we don't seem to know whether the 'thermal efficiency' is ITE or BTE
UK convention was that thermal efficiency is ITE not BTE as thermal efficiency is about the conversion of heat to work
there's a lot more unburnt fuel
Neat how in the future chart, Honda separates the ethanol from the gas in E10 and inject them seperatly.Using the ethanol as a octane booster to run higher CR and knock control during lean burn.
But as Wuzak has pointed out, such discrete ADI is on the verboten list - in F1..
"Well, we knocked the bastard off!"
Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).
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 stoi 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 can't futureproof it wrt part-time stoi running for NOx catalysis - true they need less of it (stoi running) at current standards
The tests were all run at 500kPa NMEP so BMEP and FMEP would also be essentially constant. So moving from the Stoich test to the 30:1 AFR test, they reduced throttling to increase airflow and reduced fuel flow.
we don't seem to know whether the 'thermal efficiency' is ITE or BTE
UK convention was that thermal efficiency is ITE not BTE as thermal efficiency is about the conversion of heat to work
there's a lot more unburnt fuel
Neat how in the future chart, Honda separates the ethanol from the gas in E10 and inject them seperatly.Using the ethanol as a octane booster to run higher CR and knock control during lean burn.
Even when fuel is pre blended ethanol is an octane booster. For instance a 90 octane fuel with ehtanol is really a 86 octane boosted by ethanol to 90 for arguement's sake. So that's nothing novel. It would be interesting to know where they inject separately. Maybe they can control octane with that setup?
Electrically controlled waste gates, and injector pattern among other things are interesting. Most things seem related to emissions though, but interesting nonetheless.
Electrically controlled waste gates, and injector pattern among other things are interesting. Most things seem related to emissions though, but interesting nonetheless.
Perhaps Ringo, you could point out the relevant specific technical relationship points therein - to F1, current or future..
..since you present as fixated by such a notion - even when it seems unsupported - by the evidence base..
"Well, we knocked the bastard off!"
Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).
Electrically controlled waste gates, and injector pattern among other things are interesting. Most things seem related to emissions though, but interesting nonetheless.
Perhaps Ringo, you could point out the relevant specific technical relationship points therein - to F1, current or future..
..since you present as fixated by such a notion - even when it seems unsupported - by the evidence base..
Let's give it a chance. I just started reading the 120 page report and already noticed one thing. This BMW engine that is shown in the report uses a 6 cylinder ICE with two turbochargers in parallel. Meaning 3 cylinders are connected to each turbocharger turbine. For a turbine to harvest blowdown power (power taken from the kinetic energy of the exhaust pulses) then no more than 3 cylinders can be on each turbine inlet to stop exhaust pulse overlap. I wonder if BMW are using this method in their turbines.
Sasha wrote:Neat how in the future chart, Honda separates the ethanol from the gas in E10 and inject them seperatly.Using the ethanol as a octane booster to run higher CR and knock control during lean burn.
Even when fuel is pre blended ethanol is an octane booster. For instance a 90 octane fuel with ehtanol is really a 86 octane boosted by ethanol to 90 for arguement's sake. So that's nothing novel. It would be interesting to know where they inject separately. Maybe they can control octane with that setup?
They propose to seperate it so that low octane fuel can be used for light load operation, saving the ethanol for full load operation when it is needed. eg E0 86 octane at light load progressing up to E50 100 octane at full load.
trinidefender wrote:Let's give it a chance. I just started reading the 120 page report and already noticed one thing. This BMW engine that is shown in the report uses a 6 cylinder ICE with two turbochargers in parallel. Meaning 3 cylinders are connected to each turbocharger turbine. For a turbine to harvest blowdown power (power taken from the kinetic energy of the exhaust pulses) then no more than 3 cylinders can be on each turbine inlet to stop exhaust pulse overlap. I wonder if BMW are using this method in their turbines.
No doubt they are utilising blowdown energy although a turbo with divided exhaust housing will also achieve this on a 6 cylinder. One added benefit of 2 smaller turbos is lower effective inertia - quicker response than a large single. Another is reduced header plumbing and consequential heat loss and thermal mass.
Downside is lower compressor and turbine efficiency .
Indeed, & BMW, AFAIR, retain their favour for the smooth, if long.. ..inline-6 layout, so twin turbos are a natural fit..
However F1 mills certainly sound like they utilize the same 120`firing order..
& that ADI usage for high load/high-test fuel substitute/augmentation is old school S.O.P...
BMW used an ADI petrol injection set-up - into the compressor eye of their 801 radial aero-moteur, ~70 y/ago
"Well, we knocked the bastard off!"
Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).
Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).
IMO they wouldn't need or use a balance shaft
the balance is better with this 90 deg than the often used 60 or 65 or 80 deg (F1 and some older road V6s)
balancewise 90 deg is better than 120 even (though 120 is better than 90 in performance aspects)
90 deg with a single turbine, the 2 bank's (equally-spaced) exhaust pulses become unequal when combined in a symmetrical system
if asymmetrical, eg left secondary about 20 cm longer than right then combined pulse spacing is ideal (around max rpm only)
this was used in early (single turbo V6s eg F1 Renault) and seems to be used today in F1
it is still useful with double-entry turbos (and vice-versa) ? - it costs nothing
Last edited by Tommy Cookers on 23 Oct 2014, 18:47, edited 1 time in total.
we don't seem to know whether the 'thermal efficiency' is ITE or BTE
UK convention was that thermal efficiency is ITE not BTE as thermal efficiency is about the conversion of heat to work
there's a lot more unburnt fuel
Neat how in the future chart, Honda separates the ethanol from the gas in E10 and inject them seperatly.Using the ethanol as a octane booster to run higher CR and knock control during lean burn.
Even when fuel is pre blended ethanol is an octane booster. For instance a 90 octane fuel with ehtanol is really a 86 octane boosted by ethanol to 90 for arguement's sake. So that's nothing novel. It would be interesting to know where they inject separately. Maybe they can control octane with that setup?
Ethanol by its self is 113 octane.So you take the ethanol from the 90 octane E10 and you direct inject when you need the octane(knock control-octane booster).Kinda like what they did with WW2 airplane engines(Germany-MW-50 methanol/water).
If people are interested in technical data on BMW's road engines, you will often find the best public data in MotorenTechnischeZeitschrift (MTZ). Not F1, though, nor state of the art, really. The engines are already public domain and represents what they were developing a few years back.
Back to F1 2014 engine. I thought it was interesting that both Andy Cowell and Rob White have both recently stated in RET that the only reason 40% efficiency is being quoted is because all front runners are already above this level (or words to that effect) ...
