Mercedes Power Unit Hardware & Software

[dans79]

https://twitter.com/scarbstech/status/1 ... 72809?s=21

https://twitter.com/scarbstech/status/1 ... 77888?s=21

I'm not seeing how the first tweet calling it a pressure vessel would work. Air has to flow through it, even at low rpm.

Also the intake air temperature goes up if the pressure is increased. I must be reading it wrong...

Yep, no way of cheating the ideal gas law.

[Hoffman900]

I'm not seeing how the first tweet calling it a pressure vessel would work. Air has to flow through it, even at low rpm.

Also the intake air temperature goes up if the pressure is increased. I must be reading it wrong...

Yep, no way if cheating the ideal gas law.

Yep. Air conditioners work on the principle of compressing gas and expanding it. Anyone who has held a compressor nozzle against their hand and felt how cool it was, while the compressor tank is warm to touch knows this.

Porsche used increased boost pressure to design an inlet tract that causes in cylinder temps to drop 20*C as compared to before. It’s not a lot, but it adds up, and works for them.

[henry]

The Peltier effect is horribly inefficient though, they would need to have a lot of spare electrical power they don't know what to do with.

Good point.

I bet the can produce more electricity under braking than they can store already tho...

So why not bleed to peltiers?

You would lose that bet. At almost all circuits, Singapore is an exception, they fail to recover 2 MJ from braking. In most places 1 MJ is a stretch.

[jure]

This may be a long shot, but an alternative to peltier effect could be magneto-caloric effect. Basically a magnetic refrigerator, but they would probably need a "cold reservoir" for it to have any long lasting effect. Of course this is only worth it, if one has too much electricity, which Mercedes does not seem to have (deployment issues).

[Zynerji]

Good point.

I bet the can produce more electricity under braking than they can store already tho...

So why not bleed to peltiers?

You would lose that bet. At almost all circuits, Singapore is an exception, they fail to recover 2 MJ from braking. In most places 1 MJ is a stretch.

With the mguh still buzzing...

[b2bL44]

https://the-race.com/formula-1/red-bull ... -with-fia/

Red Bull query Mercedes F1 engine sensors with FIA

The competitive niggle between Formula 1 title rivals Red Bull and Mercedes appears to be continuing as Red Bull has made a query to the FIA regarding the sensors of the Mercedes power unit that record the engine’s inlet plenum temperatures, The Race has learned.

The lower the temperature, the more dense the oxygen content and the greater the combustion will be. By regulation, the plenum air temperature must be at least 10-deg above the external ambient temperature (as an average over the lap) and the FIA sensors track this to ensure compliance.

The Mercedes inlet plenum is believed to have walls that can be filled with super-cooled liquid.

This would more effectively cool the air within the plenum chamber, which would be useful in the acceleration phase but would only be a brief burst as the super-cooling of the liquid would not be sustained.

This would be consistent with the observation Red Bull has made that the Mercedes power unit has a big power delivery on initial acceleration phases which then dampens out.

It is important to emphasise that super-cooling of the liquid in walls in the plenum does not imply that the air within the plenum is below the legal minimum temperature. But it would certainly cool it more effectively.

Red Bull is questioning whether the temperature sensors are situated in a place that would capture any dipping below the legal minimum.

Other teams are aware of the theory but are wary of buying into it without a fuller understanding of the precise mechanism.

[Hoffman900]

Assuming this is the case, it would be really hard to enforce with the one lap average rule.

Going to an instantaneous rule, or 3 second rule, would likely catch them all out would be my guess.

[zibby43]

Merc PU is good-to-go.

https://www.funoanalisitecnica.com/2021 ... ull-6.html

In summary, Merc were able to get on top of the new plenum design and utilize more powerful engine modes in the race in Hungary. Modes they hadn’t used all season in a race setting (Strat 4; HPP 7). RBR took notice that now Merc ruled the straights with powerful acceleration.

The article also points out that Merc have always toed the line with respect to PU legality.

“It is necessary to underline another evidence: until proven otherwise, Mercedes has always operated within the framework of legality . This is because the German engineer forged the engine with the regulation in hand. A PU which, among other things, has received all the necessary and required technical approvals in a year in which, due to a technical freeze, the checks are more stringent . On the other hand, if the FIA has never found anomalies and the temperatures recorded by the sensor have not triggered alarms, there is not too much room for the hypothetical Red Bull appeal to be accepted.”

However, even in the remote possibility that Merc were operating in a gray area, there’s no way that Merc could redesign the PU for itself or customer teams this year, so the FIA would do nothing about it this year. It’s not only the PU that would need to change, but everyone’s chassis, too.

TL; DR: Merc are probably 100% legal, but even if they are more in a gray area, then they’re still good-to-go.

[SiLo]

Where are they storing this "super-cooled" fluid that could sit in the walls of the plenum without heating up drastically over a race or even a few laps? The entire engine area runs very hot, I find it hard to believe they could be doing something like that, and find it more probably that reliability and software changes have led to them finally unlocking the inherent performance in the engine.

[OO7]

Merc PU is good-to-go.

https://www.funoanalisitecnica.com/2021 ... ull-6.html

In summary, Merc were able to get on top of the new plenum design and utilize more powerful engine modes in the race in Hungary. Modes they hadn’t used all season in a race setting (Strat 4; HPP 7). RBR took notice that now Merc ruled the straights with powerful acceleration.

The article also points out that Merc have always toed the line with respect to PU legality.

“It is necessary to underline another evidence: until proven otherwise, Mercedes has always operated within the framework of legality . This is because the German engineer forged the engine with the regulation in hand. A PU which, among other things, has received all the necessary and required technical approvals in a year in which, due to a technical freeze, the checks are more stringent . On the other hand, if the FIA has never found anomalies and the temperatures recorded by the sensor have not triggered alarms, there is not too much room for the hypothetical Red Bull appeal to be accepted.”

However, even in the remote possibility that Merc were operating in a gray area, there’s no way that Merc could redesign the PU for itself or customer teams this year, so the FIA would do nothing about it this year. It’s not only the PU that would need to change, but everyone’s chassis, too.

TL; DR: Merc are probably 100% legal, but even if they are more in a gray area, then they’re still good-to-go.

zibby if that's the case, I foresee a few people on that other site being quite upset.

[djones]

If there is one thing we have learnt about Mercedes it's that they do everything as per the rules. This is probably to protect brand reputation.

I know people will be furiously typing things like "oil-burning" but the truth is that was only ever theory based on the back of the fact the Mercedes engine was just really good compared to the rest. They were not the ones with extra oil tanks etc.

Anyway, my point is I guarantee whatever they are doing with the temperatures (if anything) is totally within the rules.

[El Scorchio]

If there is one thing we have learnt about Mercedes it's that they do everything as per the rules. This is probably to protect brand reputation.

I know people will be furiously typing things like "oil-burning" but the truth is that was only ever theory based on the back of the fact the Mercedes engine was just really good compared to the rest. They were not the ones with extra oil tanks etc.

Anyway, my point is I guarantee whatever they are doing with the temperatures (if anything) is totally within the rules.

Quite probably true- and look at how they cleared DAS with the powers that be before implementing it- but it's certainly not going to stop people throwing all sorts of accusations around, as history tells us!

[_cerber1]

https://the-race.com/formula-1/mercedes ... ine-query/

“We love the fact they are spending time on these things and researching and very welcome very much any initiative they wish to do and then look at it”

[Zynerji]

I'm happy to just learn more. I hope they get "caught" with something, just so we can see some new tech!

[dans79]

Where are they storing this "super-cooled" fluid that could sit in the walls of the plenum without heating up drastically over a race or even a few laps? The entire engine area runs very hot, I find it hard to believe they could be doing something like that, and find it more probably that reliability and software changes have led to them finally unlocking the inherent performance in the engine.

Yea, That's one of the problems with the super cooled line of thought. The other is that the coolant but be exceptionally pure, and it must stay that way. If the water has any impurities in it, or the container its stored in has any, you have a point of nucleation and the whole concept goes out the window.