F1technical.net

What we (I) do not know (please correct me if i am wrong):

1. Crankshaft power, which allows lambda calcs
2. Energy content of fuel
3. NOx emission ( a good indicator)
4. Boost or compression or cylinder pressures
5. BSFC (derived or not)

I realise how much of this is commercially or competitively sensitive, but it occurred to me if someone not familiar with the category said how much power do they have no one can really tell them.

According to Mercedes there's the equivalent of 4 average elephants pressing down on each piston, don't know how many elephants they've added since 2016 though.

No one that knows will say, and all we have to go on is estimates.

As far as I can tell for the Mercedes engine(the current benchmark)
1.) 800+ hp from the ICE
2.) 52MJ/kg
3.) I remember saying combustion temperatures can be as high as 2400K so somewhere around 6% oxygen in the exhaust.
4.) Boost ~5bar absolute, Compression 16:1 +-2 points, cylinder pressure ~440bar
5.) no clue.

godlameroso wrote: ↑

10 Mar 2018, 16:30

According to Mercedes there's the equivalent of 4 average elephants pressing down on each piston, don't know how many elephants they've added since 2016 though.

No one that knows will say, and all we have to go on is estimates.

As far as I can tell for the Mercedes engine(the current benchmark)
1.) 800+ hp from the ICE
2.) 52MJ/kg
3.) I remember saying combustion temperatures can be as high as 2400K so somewhere around 6% oxygen in the exhaust.
4.) Boost ~5bar absolute, Compression 16:1 +-2 points, cylinder pressure ~440bar
5.) no clue.

From whence do you get 52MJ/kg?

That would represent a potential power output, at 100% efficiency, of 1450 kw. Mr Cowell typically mentions 1250 (45MJ/kg). He also claims 50% efficiency, which if your numbers are right would allow running at 960hp crank output whilst dribbling a few kw from the H into the ES. I don’t think that happens.

I would think something in the range 45 to 47 is more likely, not that much different from pump fuel.

50% efficiency combined, sure, the ERS boosts efficiency by 6% on it's own. A 42% efficient ICE is still mighty impressive.

730kW combined output seems about right to me.

730kw?

610 kw from the ICE (815 hp). So 120 from the H with enough power from the turbine to drive the compressor at 5 bar? I’m not convinced. What does the ES do?

henry wrote: ↑

10 Mar 2018, 18:21

730kw?

610 kw from the ICE (815 hp). So 120 from the H with enough power from the turbine to drive the compressor at 5 bar? I’m not convinced. What does the ES do?

Provide a load for the MGU-K to induce breaking power at the rear wheels...

henry wrote: ↑

10 Mar 2018, 18:02

godlameroso wrote: ↑

10 Mar 2018, 16:30

According to Mercedes there's the equivalent of 4 average elephants pressing down on each piston, don't know how many elephants they've added since 2016 though.

No one that knows will say, and all we have to go on is estimates.

As far as I can tell for the Mercedes engine(the current benchmark)
1.) 800+ hp from the ICE
2.) 52MJ/kg
3.) I remember saying combustion temperatures can be as high as 2400K so somewhere around 6% oxygen in the exhaust.
4.) Boost ~5bar absolute, Compression 16:1 +-2 points, cylinder pressure ~440bar
5.) no clue.

From whence do you get 52MJ/kg?

That would represent a potential power output, at 100% efficiency, of 1450 kw. Mr Cowell typically mentions 1250 (45MJ/kg). He also claims 50% efficiency, which if your numbers are right would allow running at 960hp crank output whilst dribbling a few kw from the H into the ES. I don’t think that happens.

I would think something in the range 45 to 47 is more likely, not that much different from pump fuel.

Fuel has come a long way since that Cowell figure was mentioned.

Blaze1 wrote: ↑

10 Mar 2018, 18:45

henry wrote: ↑

10 Mar 2018, 18:02

godlameroso wrote: ↑

10 Mar 2018, 16:30

According to Mercedes there's the equivalent of 4 average elephants pressing down on each piston, don't know how many elephants they've added since 2016 though.

No one that knows will say, and all we have to go on is estimates.

As far as I can tell for the Mercedes engine(the current benchmark)
1.) 800+ hp from the ICE
2.) 52MJ/kg
3.) I remember saying combustion temperatures can be as high as 2400K so somewhere around 6% oxygen in the exhaust.
4.) Boost ~5bar absolute, Compression 16:1 +-2 points, cylinder pressure ~440bar
5.) no clue.

From whence do you get 52MJ/kg?

That would represent a potential power output, at 100% efficiency, of 1450 kw. Mr Cowell typically mentions 1250 (45MJ/kg). He also claims 50% efficiency, which if your numbers are right would allow running at 960hp crank output whilst dribbling a few kw from the H into the ES. I don’t think that happens.

I would think something in the range 45 to 47 is more likely, not that much different from pump fuel.

Fuel has come a long way since that Cowell figure was mentioned.

I’m sure the fuels have, we hear regular mentions of a new fuel blend increasing power. However they don’t say whether that is through higher energy content or improved combustion efficiency. My reading is that, given the restrictions on fuel blend, efficiency is more likely than energy density. But I’m far, far, from being an expert.

I also think he mentioned that figure because it’s close to regular pump fuel and so non controversial. But 15% higher energy density seems a stretch.

henry wrote: ↑

10 Mar 2018, 18:21

730kw?

610 kw from the ICE (815 hp). So 120 from the H with enough power from the turbine to drive the compressor at 5 bar? I’m not convinced. What does the ES do?

120 from the ES that harvested energy the previous lap. The reconnaissance and formation laps are more than enough to top off the ES.

It's a combination of both, you develop the fuel in conjunction with your combustion process. All much easier said than done.

godlameroso wrote: ↑

10 Mar 2018, 18:58

henry wrote: ↑

10 Mar 2018, 18:21

730kw?

610 kw from the ICE (815 hp). So 120 from the H with enough power from the turbine to drive the compressor at 5 bar? I’m not convinced. What does the ES do?

120 from the ES that harvested energy the previous lap. The reconnaissance and formation laps are more than enough to top off the ES.

It's a combination of both, you develop the fuel in conjunction with your combustion process. All much easier said than done.

But that puts ICE efficiency, in electric supercharger mode, at 42% which means that if, in self sustain, they achieve 50% the MGU-H would generate 116 kw which is a long way above, arround twice, any estimates I’ve seen So something is inconsistent in the numbers. Either they don’t use 52 MJ/kg or they don’t achieve 50% efficiency.

They don't achieve 50% efficiency, I image they're 1 or 2% away. There are 400kw in the exhaust gases -100 For the compressor leaves 300kw, 27% turbine efficiency which is about par the course. Not impossible, but not easy either.

Let's not forget you can shuttle energy back and forth across both mgus and the ES can also go a variety of ways.

Their defacto race pace mode is probably 690kw sustained for the race distance. The others are probably close in peak power within 20kw at worst, but their sustainable race pace is 15-40kw down.

Of course I could be wrong and Mercedes is using 42MJ/kg fuel and just using black magic to get that kind of oomph.

godlameroso wrote: ↑

10 Mar 2018, 16:30

According to Mercedes there's the equivalent of 4 average elephants pressing down on each piston, don't know how many elephants they've added since 2016 though.

No one that knows will say, and all we have to go on is estimates.

As far as I can tell for the Mercedes engine(the current benchmark)
1.) 800+ hp from the ICE
2.) 52MJ/kg
3.) I remember saying combustion temperatures can be as high as 2400K so somewhere around 6% oxygen in the exhaust.
4.) Boost ~5bar absolute, Compression 16:1 +-2 points, cylinder pressure ~440bar
5.) no clue.

It was claimed on several occasions that the cylinder pressure exceeds 440 bar. I assure you that no aluminium piston can see 300 bar regularly and last for as long as these engines are meant to last. Maybe they can get 400+bar with occasional knock.

Mudflap wrote: ↑

11 Mar 2018, 01:07

godlameroso wrote: ↑

10 Mar 2018, 16:30

According to Mercedes there's the equivalent of 4 average elephants pressing down on each piston, don't know how many elephants they've added since 2016 though.

No one that knows will say, and all we have to go on is estimates.

As far as I can tell for the Mercedes engine(the current benchmark)
1.) 800+ hp from the ICE
2.) 52MJ/kg
3.) I remember saying combustion temperatures can be as high as 2400K so somewhere around 6% oxygen in the exhaust.
4.) Boost ~5bar absolute, Compression 16:1 +-2 points, cylinder pressure ~440bar
5.) no clue.

It was claimed on several occasions that the cylinder pressure exceeds 440 bar. I assure you that no aluminium piston can see 300 bar regularly and last for as long as these engines are meant to last. Maybe they can get 400+bar with occasional knock.

That's what I'm thinking, that they actually allow some detonation to happen. That engine life is determined by how many detonation events have occurred.

Thanks for this fellas (apologies to any ladies there)
It really shows how little we know for sure.
Somewhere I think, there have been some calcs done for horsepower based on weights and GPS time/distance data, anyone know these.
Yes that includes deployment, but I think it helps.

Regarding knock:
If we have the higher BHP figures and the conservative energy fuel (leaving aside knock propensity)(if I can ) the BMEP must be very high and ANY knock is disastrous, end of game stuff, there is no tolerance.
Knock detection may have advanced enough to become predictive, but most is after the fact and that is too late