2014-2020 Formula One 1.6l V6 turbo engine formula

[gruntguru]

Oh but I think it's xactly what Mercedes means, there's simply no way that the ICE alone would be 40+% efficient.

I agree that 40+% is probably total compounded power (ICE + MGUH), but 40+% from the ICE alone is only just around the corner. Toyota are seeing 42% in the lab from the next generation Prius engine - without compounding.

That is not from an Otto cycle. That's from Atkinson cycle.

So what? There is nothing in the rules to stop Mercedes using Atkinson cycle if they find that is more efficient.

No otto cycle is going to produce more than theoretically possible.

Correct. Theoretical Otto efficiency at 10:1 CR is 60% (without compounding)

The compounded power is also misleading. As what the engine makers will do is add the kW produced by the electric motor to the kW produced by the engine then divide it by the kg of fuel used to produce that. zero kg is used to produce the electric power so there will be a big boost to the efficiency figure.

Nonsense. As I have said above, that could be used to produce efficiency above 100%. Such a calculation is quackery and Mercedes would not put their name to it.

[FW17]

Toyota 3.7L NA la mans engine has a compression ration of 17:1

They are also running on spec fuel designed by shell for turbo Porsche 919

[Pierce89]

Toyota 3.7L NA la mans engine has a compression ration of 17:1

They are also running on spec fuel designed by shell for turbo Porsche 919

It wasn't designed for the 919. They both tested multiple fuels and the one used was Porsche's first choice, but Toyota's second or third choice.

[Pierce89]

I agree that 40+% is probably total compounded power (ICE + MGUH), but 40+% from the ICE alone is only just around the corner. Toyota are seeing 42% in the lab from the next generation Prius engine - without compounding.

That is not from an Otto cycle. That's from Atkinson cycle.

So what? There is nothing in the rules to stop Mercedes using Atkinson cycle if they find that is more efficient.

No otto cycle is going to produce more than theoretically possible.

Correct. Theoretical Otto efficiency at 10:1 CR is 60% (without compounding)

The compounded power is also misleading. As what the engine makers will do is add the kW produced by the electric motor to the kW produced by the engine then divide it by the kg of fuel used to produce that. zero kg is used to produce the electric power so there will be a big boost to the efficiency figure.

Nonsense. As I have said above, that could be used to produce efficiency above 100%. Such a calculation is quackery and Mercedes would not put their name to it.

Do you guys not realize that any energy in the ES also came from the fuel?

[xpensive]

Xactly my point Pierce, everything that moves on that car is stemming from the 27.8 g/sec, everything, but this only goes to show how difficult it is to completely understand energy recovery technology as a whole, even for seasoned gurus.

[gruntguru]

Have a think about what you are saying guys. You are suggesting that the efficiency of a powerplant can include energy that has been recycled, stored and added back to temporarily increase the total output. Here is an example.

Lets say that in several years time the rules have changed and the MGUK is limited to 800 kW max. The ICE is producing 300kW and the MGUH is harvesting 100kW - all from a fuel flow allowance of 1000 kW. This equates to a TE of 40%. After a couple of warm up laps charging the battery from the MGUH and the MGUK, the driver does his qualy lap using maximum power from all sources (300kW + 800kW = 1100kW) so according to you the TE is 110% ??????

[xpensive]

Why the average efficiency will be dependent on the average MGU-K power, thus somewhere between 35 and 44%.

[langwadt]

Have a think about what you are saying guys. You are suggesting that the efficiency of a powerplant can include energy that has been recycled, stored and added back to temporarily increase the total output. Here is an example.

Lets say that in several years time the rules have changed and the MGUK is limited to 800 kW max. The ICE is producing 300kW and the MGUH is harvesting 100kW - all from a fuel flow allowance of 1000 kW. This equates to a TE of 40%. After a couple of warm up laps charging the battery from the MGUH and the MGUK, the driver does his qualy lap using maximum power from all sources (300kW + 800kW = 1100kW) so according to you the TE is 110% ??????

it all depends on how you look at it, the TE isn't going to be much more than say 40%
but if you use the fuel flow and TE to estimate the power your number might be much too low

[wuzak]

Do you guys not realize that any energy in the ES also came from the fuel?

The problem is, for efficiency calculations, you do not know how much fuel was burned to generate the stored electricity.

And the energy is not from the 100kg/hr fuel that is being run through the engine at the point in time at which the efficiency is measured/calculated.

[xpensive]

I agree there are a number of unknowns in the estimations, but it at least gives us a vague idea how MHPE came up with 40+%?

[wuzak]

I think it is quite clear that the efficiency will be over 40% in compounded mode.

[gruntguru]

Have a think about what you are saying guys. You are suggesting that the efficiency of a powerplant can include energy that has been recycled, stored and added back to temporarily increase the total output. Here is an example.

Lets say that in several years time the rules have changed and the MGUK is limited to 800 kW max. The ICE is producing 300kW and the MGUH is harvesting 100kW - all from a fuel flow allowance of 1000 kW. This equates to a TE of 40%. After a couple of warm up laps charging the battery from the MGUH and the MGUK, the driver does his qualy lap using maximum power from all sources (300kW + 800kW = 1100kW) so according to you the TE is 110% ??????

it all depends on how you look at it, the TE isn't going to be much more than say 40%
but if you use the fuel flow and TE to estimate the power your number might be much too low

Max power would be based on max output from the MGUK + ICE crankshaft power. Peak ICE crankshaft power is probably greater than 35% of fuel energy ie 0.35 x 1250kW = 437kW (583 hp). MGUK peak = 120kW (160 hp)

Total = 437 + 120 = 557 kW (743 hp)

[OO7]

That is a most resonable estimation; With 46 MJ/kg, 27.8 g/s flow and 35% efficiency you get 450 kW or 600 Hp.

MGU-K is limited to 120 kW or160 Hp, wherever the electricity is coming from, the ES or the MGU-H.

Total 760 Hp means a total efficiency of 44%

That is not a valid application of the word "efficiency and I doubt that Mercedes would quote a number that includes the total power to the MGUK.

The "more than 40%" quoted by Mercedes would include power from the crankshaft and (probably?) power being simultaneously generated by the MGUH under steady state conditions.

600Hp from the ICE is the figure we have seen bandied about for a few years, which I believe is the basic conservative estimate. Marmorini quoted a range with 650Hp being the upper limit (a figure that is greater than what some posters believe to be possible), which he believes is reasonable. So why would an engineer working on the PU, with intimate knowledge of the programme quote an unattainable (according to some here) figure?

xpensive posted of 600Hp from the ICE, with 160Hp from the ES/MGU-H leading to a total of 760Hp and a total efficiency of 44%. Now Andy Cowell of Mercedes HPE during the 'Power-Unit Manufacturers' press conference in China mentioned a 'giant leap' going from NA ICE engines with about 30% thermal efficiency to engines where they are 'all targeting 40%' thermal efficiency and that a 'huge step' a 'huge introduction of new technology both on the internal combustion engine for efficiency and also on the two energy recovery systems...' had been made.
Rob White from Renault later added during the same press conference 'I think Andy was cautious when saying 40%, I think to be competitive you need to be a bit better than 40% already, I think we shouldn't underestimate just how important that is in terms of automotive technology.'

If Andy was referring to 'all targeting 40%' total efficiency, this is 4% lower than the general figure xpensive mentioned and would result in an output less than the 760Hp basic output that has been quoted for a very long time now. So why would Andy mention 40% total efficiency, which results in an output well below the basic figure in the public domain which has been quoted by Renault for instance?

[monsi]

Basically, 40+% is possible for the Diesel process, where the fuel burns under constant pressure, but not a gasoline ICE at 12 kRpm.

Bengt Johansson has achieved 48.5% in the lab using Partially Premixed Combustion (in a Diesel engine but using gasolene and a cycle closer to Otto than Diesel) http://www.sae.org/events/pfl/presentat ... ansson.pdf

The public comments appear to be picking their terms very carefully. I find the slides on p22/3 of the link that gruntguru posted helpful.

[Cold Fussion]

xpensive posted of 600Hp from the ICE, with 160Hp from the ES/MGU-H leading to a total of 760Hp and a total efficiency of 44%.

This doesn't make any sense, unless the mgu-h output was 160 hp.