2014-2020 Formula One 1.6l V6 turbo engine formula

[trinidefender]

You all are willing to accept inaccuracies of over 10% but want to pin down on something as sensitive to making power as A:F?

A +-10% agreement on what AFR is being used in the current engines would be a huge improvement. We have had people arguing for everything from 0.8 to 2.0 ie 1.4 +-43%.

You are not understanding my statement. I am saying that yes 10% difference in A:F is very important. And this is why you cannot willy nilly accept 10% fudged numbers for other things like air temperatures and charge pressure and temperature.
They all affect A:F used.
So I am basically saying that you can't have your cake and eat it. Either you work with complete accuracy or you don't.
Previously you all were fudging up boost temps and pressure. I am saying that you cannot do that and expect to get any useful result.

No such thing as complete accuracy in this world. Only thing is using acceptable errors and tolerances for calculations.

[ringo]

Well 10% is not acceptable by any means when it comes to what we are doing here. It has been said so already about the A:F by gruntguru. So by extension the other aspects must be treated with the same precision.

[gruntguru]

10% is fine when you are trying to estimate what is happening in a competitive and secret technical competition. We can only guess at many of the variables. Ringo, you guessed the AFR is 13.6 - I believe your guess is out by about 50%.

[ringo]

That was not a guess. That is what i DECIDED use.
It was intentionally used to make a direct comparison with the v8 engines. The v8 engine was the control, if the figures were looking similar to the power numbers from the v8 i would know if the thing made sense.
I can easily change the A:F if i please, as it's not guessing, it's calculated.
There aren't any fluff numbers or guesstimates in any of the values I would post in the thread.

[gruntguru]

There aren't any fluff numbers or guesstimates in any of the values I would post in the thread.

So if its not a guess, how did you get it so wrong?

[trinidefender]

That was not a guess. That is what i DECIDED use.
It was intentionally used to make a direct comparison with the v8 engines. The v8 engine was the control, if the figures were looking similar to the power numbers from the v8 i would know if the thing made sense.
I can easily change the A:F if i please, as it's not guessing, it's calculated.
There aren't any fluff numbers or guesstimates in any of the values I would post in the thread.

Ringo the problem with the number you use (13.6:1) is that it only works for airflow limited cars concerning making maximum power. With a fuel flow limited formula like the one we have now maximum power would be at stoichiometric or lean of stoichiometric.

We have already established that airflow is not the limiting factor with boost levels being unlimited and the mgu-h able to spool the turbo if need be. So therefore it means that, as I said. Maximum power will not be created richer than stoichiometric.

If you think differently then I ask you to present your case.

[ringo]

I wont entertain this conversation, as I don't think you all understand what I wrote.
13.6 was used for comparative purposes between new and old engines. I will leave it at that. I wont get into much more.
The other stuff I will not comment on, as those are straw man arguments.

The crux of the discussion is that you cannot ignore or fluff the basis of your calculation and expect that it will give you accurate estimates. Whatever that calculation may be. Be it A:F or power or whatever.
Don't worry about what I use. I can freely change numbers in a heart beat, the point is that if a calculation has 5 steps, you shouldn't fluff any of those 5 steps if you want a meaning solution.

[gruntguru]

Its all guesswork Ringo. At 10,500, my guess is:

MAP = 3.5 bar +- 0.5 (with some help from Renault)
CAT = 70*C +- 25
Lambda = 1.3 +- 0.2
VE = 110% +- 10%
BTE = 42% +- 2% (with some help from MB)

Given those numbers and the uncertainty attached, I have no problems with Reca's rule-of-thumb assumption of 100% VE and ambient CAT. (He actually assumed 1.2kg/m3 ambient air density which is about 21*C at sea level and intercooling back to that temperature.)

[trinidefender]

I wont entertain this conversation, as I don't think you all understand what I wrote.
13.6 was used for comparative purposes between new and old engines. I will leave it at that. I wont get into much more.
The other stuff I will not comment on, as those are straw man arguments.

The crux of the discussion is that you cannot ignore or fluff the basis of your calculation and expect that it will give you accurate estimates. Whatever that calculation may be. Be it A:F or power or whatever.
Don't worry about what I use. I can freely change numbers in a heart beat, the point is that if a calculation has 5 steps, you shouldn't fluff any of those 5 steps if you want a meaning solution.

The original argument was about the efficiency, power and boost pressure use by the ICE. You using a number that you yourself know is wrong (13.6:1) for the 2014 engines is just throwing away any hope of getting a reasonable answer in terms of those three criteria listed. The idea is to increase the accuracy of all the variables that are there and as an end result get the most accurate answer.

You claimed a certain boost pressure is needed to get this much airflow to burn this amount of fuel. That's all well and fine but by using an A:F ratio that is to low means that all your other calculations will be wrong. Why don't you try adjusting your A:F ratio to at least stoichiometric and re-run your calculations and I can almost promise you that your calculations will come out closer to ours.

Or am I asking to much?

[ringo]

The calculation cannot be wrong if it is mathematically sound.
Do you know for a fact that the A:F is not 13.6?

Then in that case, you do not have a case. You are talking as if you have any data from the engine makers.

I know what kind of power I can make using 13.6, and I can compare it to the power being made from a F1 turbo engine from the past and also a V8 engine from the recent past. I use what has evidence of existing. That's the whole point behind 13.6.
I don't see what is so wrong about that. There is a correspondence. In fact if I use 14.7 or whatever the case may be it doesn't give me the right to fluff the other numbers up.

[gruntguru]

Changing the AFR from 13.6 to about 18 will increase the power by about 15%. Tough choice for the F1 engine people. I wonder which way they went?

[trinidefender]

The calculation cannot be wrong if it is mathematically sound.
Do you know for a fact that the A:F is not 13.6?

Then in that case, you do not have a case. You are talking as if you have any data from the engine makers.

I know what kind of power I can make using 13.6, and I can compare it to the power being made from a F1 turbo engine from the past and also a V8 engine from the recent past. I use what has evidence of existing. That's the whole point behind 13.6.
I don't see what is so wrong about that. There is a correspondence. In fact if I use 14.7 or whatever the case may be it doesn't give me the right to fluff the other numbers up.

So basically what you are saying is that for some reason you don't want to burn all the fuel in the combustion chamber? You are going to leave that excess fuel that can be turned into heat and hence pressure in the combustion chamber and power and let it go out of the exhaust?

We have given good reason why stoichiometric values up works. You have given not one reason why you should leave some fuel unburnt in a fuel limited formula.

[gruntguru]

http://ntrs.nasa.gov/archive/nasa/casi. ... 001160.pdf
I am reposting the above link originally posted in the 2 stroke thread by J.A.W. The paper investigates turbo-compound alternatives for helicopter power.

Those who believe that high boost pressures rob unnecessary power from the turbine and reduce thermal efficiency should have a read. For example page 9 states "The best SFC and engine weight balance was found to exist at high compressor pressure ratios (over 10) This is even higher than the Napier Nomad turbo-compound which had a pressure ratio of 6.5 in 1952 and the highest thermal efficiency of any aircraft engine ever produced.

Also of interest is the AFR used.
For the Nomad, ER = 0.65 (Lambda = 1.54)
For the engine proposed in the paper, ER = 0.68 (Lambda = 1.47)
Of course the ICE in both cases is a diesel which means the AFR can be chosen to maximise efficiency since detonation and flame propagation are unaffected by mixture. What it does tell us however is that somewhere around 1.5 is the place to aim for best efficiency provided detonation and flame propagation can be effectively controlled (by optimising DI etc).

On intercooling.
From page 9 An aftercooler was introduced . . . . (various advantages listed) . . . .however a small SFC increase (about 5%) will be incurred. The thermodynamic cycle shown on page 11 shows charge air cooling from 358*C to 224*C. The lesson here is that intercooling does have a penalty in themal efficiency (even the modest cooling used here) so I would expect charge air temperatures in the current F1 engines to be significantly higher than ambient, perhaps even higher than the 70*C used by Honda in the RA168E.

The thermodynamic cycle on page 11 gives a very useful insight into pressure ratios across each element and energy flows. The model does have two turbine stages, one to drive the compressor and one for power recovery but a single stage turbine will do the same job at a given operating point.

[PhilS13]

Just out of curiosity...what is worse for the air : burning 140L @ slightly rich or burning 100L @ very lean ?

[trinidefender]

http://ntrs.nasa.gov/archive/nasa/casi. ... 001160.pdf
I am reposting the above link originally posted in the 2 stroke thread by J.A.W. The paper investigates turbo-compound alternatives for helicopter power.

Those who believe that high boost pressures rob unnecessary power from the turbine and reduce thermal efficiency should have a read. For example page 9 states "The best SFC and engine weight balance was found to exist at high compressor pressure ratios (over 10) This is even higher than the Napier Nomad turbo-compound which had a pressure ratio of 6.5 in 1952 and the highest thermal efficiency of any aircraft engine ever produced.

Also of interest is the AFR used.
For the Nomad, ER = 0.65 (Lambda = 1.54)
For the engine proposed in the paper, ER = 0.68 (Lambda = 1.47)
Of course the ICE in both cases is a diesel which means the AFR can be chosen to maximise efficiency since detonation and flame propagation are unaffected by mixture. What it does tell us however is that somewhere around 1.5 is the place to aim for best efficiency provided detonation and flame propagation can be effectively controlled (by optimising DI etc).

On intercooling.
From page 9 An aftercooler was introduced . . . . (various advantages listed) . . . .however a small SFC increase (about 5%) will be incurred. The thermodynamic cycle shown on page 11 shows charge air cooling from 358*C to 224*C. The lesson here is that intercooling does have a penalty in themal efficiency (even the modest cooling used here) so I would expect charge air temperatures in the current F1 engines to be significantly higher than ambient, perhaps even higher than the 70*C used by Honda in the RA168E.

The thermodynamic cycle on page 11 gives a very useful insight into pressure ratios across each element and energy flows. The model does have two turbine stages, one to drive the compressor and one for power recovery but a single stage turbine will do the same job at a given operating point.

While I do personally believe that current F1 engines run slightly lean of lambda (~1.2), there are a few problems with your post. Firstly it is a diesel piston engine. Diesels never run close to stoichiometric in piston engines because it is very hard to achieve complete combustion with compression ignition.

Combustion stability and ability of achieving complete combustion improvements in recent developments of diesel engines is the reason why modern diesels are getting closer to stoichiometric and making more power. The napier nomad also used a system that used excess air and burned it in a separate combustion chamber before flowing through a turbine that powered the compressor and crankshaft.