling demands of the ICE.

I also made the point that the increased flow requirement would not be fully compensated by the greater pressure ratio. There for, it leads to less power recoverable from the turbine.

[Tommy Cookers]

but 10-15% surplus air is not needed for full combustion in 2014 F1
IMO

The surplus air is needed, not for full combustion, but to increase the amount of energy recovered from the MGU-H. In a fuel limited system, a lower AFR is needed to run higher airflows, which in turn allows higher boost pressures, giving a larger delta P, which increases MGU-H output.
With partial stratification, the extra air will also provide thermal insulation to the cylinder walls, increasing the ICE's thermal efficiency, increasing the temperature of the exhaust gases, further increasing MGU-H output.

and ......
higher airflows would not allow higher boost pressure unless 'intercooled' to the same temperature (as the 'base' airflow)
otherwise the CR would have to be lowered
and eg 15% more airflow needs about 30% more supercharger work so requires 30% more cooling
many have seen intercooling as a dominant factor in the car package ?

BTW if people Google V Ganesan Internal Combustion Engines
.... Googling dissociation should also get this book at the right pages
they should find Fig 3.6 (page 115 in my copy) showing real engine BTE benefits (from leaning) fall far short of fuel-air theory
and Prof Ganesan's statement .... 'the maximum efficiency is within the lean zone very near the stoichiometric ratio'

Fig 14.1 shows that CO is already building at 10% lean and eg at 2% lean there is plenty
CO deters dissociation as per Ganesan's Chapter 3 section 5
so if, as many posts say, at 2% lean F1 will not fully combust then there will be plenty of CO and little dissociation

there seems to be always some intermittency (of combustion) that contributes to less than full combustion
this intermittency is worse as mixture strength is reduced even from rich to stoichiometric (says F1 Ferrari tests once linked in this thread)
though (as I have already suggested) DI should help relieve this

[gruntguru]

News flash. This forum now has WORD WRAP!

[rjsa]

=D>

News flash. This forum now has WORD WRAP!

[ringo]

This discussion is not very novel, since we know a team will simply use the engine bench to play around with ratios to get the best result. I'll just say the engine maker will simply go with whatever air to fuel ratio suits their needs from the engine.

[gruntguru]

On the contrary. Never before in the history of F1 (perhaps even the history of motorsport) have all mixtures including full power, been set leaner than stoichiometric.

Additionally the engines are designed for maximum efficiency because that means maximum power. Tuning these engines is totally different to anything previous and the subject should be fascinating to most of us.

[ringo]

Switching gears a bit.
The drivability of the different engines to me is very interesting. I haven't seen much discussion on that even though there is ample evidence that some units, like the ferrari have a poorer drivability.
What's going on with the mercedes power unit, that allows it to behave so well on acceleration out of a corner compared to the renault and ferrari?

[wuzak]

Switching gears a bit.
The drivability of the different engines to me is very interesting. I haven't seen much discussion on that even though there is ample evidence that some units, like the ferrari have a poorer drivability.
What's going on with the mercedes power unit, that allows it to behave so well on acceleration out of a corner compared to the renault and ferrari?

Better software.

Basically it is more sorted.

[piast9]

^^ I doubt if it is only the matter of software. Software is the simplest, cheapest and fastest thing to improve (in my opinion). I don't think that the software engineers at Renault or Ferrari are dumber than their counterparts from Mercedes. That software controls the hardware. Probably the Mercedes hardware is easiest to control.

Renault say that they the big change won't be sooner than 2015. I don't know if they meant only the raw power or the driveability as well. In case of the latter - that would prove that their problems is not only the matter of software.

[FW17]

Switching gears a bit.
The drivability of the different engines to me is very interesting. I haven't seen much discussion on that even though there is ample evidence that some units, like the ferrari have a poorer drivability.
What's going on with the mercedes power unit, that allows it to behave so well on acceleration out of a corner compared to the renault and ferrari?

Merc's secret for drivability control is probably the way the ERS-H works. FIA does not define the power rating of this MGU, Merc probably using a higher rated unit that does a very good job in spooling the turbo and avoid lag.

Other 2 engines are probably having a turbo lag and are using the ERS-K to compensate for this along with ERS-H which causes poor drivability when the turbo kicks in.

[dren]

The chassis has to be thrown in there, too. The Ferrari chassis is weak at the rear making the PU look worse than it is.

[Vortex37]

A few days late, to the specific point.

Regarding stratified charge discussion. Isn't the latest idea, to use a mixed methodology. In the latest Ford DI engines, they use a homogeneous mix at low revs and a pseudo stratified charge at high revs. This appears to be achieved by a variable 'spray pattern'/injector pressure variation. There is also a relatively new form of injector with mechanically variable pattern, that could be in F1 engines.

[Edax]

A few days late, to the specific point.

Regarding stratified charge discussion. Isn't the latest idea, to use a mixed methodology. In the latest Ford DI engines, they use a homogeneous mix at low revs and a pseudo stratified charge at high revs. This appears to be achieved by a variable 'spray pattern'/injector pressure variation. There is also a relatively new form of injector with mechanically variable pattern, that could be in F1 engines.

Isn't that the same as the Volkswagens already have in the FSI engines for the past 10 years or so? It switches from normal to stratified charge depending on power demand.

[irsq4]

A few days late, to the specific point.

Regarding stratified charge discussion. Isn't the latest idea, to use a mixed methodology. In the latest Ford DI engines, they use a homogeneous mix at low revs and a pseudo stratified charge at high revs. This appears to be achieved by a variable 'spray pattern'/injector pressure variation. There is also a relatively new form of injector with mechanically variable pattern, that could be in F1 engines.

Isn't that the same as the Volkswagens already have in the FSI engines for the past 10 years or so? It switches from normal to stratified charge depending on power demand.

Didn't Mitsubishi have that in 1998 in Carisma GDI