Honda Power Unit Hardware & Software

[gruntguru]

An even-firing three cylinder in-line can only fire end to end and the banks of an F1 engine are even-fire to maintain separation of blowdown pulses without ridiculously complex headers.

Looking at just one bank of three cylinders, would this take place over 2 revolutions, as per a normal 3 cylinder engine?

Whereas the theoretical 1-2-3-4-5-6 firing order would have one bank fire in 1 revolution and the other bank fire in the second revolution.

Yes. An even firing IL3 will have spacings of 240*-240*-240*. The alternative would be 120*-120*-480*

[PlatinumZealot]

How much energy is transferred to the turbine via gas kinematics, and how much is it due to the difference in pressure pre and post turbine?

You forgot temperature too. Turbine works with energy of the gas. Temperature, pressure and velocity.
You can bring velocity down to zero and find the stagnation pressure and temperarure and find the enthalpy. If my school memory is still intact.

[godlameroso]

I guess it's a bit chicken and the egg type question

[Brian Coat]

I guess it's a bit chicken and the egg type question

It's a thermodynamics question, isn't it.

As PZ points out, its enthalpy change that defines the power output.

For a simplified steady-flow, adiabatic, etc. etc. case ...

P= mCp(Tin-Tout) x eff.

[henry]

I assume the higher the proportion of blow down energy recovery the more useful it would be in the wastegate open mode, reducing the amount of work the MGU-H needs to do.

[SameSame]

How much energy is transferred to the turbine via gas kinematics, and how much is it due to the difference in pressure pre and post turbine?

You forgot temperature too. Turbine works with energy of the gas. Temperature, pressure and velocity.
You can bring velocity down to zero and find the stagnation pressure and temperarure and find the enthalpy. If my school memory is still intact.

For an ideal gas, enthalpy is a function of temperature only. For a non-ideal gas, you could use an equation of state to determine the enthalpy by knowing the temperature and pressure at the required states (and using appropriate deviation factors obtained from the pressure and temperature ratios). Seeing as enthalpy is h = u + Pv, you could determine the internal energy at the inlet and outlet and the enthalpy at the inlet and outlet and from there you could determine the relative contribution of each term.

Edit:
h = enthalpy
u = internal energy
P = pressure
v = specific volume

[Tommy Cookers]

[quote="gruntguru"]An even-firing three cylinder in-line can only fire end to end and the banks of an F1 engine are even-fire to maintain separation of blowdown pulses without ridiculously complex headers.
[quote]There are only two possible firing orders (as observed in my second post). All the others are variations resulting from different choices for cylinder numbering and rotation.[quote]
NOTE TO SELF
Bank A 1 2 3 1 2 3 1 2 3
Bank B 1 2 3 1 2 3 1 2 3
(we might call this 1 2 3 4 5 6)
Bank A 1 2 3 1 2 3 1 2 3
Bank B 1 3 2 1 3 2 1 3 2
(we might call this 1 2 3 6 5 4)
these are two different orders ie as far as the disposition in space and time of crankshaft moments etc is concerned
- but yes the second would not produce a good pulse train -
(this might be relevant to the 62-77 Buick case)

[Tommy Cookers]

How much energy is transferred to the turbine via gas kinematics, and how much is it due to the difference in pressure pre and post turbine?

Good question. If you combine more than 3 even-fire cylinders or exhaust into a common plenum pre-turbine, blowdown energy is lost ie zero blowdown energy and 100% reaction energy.
With careful design to maximise blowdown energy recovery, the Wright Turbo-compound - recovering blowdown energy only (no increase in back pressure) was able to recover an additional 14% on top of crankshaft power at cruise and 24% at take off. (before gear losses). This represents the other end of the scale - 100% blowdown and 0% reaction energy.

the Wright TC data all seems early 1950s ie from the 6.7 CR version ie no data from the later 7.2 CR version that was in most of the airliners
(also the compounded Merlin project also used standard CR c.7)

presumably recovery would have been less with eg .........
conceptual 11 CR (ie optimal for endurance cruise, no takeoff)
or say 18 as in F1 ?

usual TC net recovery data seems to be additional 6% in (low boost, low power, max endurance, patrol) cruise and additional 18% at takeoff
data on usual airline or transport cruise would be interesting

a good bit of info ie on the effects of a rich mixture with the 'Wright' kind of fuel .....
http://www.grandprixengines.co.uk/Note_58-2.pdf
someone told me (of what simply could be called aborting a landing due to inability to find the runway) with Hudsons in WW2 Coastal Command ....
that their manual (compiled by BOAC 'experts') said to use 'auto rich' for the 'go-round'
this instruction was cancelled some time after the Navy recovered bodies eg from 3 planes literally piled on top of each other (on the seabed)
therafter, they were instructed to use 'manual full rich', and the engines went to full 'go-round' power properly

[Brian Coat]

From time to time we talk about the unsteady flow challenges of the turbocharger on here..

I stumbled across this Phd thesis from Imperial (where they have a very nice unsteady turbo test facility). It's about modelling these effects, which I think is interesting.

https://spiral.imperial.ac.uk/bitstream ... Thesis.pdf

[Craigy]

From time to time we talk about the unsteady flow challenges of the turbocharger on here..

I stumbled across this Phd thesis from Imperial (where they have a very nice unsteady turbo test facility). It's about modelling these effects, which I think is interesting.

https://spiral.imperial.ac.uk/bitstream ... Thesis.pdf

I was on a flight last night, and thought "I'll download that and read it on board". Unlikely on a short flight! It's about 300 pages, waffle aside. Seems interesting though.

[GoranF1]

Wazari

Muramassa wants a word whit you...



here's the part, screen shot of the page taken from preview on the publishers official website
33008594776_eae785b58d_o.jpg



Seems few f1technical forum people haunting this forum, why not anyone PM wazari to ask for full translation of this? In one of direct links to the page posted on this thread lately, I read wazari was writing he's native Japanese, if so then his English is exponentially better than me so it should be a piece of cake to translate this piece, in full and direct not paraphrase. Actually it doesnt prove anything more than that he's Japanese, but at least it confirms that particular claim.
Also can ask why he stole my translation, what exactly is the official paper of interview with press circulated on 30 Dec, and why its contents is only from sportiva.com articles published on 30 and 31 Dec featuring Hasegawa joint interview session conducted on 21 Dec and nothing from the rest which is massive amount, why had to sit on it for 10 days and wait for my translation, or why your one happened to have come out some 10 hours after I posted the translation on this forum, and again, why stole used and arranged my translation of the 2 articles

[FrukostScones]

? as far as I know you posted Muramasas translation here. (with quoting the source Muramasa, autosport forums)

What has Wazari to with this?

[GoranF1]

? as far as I know you posted Muramasas translation here. (with quoting the source Muramasa, autosport forums)

What has Wazari to with this?

Yes....but his problem is not me....i dont know what he wants...other than the facts he does this good translations he is a bit wierd guy....everybody seem to think so on A forums.....

[dren]

Who cares? You seem overly demanding of these people. Just take what they give at face value, like anyone else on the internet.

[GoranF1]

Who cares? You seem overly demanding of these people. Just take what they give at face value, like anyone else on the internet.

I have no idea what you just said