Edis wrote:Tommy Cookers wrote:2/3 is a falsification
and 2015 fuel is unlike any road fuel and specially made for superior mass-specific energy and efficiency regardless
Since 99% of the fuel must contain compounds normally found in commercial fuels any difference in terms of mass-specific energy would be minimal. The octane rating of the fuel is probably the biggest difference compared to normal commercial fuel, as unlike the previous naturally aspirated engines knock is probably an issue.
Tommy Cookers wrote:the innovation of exhaust recovery was demonstrated by 16000 aircraft (piston) engines in the 1950s (using standard fuel)
recovery typically raised efficiency about 10-15% at sea level
current F1 is about the same (kinetic recovery is inapplicable in real world motoring and its benefit in F1 should be disregarded)
in our road cars we drive at low powers (largely by degrading efficiency) and exhaust recovery is negligible at low mep
yes, we can benefit from engine downsizing, but manufacturers do this already without needing a recovery turbine etc
Kinetic recovery is very much applicable to real world motoring, infact it's a key technology combined with downsizing in all hybrid cars.
Turbocompound isn't new, aside from aircraft it's been used in mass-produced commercial vehicles since the nineties. But electric turbocompound has been quite rare. However, I suspect that this technology can become interesting for car manufacturers within a few years time. On the commercial side it's already being looked at, being worth an estimated 5-10% improvement in fuel efficiency. Since some car manufacturers are already looking at electric supercharging for improving throttle response in downsized turbo engines, a combined turbocharger/generator certainly can't be ruled out. The biggest cost driver for such a technology (just like electric supercharging) is really the higher voltage electric system required to handle the power levels, and if you have paid for that, you want to take as much advantage of that system as possible.
our road fuel is 5% or more Ethanol and so is around 44-45 MJ/kg
current F1 fuel has 5% biofuel, but this is bio-feedstock qualified via 'commercial intent' only, and enables 48 MJ/kg overall
anyway the N/A F1 fuel was designed for combustion speed first and (usually) for volume/specific energy second
I meant to say that kinetic recovery is morally inapplicable in real-world motoring
ie it only has significant value in broad political terms
morally inapplicable meaning that the cost outweighs the (trivial) benefits ie it's not a way to save the world
I have often praised the ingenuity of the current 'PU-concept' rules
but re-definition of heat-engine efficiency allowing energy already delivered to the load to be counted twice as a deliverable ....
is fraudulent and mendacious nonsense
iirc the FIA is claiming (in their unfair comparison with the N/A engine) a 30% improvement in BTE
it should be clear by now whether the claims count or discount KE recovery in their determination of BTE
yes, the F1 race fuel use is reduced significantly by genuine KE recovery (though only reaching 2 MJ/lap at Monza and Montreal ?)
but average road car driving corresponds in KE recovery potential to only a few % of F1's rate or level
sure as anything this (ie the broad, more-electric) technology is interesting (ie significant) to manufacturers
it will help our present manufacturers sell complicated, expensive cars (protectionism and greenwashing combined)
that's what I said 3 years ago, yes, I do feel vindicated by events so far
btw
the mass-produced commercial (compounded) vehicles are all CI not SI ?
and so for good reasons benefit less from exhaust recovery than F1 does
and CI car useage would benefit even less from exhaust recovery
the CI car would benefit more from recovery from coolant (waste) heat - but this is banned in F1 ?