F1technical.net

inox wrote:http://www.formula1benzing.eu/

Enrico Benzing has been writing recently a lot about teams constantly exceeding the fuel flow limits. From what I understand from his estimations, the ICE power figures have risen by 200 hp since the beginning of 2014 and the increase in power is only made possible because engine manufacturers are able to circumvent the 100 kg/h rule. He says that increasing fuel flow by 1 kg/h brings 10 extra hp and appears to estimate that maximum fuel rate in qualifying is already approaching 120kg/h. What do you think, can they really reach this high fuel flow rates without being caught?

At least I have always suspected that Mercedes is able to feed a lot more fuel in their qualifying mode. Or are there other ways to get out significantly more power for short periods than in normal race conditions?

That just amounts to Enrico not "believing" the efficiency numbers required to achieve circa 1000bhp with 100kg/hr fuel, there's no evidence or substantiation, he just doesn't "believe" it.

mrluke wrote:

inox wrote:http://www.formula1benzing.eu/

Enrico Benzing has been writing recently a lot about teams constantly exceeding the fuel flow limits. From what I understand from his estimations, the ICE power figures have risen by 200 hp since the beginning of 2014 and the increase in power is only made possible because engine manufacturers are able to circumvent the 100 kg/h rule. He says that increasing fuel flow by 1 kg/h brings 10 extra hp and appears to estimate that maximum fuel rate in qualifying is already approaching 120kg/h. What do you think, can they really reach this high fuel flow rates without being caught?

At least I have always suspected that Mercedes is able to feed a lot more fuel in their qualifying mode. Or are there other ways to get out significantly more power for short periods than in normal race conditions?

That just amounts to Enrico not "believing" the efficiency numbers required to achieve circa 1000bhp with 100kg/hr fuel, there's no evidence or substantiation, he just doesn't "believe" it.

Which are your best points that substantiates the 1k bhp?

1000 BHP from the ICE alone with the 100kg/hr doesn't add up.

Taking some basic thermodynamics:
Energy Density of Gasoline ~ 46MJ/kg
Fuel Flow 100kh/hr = 0.0277 kg/s
Energy Density / second = 46x0.0277 = 1.274 MJ/s = 1.274 MW = 1274 KW
Theroretical Max Efficency (carnot cycle approximation) = 64%
Theroretical Max Efficiency < 0.64*1274 = 815.488 KW
KW to BHP = 1.34 = 815*1.34 = 1092 BHP

So using a perfectly ideal Carnot cycle 1000 BHP is theoretically attainable, ignoring any losses.

Typically an Otto cycle (ICE engine) is said to have a thermal efficiency of 38%. Reports from 2015 had the Mercedes (assuming ICE) thermal efficiency at 48.5% which is staggering considering the status quo.

At a reported 48.5% * 1274*0.485*1.34 = 827 BHP

The only variables to the above would be the Energy Density of the Fuel, this is taken at the higher end of what should be theoretically possible. However, given HCCI and TJI ignition the fuels could possibly be as high as 50MJ/kg giving 900 BHP.

That's power in self sustaining mode, now add in the ERS. In qualifying these heavier cars(100+kg) have higher top speeds than any V10 car.

godlameroso wrote:That's power in self sustaining mode, now add in the ERS. In qualifying these heavier cars(100+kg) have higher top speeds than any V10 car.

True but they also have at least 2 more gear ratios to play with which helps top speed.

Ground contact drag and Aero Drag will have significantly increased with the larger cars also, I would be very surprised to see a significant increase in top speed this year.

djos wrote:

godlameroso wrote:That's power in self sustaining mode, now add in the ERS. In qualifying these heavier cars(100+kg) have higher top speeds than any V10 car.

True but they also have at least 2 more gear ratios to play with which helps top speed.

On the flip side, they can't change these ratios race to race

Robbobnob wrote:1000 BHP from the ICE alone with the 100kg/hr doesn't add up.

Taking some basic thermodynamics:
Energy Density of Gasoline ~ 46MJ/kg
Fuel Flow 100kh/hr = 0.0277 kg/s
Energy Density / second = 46x0.0277 = 1.274 MJ/s = 1.274 MW = 1274 KW
Theroretical Max Efficency (carnot cycle approximation) = 64%
Theroretical Max Efficiency < 0.64*1274 = 815.488 KW
KW to BHP = 1.34 = 815*1.34 = 1092 BHP

So using a perfectly ideal Carnot cycle 1000 BHP is theoretically attainable, ignoring any losses.

Typically an Otto cycle (ICE engine) is said to have a thermal efficiency of 38%. Reports from 2015 had the Mercedes (assuming ICE) thermal efficiency at 48.5% which is staggering considering the status quo.

At a reported 48.5% * 1274*0.485*1.34 = 827 BHP

The only variables to the above would be the Energy Density of the Fuel, this is taken at the higher end of what should be theoretically possible. However, given HCCI and TJI ignition the fuels could possibly be as high as 50MJ/kg giving 900 BHP.

Yes for total amount of possible HP the Energy density is only variable.
But for possible HP engine can produce from that burned fuel there is more variables - i can name some.
How much do You lose in frction, How much fuel of what You inject You actually burn. How much You can recover in exaust (its not Otto Cycle anymore). And typical Otto cycle efficiency is closer to 70% actually.
Because of factors - some of which i mentioned You do not get that much on typical engine thats why some think its not possible. Fortunately F1 does not use typical engines anymore.
P.S. Lot of those variables and factors are discussed in this very same thread starting a few years back.

djos wrote:

godlameroso wrote:That's power in self sustaining mode, now add in the ERS. In qualifying these heavier cars(100+kg) have higher top speeds than any V10 car.

True but they also have at least 2 more gear ratios to play with which helps top speed.

Wut? They had 7 gears and now they have 8?

djos wrote:

godlameroso wrote:That's power in self sustaining mode, now add in the ERS. In qualifying these heavier cars(100+kg) have higher top speeds than any V10 car.

True but they also have at least 2 more gear ratios to play with which helps top speed.

And DRS!!

Juzh wrote:

djos wrote:

godlameroso wrote:That's power in self sustaining mode, now add in the ERS. In qualifying these heavier cars(100+kg) have higher top speeds than any V10 car.

True but they also have at least 2 more gear ratios to play with which helps top speed.

Wut? They had 7 gears and now they have 8?

They're comparing to v10s with six speed boxes. Seven speed boxes were only on some v10s late in that cycle, but the vast majority of v10 running was with six speeds. When the v8s came out, everyone went with 7.

But those 6 gears were tailored to the circuit

Are the current engines faster than V10 without DRS? NO

V10 with DRS would have hit 380 kph @ Monza

Pierce89 wrote:

Juzh wrote:

djos wrote:
True but they also have at least 2 more gear ratios to play with which helps top speed.

Wut? They had 7 gears and now they have 8?

They're comparing to v10s with six speed boxes. Seven speed boxes were only on some v10s late in that cycle, but the vast majority of v10 running was with six speeds. When the v8s came out, everyone went with 7.

V10 was in use from 1995-2005. I know 7 speed gearboxes were already in use at least as early as 2000, perhaps even before that. But when we're comparing current turbos we're obviously comparing them to 2004-2005 V10s.

kasio wrote:

Robbobnob wrote:1000 BHP from the ICE alone with the 100kg/hr doesn't add up.

Taking some basic thermodynamics:
Energy Density of Gasoline ~ 46MJ/kg
Fuel Flow 100kh/hr = 0.0277 kg/s
Energy Density / second = 46x0.0277 = 1.274 MJ/s = 1.274 MW = 1274 KW
Theroretical Max Efficency (carnot cycle approximation) = 64%
Theroretical Max Efficiency < 0.64*1274 = 815.488 KW
KW to BHP = 1.34 = 815*1.34 = 1092 BHP

So using a perfectly ideal Carnot cycle 1000 BHP is theoretically attainable, ignoring any losses.

Typically an Otto cycle (ICE engine) is said to have a thermal efficiency of 38%. Reports from 2015 had the Mercedes (assuming ICE) thermal efficiency at 48.5% which is staggering considering the status quo.

At a reported 48.5% * 1274*0.485*1.34 = 827 BHP

The only variables to the above would be the Energy Density of the Fuel, this is taken at the higher end of what should be theoretically possible. However, given HCCI and TJI ignition the fuels could possibly be as high as 50MJ/kg giving 900 BHP.

Yes for total amount of possible HP the Energy density is only variable.
But for possible HP engine can produce from that burned fuel there is more variables - i can name some.
How much do You lose in frction, How much fuel of what You inject You actually burn. How much You can recover in exaust (its not Otto Cycle anymore). And typical Otto cycle efficiency is closer to 70% actually.
Because of factors - some of which i mentioned You do not get that much on typical engine thats why some think its not possible. Fortunately F1 does not use typical engines anymore.
P.S. Lot of those variables and factors are discussed in this very same thread starting a few years back.

All the above variables you have mentioned are accounted for in the overall thermal efficiency. My calculation was only an assumption based on the ICE, not taking into account the hybrid drivetrain including the compressor and turbine as the electrical control system complicates the energy calculations beyond a simple PV diagram analysis.

An Ideal Carnot Cycle can have a thermal efficiency close to 0.7 however, 48.5% is the highest given efficiency figure publicly given thus far by a formula 1 team.

Cowell added that the current V6 power units are now producing more power than the V10 engines, which were last used in F1 in 2005 and hold most of the lap records at circuits still on the calendar from that era, and are almost twice as efficient.
He said: “If you look at the total power that we’ve got today and compare it with the V10, and the last few races of the V10 era, we have more power than we had at the end of the V10 era.
“If you look at the fuel flow rate of the V10 era, it was over 190kgs an hour, 194kgs an hour, and today we’re at 100kgs an hour. [It’s] the same power, [with] about half the fuel flow rate, which is a phenomenal change in terms of efficiency of the power unit, as we now call it.”

We have gone over and over these same arguments since 2014.

The V6Ts have a widely accepted peak BHP of between 900 and 1,000bhp.

Just because your road car has an efficiency of circa 40% does not mean that the F1 teams have the same constraints.

The only way the V10s were getting a higher top speed than the current V6Ts would be by running less total drag. That is the only possibility.