2014-2020 Formula One 1.6l V6 turbo engine formula

[timbo]

For instance, car engines have been using aluminium alloys in pistons for a very long time and the temperature inside the combustion chmaber is much more than 300C.

Peak temperatures are definitely higher than 300C, but the average temperature may be below that.
After all it is a problem of how much heat is generated and how much is dissipated. If there's more heat generated and the dissipation stays same the temperature of the piston may rise.

[Tommy Cookers]

the piston in an SI engine has 2 main jobs

be light - as the piston is most of the reciprocating mass being lighter gives higher power by allowing higher rpm
conduct heat well - the better it conducts heat the lower the crown temp, allowing higher CR and/or massflow via supercharging

that's why when reasonably strong Al alloys emerged c.WW1 engines were transformed as Al displaced steel almost overnight
then Magnesium alloy was sometimes used, eg in the dominant GP Delage in the 20s ?
Al and Mg having have much better thermal conductivity than steel as well as being much lighter (Young's modulus is anyway irrelevant)
the Al or Mg piston can and will be thicker than a steel one, further benefiting the conduction (from piston crown to cylinder)

today we quite often have oil cooling of pistons in even road SI engines
useable CR and/or massflow was at one time also greatly limited by valve cooling
until Heron took the UK 'sodium-cooled' valve in the 1920.to the USA , where it was developed to become universal in aero engines

2014 F1 seems arranged (by fuel capping at 10500 rpm) to allow the weight of steel pistons
but it's a surprise to me that they are needed (though the Simon article mentioned this here over a year ago)

[Tommy Cookers]

but the following lines make it impossible to have a fuel with hing RON numbers

19.1.2 The detailed requirements of this Article are intended to ensure the use of fuels that are
composed of compounds normally found in commercial fuels and to prohibit the use of
specific power-boosting chemical compounds.

19.1.3 Any petrol, which appears to have been formulated in order to subvert the purpose of this
regulation, will be deemed to be outside it.

each pump of petrol/gasoline contains around 800 substances
in principle not the same 800 as in the next pump down the road
the current total spread ('menu') is about 1500 substance worldwide (25000 substances have been found in crude oil worldwide)
the rules cannot greatly limit and do not greatly limit changes in the proportions used (yes' I have looked at the rules !)
(economics determines the proportions in the semi-accidental blend that is road fuel)
because they can only classify the substances into broad families ie chemistry type classifications
members of the same family can and do have hugely different Octane nos and different calorific values
eg the trivial example, we all know IsoOctane has an Octane no of 100 and normal Heptane has an Octane no of 0
IIRC what is called by chemists normal Octane has an Octane no of -12 (and is of course chemically identical to IsoOctane)
some on the menu of 1500 substances have not ever had their Octane no determined
the FIA would need to check all 1500 even to begin to write a rulebook to control RON by chemistry

the FIA has since 1958 continually tried to limit detonation resistance by declaring a limit of Octane number eg 102 RON
since when the fuels all appear to have complied (partly because 102 RON test means nothing at F1 rpm or even modern road rpm)

now the same FIA seems to have thrown away that part of the rule book
I don't think anyone should believe that fuel will remain 102 RON or even 102 combined RON and MON
it will be 'off the clock', as the FIA seems to have taken away the clock

btw
engine performance will be limited by fuelling, metered to 100 kg/hr and 100 kg total
no-one will be counting as fuelling the burning of 1 or 2 or 3 or ? kg of 'oil' ??

[rjsa]

That's a tough proposition: counting on burning oil in engines expected to last reeeeeally long.

[langwadt]

That's a tough proposition: counting on burning oil in engines expected to last reeeeeally long.

5.12 Engine intake air :
Other than engine sump breather gases, exhaust gas recirculation, and fuel for the normal
purpose of combustion in the engine, the spraying of any substance into the engine intake air
is forbidden.

So I guess if you had enough oil capacity to spare you could use engine oil as additional fuel via the sump breather

[rich1701]

Ferrari testing their V6 f1 Turbo in the back of a La Ferrari allegedly. Apologies if this has been posted already. Sounds really good though I think at low revs anyway. Pleasantly surprised

http://www.autoblog.com/2013/12/02/ferr ... -f1-video/

[ringo]

Sounds sweet near the end. It sounds like a turbo charged race engine for sure, but not sure if it's for F1.

[ringo]

Is steel pistons necessary?? I thought they would just use some sort of aluminium alloy with a ceramic heat barrier coating on top and low friction coatings on the skirts.

And Mahle delivers pistons to Mercedes right??

I think when it comes to longevity and overall strength, steel is the best choice.
Aluminum will always be lighter, however it's specific modulus is not as high as steel ( stiffness per mass of material).
Another way of looking at it is the young's modulus per density. Steel is about 3 times greater in that regard.

Young's modulus of Aluminium is ~70GPa. Density ~2700kg/m^3
Young's modulus of Steel is ~200GPa. Density ~7800kg/m^3

70/2700 = 0.02592
200/7800 = 0.02564

In other words, about the same.

There goes that argument. Basically for the same weight you can have more material with aluminium, which can help with stiffness (where section properties play a big part).

You could talk in terms of tensile strength, but there is a wide variety of grades of steel and aluminium, and thus a wide variety in tensile strengths.

my mistake, the density is 3 times greater, but the specific stifness is roughly the same. the slight advantage going to aluminum. was a bit tired when i posted that.
But the point stands that for longevity steel is the best bet. Aluminum doesn't have an endurance limit like steel.

[FrukostScones]

AMuS Interview with Pat Fry on 2014 car development as well as the F138. Very very interesting read.

http://www.auto-motor-und-sport.de/form ... 43954.html

AMUS: Can the engines next year compensate for aero deficts?

Fry:......
I believe that there will not a big power/performance difference between the engines. Maybe in the race, when the fuel consumptiopn dictates the performance. (so Ferrari has the alleged efficiency deficit?)

AMUS: Do you see many loopholes in the regs?
Fry: The aerodynamic regs are pretty clear, regarding the powertrain I see the possibilty to interpret certain things differently.

[xpensive]

...
my mistake, the density is 3 times greater, but the specific stifness is roughly the same. the slight advantage going to aluminum. was a bit tired when i posted that.
But the point stands that for longevity steel is the best bet. Aluminum doesn't have an endurance limit like steel.

Please identify "longevity" and "endurance limit", also xplain why Aluminium should be inferior to steel in those respects?

[ringo]

when you dynamically load a part, it goes through cycling. This can be bending a paper clip back and forth or a crank shaft rotating by the force of combustion. if you take a marker and mark a point on the crank journal, you can imagaing that when the point moves from 0 to 180 degrees it goes from tension to compression since it is in a different location but the bearing stresses are applied the same way.
The part will eventually break after a certain number of cycles with a certain amount of force/stress applied to it.

A paper clip bending back and forth will brake in rouhgly 25 bends; try it. It's the alternating of compression and tension that is responsible.
This is called alternating stress, or cyclic stress. The repetitive compressive and tensile loading on a part.

However it is observed that if you reduce the average alternating load you can make the part do more cycles without breaking.
There are materials like steel that if you reduce the stress to a certain point the part can be stressed indefinitely without breaking. This value of stress is called the endurance limit and this occurs when the steel part can do 10 x 10^8 cycles.
or 100 million rotations.


This is shown on the S-N curve abouve, (the stress to cycles curve) and is really the average altenating stress.
For the steel curve you notice that as the stress goes down, the cycles before failure increase, indicating increased life, but there is a point where the cycles continue to increase indefinitely as you stress it (you go across the graph at a value of stress of say 20ksi it doesn't cut the curve) . It is considered to have infinite life; it won't break.
What you notice is that aluminum doesn't have an endurance limit. So no matter how you want to tailor the loads to reduce the stress on the part, it will eventually break at some time after a certain number of cycles (any value of stress will cut the curve at a certain # of cycles).
All aluminum parts will break, and as an example this is why cars with aluminum control arms need those replaced after years of on track abuse. They have stress cracks on them. For steel control arms, the part is more likely stressed within the endurance limit and gives infinite life, so you don't worry about a part failure.
The endurance limit principle is also one of the considerations used to predict how much miles an engine can do as well.

So i think steel pistons is a very wise move in ensuring that you can design them at a certain level and not worry about stress cracks.
On the other hand you can agressively desing a steel part nice small and light and make it fail in 10000 cycles when you know you only want to get 9000 cycles out of it. I think this is what they did in the past with those qualifying engines.

[xpensive]

You mean Wöhler-diagrams and their "fatigue limit", but that has been investigated well enough for Aluminium to be used and trusted in both aircraft- and bridge-structures, why I doubt if it would be a decisive factor in engine-components.

More important is the strength of a 7000-series Alu-Alloy, I have designed a 7075 M24-bolt with 70% of the A4-bolt's strength.

[Tommy Cookers]

@ ringo
so you think that the billions of Al alloy pistons are wrong ?
(and the millions of British motorcycle Al alloy conrods that lasted just fine, even in racing)
even British designers knew that steel designs would tend to a longer fatigue life - so what when the Al design has enough life ?

your paper clip example is the usual 'physics teacher' nonsense
because fatigue is all about behaviour within the elastic range

a steel piston would be used when the temperature is more than Al alloy could handle
ie a temperature at which its elastic limit stress would be so lowered the engine couldn't stand the rpm or even combustion loads
your S-N curves are for normal temperatures, not elevated temperatures

[xpensive]

@ ringo
...
your paper clip example is the usual 'physics teacher' nonsense
because fatigue is all about behaviour within the elastic range
...

I actually missed that one TC, you're correct of course, the paperclip xample is not relevant, has nothing to do with fatigue.

[Holm86]

Is temperature really that big of an issue with AL pistons?? With modern thermal barrier coatings to the piston crown.

The piston wont absorb that much of the combustion heat then. But that would probably increase the exhaust temperature instead then.