2014-2020 Formula One 1.6l V6 turbo engine formula

[godlameroso]

[63l8qrrfy6]

Detonation may not add much meaningful energy to the piston(I disagree, seen detonation launch enough pistons through a cylinder head), it can have a very powerful effect at the turbine.

https://arc.aiaa.org/doi/abs/10.2514/6.2011-577

If you can time the detonations, and the associated turbine acceleration you could increase MGU-H harvesting.

I agree with GG, if you calculate the area under the cylinder pressure curve with detonation it's the same or less than regular combustion - no additional work is being done on the piston over a cycle even though instantaneous loads are higher. Cylinder pressures push the piston the other way, towards the sump. It's the inertia forces that make pistons go through cylinder heads and they are unrelated to detonation.

The paper you linked refers to a gas turbine. In a piston engine all knock induced cylinder pressure oscillations have passed by the time the exhaust valve opens so the turbine can't tell the difference.

[godlameroso]

Depends when you time the exhaust valves.

[saviour stivala]

‘’The paper ‘you linked’ refers to a gas turbine. In a piston engine all knock induced cylinder pressure oscillation have passed by the time the exhaust valve opens, so the turbine can’t tell the difference’’.
The problem, The culprit, is the mixing of lettuce and farts.
The formula one engine turbocharger turbine is a ‘pressure’ turbine and not a pulse turbine since it converts ‘blow-down’ velocity energy in manifold collector into pressure energy. This conversion to pressure energy reflects on the scavenging ability of the cylinders.

[Tommy Cookers]

....The formula one engine turbocharger turbine is a ‘pressure’ turbine and not a pulse turbine since it converts ‘blow-down’ velocity energy in manifold collector into pressure energy. This conversion to pressure energy reflects on the scavenging ability of the cylinders.

doesn't the manifold have equal and 'tuned' length branches ? (to preserve pulsing in the manifold)
so enhancing scavenge to the point of some 'free supercharging' ?
(a pressure turbine wouldn't have such a manifold)

pulses continue beyond the manifold and are reflected above the turbine in phase matching the manifold pulsing ?
pressure lowering of 'negative' reflected pulses is in proportion to pressure raising by turbocharging ?
though yes the turbine activity will weaken these reflections
also there's 'negative' pulses reflected below the turbine from the tailpipe ? - these are weaker as proportionate to ambient

the turbine could be regarded as a 'mixed flow' turbine (as it uses both kinetic 'pulses' and raised mean pressure)
though WGO it has blowdown conditions

[saviour stivala]

The turbine as used in a formula one engine is a pressure turbine since blow-down exhaust gasses velocity energy in manifold collector are converted to pressure energy.

[godlameroso]

Detonation may not add much meaningful energy to the piston(I disagree, seen detonation launch enough pistons through a cylinder head), it can have a very powerful effect at the turbine.

https://arc.aiaa.org/doi/abs/10.2514/6.2011-577

If you can time the detonations, and the associated turbine acceleration you could increase MGU-H harvesting.

I agree with GG, if you calculate the area under the cylinder pressure curve with detonation it's the same or less than regular combustion - no additional work is being done on the piston over a cycle even though instantaneous loads are higher. Cylinder pressures push the piston the other way, towards the sump. It's the inertia forces that make pistons go through cylinder heads and they are unrelated to detonation.

The paper you linked refers to a gas turbine. In a piston engine all knock induced cylinder pressure oscillations have passed by the time the exhaust valve opens so the turbine can't tell the difference.

Passed where, the void?

[hollus]

The turbine as used in a formula one engine is a pressure turbine since blow-down exhaust gasses velocity energy in manifold collector are converted to pressure energy.

Why the need to categorize the turbine with a single word, 100% in a strictly defined and unidimensional mode of action? I like the “mixed flow” description.

[63l8qrrfy6]

Detonation may not add much meaningful energy to the piston(I disagree, seen detonation launch enough pistons through a cylinder head), it can have a very powerful effect at the turbine.

https://arc.aiaa.org/doi/abs/10.2514/6.2011-577

If you can time the detonations, and the associated turbine acceleration you could increase MGU-H harvesting.

I agree with GG, if you calculate the area under the cylinder pressure curve with detonation it's the same or less than regular combustion - no additional work is being done on the piston over a cycle even though instantaneous loads are higher. Cylinder pressures push the piston the other way, towards the sump. It's the inertia forces that make pistons go through cylinder heads and they are unrelated to detonation.

The paper you linked refers to a gas turbine. In a piston engine all knock induced cylinder pressure oscillations have passed by the time the exhaust valve opens so the turbine can't tell the difference.

Passed where, the void?

The amplitudes decay as the volume increases and most of the fuel has been burned. By the time the exhaust valve opens it's all gone.

Not seen one of these before ?


Pre-ignition behaves in a similar fashion:

[saviour stivala]

The turbine as used in a formula one engine is a pressure turbine since blow-down exhaust gasses velocity energy in manifold collector are converted to pressure energy.

Why the need to categorize the turbine with a single word, 100% in a strictly defined and unidimensional mode of action? I like the “mixed flow” description.

I too happen to like the ‘mixed-flow’ type of turbine out of the three types of turbines suitable for exhaust gas turbochargers. (radial-flow, Axial-flow and Mixed-flow). But that doesn’t change the fact that the turbine used in a formula one turbocharger is a pressure turbine and not a blow-down turbine, which was the actual point of contention this ‘turbine type’ discussion.

[Tommy Cookers]

The turbine as used in a formula one engine is a pressure turbine since blow-down exhaust gasses velocity energy in manifold collector are converted to pressure energy.

since the recently-mentioned contention came from me ..... again I contend .....
the 'pulse' velocity energy isn't converted into pressure energy .....
as clearly the manifold design is intended to conserve the pulses - not to convert their kinetic energy into pressure energy
the pulses are eg supersonic not events in the Bernoulli range wherein velocity and pressure can conveniently be interchanged

if pulses are conserved the turbine is powered even if the mean exhaust pressure isn't above ambient pressure
the turbine receives a continuous train of exhaust velocity pulses, one from each cylinder
this is blowdown working of a turbine
blowdown working gives free power - because there is no exhaust 'back pressure'
this is what Wright wrote in the 1950s and (in their Turbo-Compound) proved 15000 times
(though some posts on this site said 'impossible')

a true 'log' manifold will cancel the pulses (by interference etc) - largely converting kinetic energy into heat/pressure energy
some c.2014 F1 manifolds were called 'log' manifolds by posters here - wrongly
interference comes from unequal exhaust path lengths - these manifolds had equal or almost equal path lengths

traditionally it was better/easier to sacrifice the pulses and design for steady raised exhaust pressure - pressure working
turbine design for pressure-only working is presumably somewhat different to design for blowdown-only working
these days as in F1 many exhaust system designs combine both types of working
so-called mixed flow

[saviour stivala]

Yes. The recently-mentioned contention came from you, and believe me, yours is a totally surprising interpretation of what according to Curtiss Wright constitutes a blow-down turbine and a pressure turbine. Surprising. Because I don’t for one minute believe your misinterpretation is intentional, surprising. Because it is straight out of the mouth of an individual that happens to speak the same mother language as those at Curtiss Wight corporation.
From a blow-down turbine, you went on to a pulse-turbine, and now on to a log-manifold.
All that doesn’t change the fact that the present formula one turbocharger turbine is a pressure turbine because exhaust pulses, log-manifolds or not all cylinders of at least one bank of the formula one engine pumps exhaust gases into a collector and into the turbine unless the waste-gate is opened (second path), unlike the blow-down turbine were individual cylinders pumps exhaust gases into the turbine individually through a pipe (jet-stack) of constant cross section.
Just in case we are not quoting from the same technical report. ‘’October 1956. Field engineering department Curtiss Wright Corporation. Wright aeronautical division. Woods-ridge. New Jersey USA. Wright turbo compounding. FACTS ABOUT THE TURBOCOMPOUNDING’’.

[hUirEYExbN]

The turbine as used in a formula one engine is a pressure turbine since blow-down exhaust gasses velocity energy in manifold collector are converted to pressure energy.

since the recently-mentioned contention came from me ..... again I contend .....
the 'pulse' velocity energy isn't converted into pressure energy .....
as clearly the manifold design is intended to conserve the pulses - not to convert their kinetic energy into pressure energy
the pulses are eg supersonic not events in the Bernoulli range wherein velocity and pressure can conveniently be interchanged

if pulses are conserved the turbine is powered even if the mean exhaust pressure isn't above ambient pressure
the turbine receives a continuous train of exhaust velocity pulses, one from each cylinder
this is blowdown working of a turbine
blowdown working gives free power - because there is no exhaust 'back pressure'
this is what Wright wrote in the 1950s and (in their Turbo-Compound) proved 15000 times
(though some posts on this site said 'impossible')

a true 'log' manifold will cancel the pulses (by interference etc) - largely converting kinetic energy into heat/pressure energy
some c.2014 F1 manifolds were called 'log' manifolds by posters here - wrongly
interference comes from unequal exhaust path lengths - these manifolds had equal or almost equal path lengths

traditionally it was better/easier to sacrifice the pulses and design for steady raised exhaust pressure - pressure working
turbine design for pressure-only working is presumably somewhat different to design for blowdown-only working
these days as in F1 many exhaust system designs combine both types of working
so-called mixed flow

What style of exhaust did Mercedes run with in 2014 if it wasn't a log style?

[saviour stivala]

Yes. a blow-down turbine with each individual cylinder constant cross section exhaust pipe connected directly to turbine will produce no back pressure on the exhaust system that will reflect on cylinder scavenging unlike a pressure turbine with individual cylinder constant cross section exhaust pipes all collected into a collector and the collector connected to turbine with a second possible path out through a waste-gate. It is these two different exhaust piping connection systems from cylinder to turbine that makes a turbine a ‘blow-down’ turbine or a ‘pressure’ turbine. Another thing that ‘differentiates’ a ‘blow-down’ turbine from a ‘pressure’ turbine type is the need for a pressure turbine to have a second exhaust gas path out to atmosphere. That is the waste-gate, of which there is no need of on a blow-down turbine. ‘’blow-down turbine = an exhaust ‘back-pressure free turbine’. It is only because the turbine type used by formula one is a pressure turbine that only with waste-gates fully open can the maximum power output possible be extracted from the engine (free-load-mode). And another thing. With waste-gates fully open the exhaust gasses bypassing the turbine, ‘second path-out’ the exhaust gasses are at atmospheric pressure, and with the exhaust gasses at atmospheric pressure no ‘recovery energy’ is possible by the turbine.

[Tommy Cookers]

A Yes. a blow-down turbine with each individual cylinder constant cross section exhaust pipe connected directly to turbine will produce no back pressure .....
B .....different exhaust piping connection systems from cylinder to turbine that makes a turbine a ‘blow-down’ turbine or a ‘pressure’ turbine.

C .....With waste-gates fully open the exhaust gasses bypassing the turbine, ‘second path-out’ the exhaust gasses are at atmospheric pressure, and with the exhaust gasses at atmospheric pressure no ‘recovery energy’ is possible by the turbine.

well
re A .....
Wright joined pipes 2-into-1 before the turbine casing - but (as their paper showed the world) had no 'back pressure'

re B .....
connected pipes do not (unless wrongly designed) produce 'back pressure' - or convert velocity into pressure
2-into-1 and especially F1 3-into-1 behave as individual pipes would - or better
exhaust pulses travel beyond the junction - they aren't cancelled by it

re C .....
F1 has (like most modern turbocharged engines) combined simultaneous pressure and (im)pulse aka kinetic turbine effects
(80s F1 turbo used NA type 'tuned length' ie pulse-action exhaust - this works whether NA or turbo exhaust pressures)

ok a pressure-only design might be better in some types of engine