Honda Power Unit Hardware & Software

[aleks_ader]

As it was said before, get the combustion more efficient and you actually get less, not more energy for the turbine. They are already burning all of their fuel, but making the engine less susceptible to knocking allows them to increase their compression ratio, thus extracting more energy through the crankshaft, rather than trying to recover it through the turbine.

Overly simplifying, increasing the compression ratio gives you that energy at 100% efficiency, while recovering it through the turbine, transform it into electrical energy and then putting it to use is less than that.

That's my understanding of it, at least.

When you get it right - both crankshaft and turbine work will improve. Goals are:
1. Burn all the fuel with minimum dissociation (reverse reactions)
2. Complete the combustion as early after TDC as possible (without detonation of course.)
3. Minimise heat loss to the chamber
4. Maximise expansion before EVO

It is true as you say that finding increases in crankshaft work is more "desirable" than turbine work.

Apart from the obvious measures, almost everything you do to improve one of the above will disadvantage another.

Yes that is the main paradox of these new enginees. But choose witch way is overall the best. Or will be better on END of construction prosecess need to be know way before design phase. There is nice article in RET vol 172 (or 173) on that subject. Recoment reading (no comercial; just apreciate shear quallity before quantity of many "tech experts").

[mrluke]

Is exhaust to drive the turbine based on rpm or boost pressure? I mean normally one cannot occur without the other, but this F1 thing isn't normal. For all intents and purposes it's an electric supercharger/turbo, so boost pressure can exist independent of rpm. The turbine is being fed by the compressor, and the ICE, and we have a motor generator. My question is, given how efficient turbines are, would this turbine be able to use only MGU-H to be kept in self sustaining mode independent of ICE operation? Then when engine power exceeds MGU-H efficiency it goes into generator mode, much like we saw Mercedes do in Monza.

Youre 1st question is not clear for me, you are talking about driving the turbine and boost pressure, but those things are happening at different sides of the turbocharger .

About the 2nd question: Yes, this is possible. The MGU-H is able to deliver energy to the compressor when the turbine is not delivering enough power yet to the compressor and it can harvest energy from the turbine when the turbine delivers too much power.

It can even be kept in self-sustaining mode, which is called the "qualy" mode, because it can only be used for one lap (or when it is desired during the race) due to the limited battery capacity. In this mode the waste gate is fully opened to reduce the backpressure to the engine, while the MGU-H powers the compressor to deliver the desired boosted air.

Self sustaining mode is where the mguh is powering the mguk by bleeding excess boost pressure without taking any power from the ES. Hence the term self sustaining, it can carry on delivering this power output until you run out of fuel.

By contrast the qualy mode uses the ES to power the mugh and opens the wastegates to completely bypass the turbine, the turbo becomes an electronic supercharger and the ES also powers the MGUK.

[godlameroso]

Is exhaust to drive the turbine based on rpm or boost pressure? I mean normally one cannot occur without the other, but this F1 thing isn't normal. For all intents and purposes it's an electric supercharger/turbo, so boost pressure can exist independent of rpm. The turbine is being fed by the compressor, and the ICE, and we have a motor generator. My question is, given how efficient turbines are, would this turbine be able to use only MGU-H to be kept in self sustaining mode independent of ICE operation? Then when engine power exceeds MGU-H efficiency it goes into generator mode, much like we saw Mercedes do in Monza.

Youre 1st question is not clear for me, you are talking about driving the turbine and boost pressure, but those things are happening at different sides of the turbocharger .

About the 2nd question: Yes, this is possible. The MGU-H is able to deliver energy to the compressor when the turbine is not delivering enough power yet to the compressor and it can harvest energy from the turbine when the turbine delivers too much power.

It can even be kept in self-sustaining mode, which is called the "qualy" mode, because it can only be used for one lap (or when it is desired during the race) due to the limited battery capacity. In this mode the waste gate is fully opened to reduce the backpressure to the engine, while the MGU-H powers the compressor to deliver the desired boosted air.

But they happen within the same system, and the ICE is actually helping the compressor drive the turbine, acting like further stages in a conventional turbine jet engine. In a jet turbine engine that is one that does not have an ICE, the same process essentially happens. Air is compressed and then combusted to drive a turbine, which maintains the cylce as long as there's fuel. What I'm proposing is that the current engines are essentially a turbine engine, with an ICE and two motor generators in the middle to pick up the slack for the inefficiency inherent in the ICE. I'm asking if it's even possible to consider the power units this way, that is, as a turbine engine primarily and the combustion engine essentially functioning as the axial stages in the turbine, and the MGU+ES component to cover any inefficiency caused by the ICE. This way the ICE+transmission basically becomes nothing but a torque modulator.

[j.yank]

Does somebody know how long MGU-H has should work to overcome the turbo-lag?

That was kind of my point, the MGU-H would have to run longer (using more energy) in the Honda and Renault designs to overcome lag.

How much longer? If you make simple calculations based on the FIA rules you see that fractions of a second, even a second will not significantly decrease the energy balance of the whole system. Based on Monza this seems to me that MGU-H is harvesting and deploying to MGU-K normally but MGU-K itself is not harvesting in full - maybe deficit there is about 50% from the 2 MJ per lap limit. This put the whole system in disbalance which maybe is not too big but on tracks like Monza is becoming huge comparing to the other teams.

[alexx_88]

Figures from another thread (quite accurate iirc):
4MJ total harvest per lap: 1MJ recovered through the K and 3MJ recovered through the H.

I'm not really sure what you're talking about , if their H was was perfect, but K only 50% efficient, then they'd have 3MJ each lap. They don't. And it's also been widely accepted (even from within Honda) that they are having difficulties harvesting energy from the turbine.

[j.yank]

Figures from another thread (quite accurate iirc):
4MJ total harvest per lap: 1MJ recovered through the K and 3MJ recovered through the H.

I'm not really sure what you're talking about , if their H was was perfect, but K only 50% efficient, then they'd have 3MJ each lap. They don't. And it's also been widely accepted (even from within Honda) that they are having difficulties harvesting energy from the turbine.

I saw these figures but they are "standard" for all other teams. Monza is very specific track - you don't have too many corners where MGU-K can harvest energy and that's why it can not reach the limit of 2 MJ per lap. I guess that MH because of their problems harvest even less - maybe 0.5 MJ through MGU-K. This concerns only the harvesting function of MGU-K. The deployment function of 160 hp per second from MGU-K seems fine for me - this was the first race that I saw MH not be catch in the middle of straight - on the start and the finish of the straight but not in middle. This can not be done without these 160 hp from the MGU-K. But the lack of 0.5 MJ was fatal - this deficit on the straight should be covered by the energy harvested from MGU-H but this creates deficit in ES that is seen on the corner exits and then again on the straights. It is like a spiral of financial debt - you don't have enough resources to go out of it.

[PlatinumZealot]

looking at the pictures how high the Honda turbo is compared to the Mercedes' makes me wonder. Honda (or better, McLaren) knew somewhere during 2013 how the layout of the Mercedes engine would be, and in the first parts of 2014 how efficient the unit with the huge compressor is (with having the compressor in front of the crankshaft, there is almost no limit with the diameter).

It is really time available I think. Honda just did not have enough time. These designs are so complex that to change the fundamental backbone of it can take years. (Ask any engineer that works in big company! lol)

Ferrari did it in less than a year. Honda seem to have chosen to follow ferrari down a dead end route despite having spent a year watching ferrari do it.

A wise man doesn't just learn from his own mistakes, he also learns from the mistakes made by others.

They did not change anything fundamental and remember Ferrari had 3 years of development plus one year of actual race use.

[gruntguru]

From what I have seen:

- Both Honda and Renault are using an air-air intercooler in the side pods.
- Ferrari use an air-water intercooler located in the vee of the engine.
- Mercedes use an air-water intercooler located above the fuel tank.

The Merc and Ferrari solutions have less volume in the high pressure air system between the compressor and the inlet valves. The Renault and Honda solutions have significantly more volume in the high pressure air system between the compressor and the inlet valves.

The additional volume in the Renault and Honda solutions must impact power production and efficiency, as compressing the additional air must consume some energy.

How much do you think this has to do with both Honda's and Renault's woes?

None. The airflow through the engine is around 500 litres/sec. Filling an extra one or two litres of ducting is not significant.

[alexx_88]

Figures from another thread (quite accurate iirc):
4MJ total harvest per lap: 1MJ recovered through the K and 3MJ recovered through the H.

I'm not really sure what you're talking about , if their H was was perfect, but K only 50% efficient, then they'd have 3MJ each lap. They don't. And it's also been widely accepted (even from within Honda) that they are having difficulties harvesting energy from the turbine.

I saw these figures but they are "standard" for all other teams. Monza is very specific track - you don't have too many corners where MGU-K can harvest energy and that's why it can not reach the limit of 2 MJ per lap. I guess that MH because of their problems harvest even less - maybe 0.5 MJ through MGU-K. This concerns only the harvesting function of MGU-K. The deployment function of 160 hp per second from MGU-K seems fine for me - this was the first race that I saw MH not be catch in the middle of straight - on the start and the finish of the straight but not in middle. This can not be done without these 160 hp from the MGU-K. But the lack of 0.5 MJ was fatal - this deficit on the straight should be covered by the energy harvested from MGU-H but this creates deficit in ES that is seen on the corner exits and then again on the straights. It is like a spiral of financial debt - you don't have enough resources to go out of it.

Brembo brake facts: Italy (117kWh), Spa (101kWh) and Silverstone (85kWh). Monza is the exact opposite of what you describe, as it's one of the top circuits on the calendar regarding the potential to harvest energy from braking.

At Monza, as it was the case at Spa, the Mclaren lacked ~15-20km/h in top speed on the long straights which suggests they didn't have enough power being output through the MGU-K at that point. The exact reasons are thought to be related to the MGU-H's ability to recover power from the turbine and feed it into the MGU-K. Most likely the first part. I've posted a video in the engine thread which shows that, at the end of the main straight in Monza, the Merc engines continue to increase in speed but, at the same time, charge their batteries. That's energy coming from the MGU-H which isn't happening in the Honda PU.

[wuzak]

Brembo brake facts: Italy (117kWh), Spa (101kWh) and Silverstone (85kWh). Monza is the exact opposite of what you describe, as it's one of the top circuits on the calendar regarding the potential to harvest energy from braking.

No, it is not one of the top circuits on the calendar for brake recovery. In fact it is average, or slightly below, the average harvest at all circuits.

The numbers you quote there are for the whole braking system. More than half that goes through the front brake, and cannot be recovered.

And the MGUK can take only 120kW of the rear braking power available.

So the question is, how much time is spent braking where the rear brakes are generating 120kW or braking or better?

Singapore is the best circuit on the calendar for MGUK recovery - more than twice Monza (better than the 2MJ limit in the rules), and around three times that of Silverstone.

[alexx_88]

@Wuzak: Where did you get your figures from? I mean the amount of energy available for harvesting at each circuit. Logic dictates me that, besides the brake bias (which is mostly corner dependent), if you're dissipating more energy through braking, then there's more to be recovered as well. Obviously braking duration is key here, but 1MJ (which is the number I've seen being mentioned as harvested by the MGU-K over a lap) only takes 8s of braking to be harvested. Even Monza has significantly more than that.

In any case, I was simply contradicting the affirmation that Honda's woes come from the insufficient harvesting from the MGU-K when they have actually been reported to come from the lack of harvesting from the MGU-H.

[j.yank]

I've posted a video in the engine thread which shows that, at the end of the main straight in Monza, the Merc engines continue to increase in speed but, at the same time, charge their batteries. That's energy coming from the MGU-H which isn't happening in the Honda PU.

Actually the power of MGU-H is probably no more than 40 kw. What you are describing what Mercedes is doing at the end of the straight is the normal operation of harvesting energy through MGU-H when you are on full throttle but this doesn't mean that this energy is immediately sent to MGU-K for speeding up the car. Most likely it is stored in ES to be used on the exit of the upcoming corners and acceleration on the start of the next straights. Meanwhile McLaren-Honda is forced to send to MGU-K all available and coming energy from MGU-H in order to deliver 160 hp on the straight but then it should start brake earlier to harvest energy through MGU-K that it will need in the next corners and straights. The problem is not to have the full pick power on one straight but to have energy for all other tasks throughout the whole lap. Distributing the limited available energy causes not to be able to run at full power in every given moment (this is about Monza). Wuzak has explained about the barking energy.

[j.yank]

In any case, I was simply contradicting the affirmation that Honda's woes come from the insufficient harvesting from the MGU-K when they have actually been reported to come from the lack of harvesting from the MGU-H.

The idea that MGU-H is not the problem but harvesting from MGU-K is, came from this:
Arai: "This circuit is very difficult for our power unit because the MGU-K is 120kw, but MGU-H is applied more time on the straight, so it is very difficult for us."
http://www.motorsport.com/f1/news/honda ... -for-2016/

He doesn't say that MGU-H don't deliver enough energy but just the opposite - it is used too much on the straight, and there is not enough energy left for other parts of the lap. This is supported by another Arai statement - that in Hungary they had surplus of energy, not deficit. But this can not be done with non-functional MGU-H because MGU-K can harvest only 2 MJ per lap.

[alexx_88]

I think we are doing circles around the same idea. Let me try and sum it up and let me know which part you don't agree with:

1. The goal of the ERS in this formula is to maximize the amount of time you are able to drive the MGU-K at the 120kW.
2. In order to do that, you have two sources of energy: the ES and the MGU-H
3. As it has been reported, over the course of a lap, 75% of the energy stored in the ES comes from the MGU-H, while the other 25% from the MGU-K
4. It has been said a number of times on this forum that achieving the MGU-K harvesting targets is easier than the MGU-H's. As shown by Ferrari last year who under-sized their turbine, being unable to recover sufficient energy through the MGU-H.
5. As was reported from the Honda camp, their problem is harvesting enough energy to maximize the amount of time they can drive their MGU-K at full power. My opinion is that their issues stem mainly from the inability to reach the harvesting targets for the MGU-H.

On which part of the argument are we not agreeing?

PS: Just saw your post. If they are able to get enough energy from the MGU-H, why were they running out of electrical energy after half a lap at Spa? Or, let me put it the other way. If the MGU-K harvesting only amount to 25% of the total energy harvested, why are they running out of energy so soon?

[j.yank]

I think we are doing circles around the same idea. Let me try and sum it up and let me know which part you don't agree with:

1. The goal of the ERS in this formula is to maximize the amount of time you are able to drive the MGU-K at the 120kW.
2. In order to do that, you have two sources of energy: the ES and the MGU-H
3. As it has been reported, over the course of a lap, 75% of the energy stored in the ES comes from the MGU-H, while the other 25% from the MGU-K
4. It has been said a number of times on this forum that achieving the MGU-K harvesting targets is easier than the MGU-H's. As shown by Ferrari last year who under-sized their turbine, being unable to recover sufficient energy through the MGU-H.
5. As was reported from the Honda camp, their problem is harvesting enough energy to maximize the amount of time they can drive their MGU-K at full power. My opinion is that their issues stem mainly from the inability to reach the harvesting targets for the MGU-H.

On which part of the argument are we not agreeing?

PS: Just saw your post. If they are able to get enough energy from the MGU-H, why were they running out of electrical energy after half a lap at Spa? Or, let me put it the other way. If the MGU-K harvesting only amount to 25% of the total energy harvested, why are they running out of energy so soon?

Good approach! =D> 1. and 2. I think are indisputable. Should be specified that 3. is valid only for Monza - normally MGU-K should provide 2 MJ per lap. The disagreements start in 4. We don't know which one is easier, especially for Honda case where no one actually has any real information. Ferrari's problems last year where more related to undersized compressor and if I remember this right, the strange decision the energy from MGU-H always to go through the ES first instead directly to be linked to MGU-K. If you don't have big enough compressor you will not have enough ICE power. In this case you can have the best MGU-H but this will not make the required end pick power. About 5.: if they have problems reaching the harvesting targets from MGU-H they will experience sever energy deficit not only on tracks like Monza but on circuits like Hungaroring. But Arai said that they were OK there. Also, on Monza if they had MGU-H problem they would not be able to hold (around 6-7 laps) four cars for two laps, not to speak to try to fight with them on the straights like Button did. Honestly I expected much worse performance there and the fact they were lapped only once on this track is nice surprise. If they had not functional MGU-H, 2 laps behind the leader should be guaranteed on Monza.