F1technical.net

IvailoStefanovBG wrote: ↑

31 Jul 2019, 07:47

Does somenody know what is the lowest possible operating temperature suitable for cylinder head and cobustion chamber to prevent knocking?

Higher is always desirable except the NOX portion. But don't mix it up with combustion temperature, and little bit knock would also desirable if you want to achieve self ignition (HCCI). The key is how to achieve this without compromizing too much on reliability. The lean burn one (lamda about 2) would be about 850-900 degree, and its still far from what the manufacturer can achieve right now. The operating temperature would be lower than 180 degrees as aluminium cant allow anything higher than that.

Singabule wrote: ↑

31 Jul 2019, 08:39

IvailoStefanovBG wrote: ↑

31 Jul 2019, 07:47

Does somenody know what is the lowest possible operating temperature suitable for cylinder head and combustion chamber to prevent knocking?

Higher is always desirable except the NOX portion. But don't mix it up with combustion temperature, and little bit knock would also desirable if you want to achieve self ignition (HCCI). The key is how to achieve this without compromizing too much on reliability. The lean burn one (lamda about 2) would be about 850-900 degree, and its still far from what the manufacturer can achieve right now. The operating temperature would be lower than 180 degrees as aluminium cant allow anything higher than that.

So is there any chance they use some kind of refrigerant cycle to cool combsution chamber and cylinder head with temperatures below ambient?

IvailoStefanovBG wrote: ↑

31 Jul 2019, 08:45

Singabule wrote: ↑

31 Jul 2019, 08:39

IvailoStefanovBG wrote: ↑

31 Jul 2019, 07:47

Does somenody know what is the lowest possible operating temperature suitable for cylinder head and combustion chamber to prevent knocking?

Higher is always desirable except the NOX portion. But don't mix it up with combustion temperature, and little bit knock would also desirable if you want to achieve self ignition (HCCI). The key is how to achieve this without compromizing too much on reliability. The lean burn one (lamda about 2) would be about 850-900 degree, and its still far from what the manufacturer can achieve right now. The operating temperature would be lower than 180 degrees as aluminium cant allow anything higher than that.

So is there any chance they use some kind of refrigerant cycle to cool combsution chamber and cylinder head with temperatures below ambient?

Well thats too much off topic, but why you want to reduce to below ambient (30 degrees)? This is ICE not processor OC.

IvailoStefanovBG wrote: ↑

31 Jul 2019, 08:45

Singabule wrote: ↑

31 Jul 2019, 08:39

IvailoStefanovBG wrote: ↑

31 Jul 2019, 07:47

Does somenody know what is the lowest possible operating temperature suitable for cylinder head and combustion chamber to prevent knocking?

Higher is always desirable except the NOX portion. But don't mix it up with combustion temperature, and little bit knock would also desirable if you want to achieve self ignition (HCCI). The key is how to achieve this without compromizing too much on reliability. The lean burn one (lamda about 2) would be about 850-900 degree, and its still far from what the manufacturer can achieve right now. The operating temperature would be lower than 180 degrees as aluminium cant allow anything higher than that.

So is there any chance they use some kind of refrigerant cycle to cool combsution chamber and cylinder head with temperatures below ambient?

Well thats too much off topic, but why you want to reduce to below ambient (30 degrees)? This is ICE not processor OC.

Last time I was following the subject (temperatures at point of combustion) it was stated that the instantaneous gas temperature at point of combustion in a modern F1 engine can reach up to 2600 degree C.

IvailoStefanovBG wrote: ↑

31 Jul 2019, 07:47

Does somenody know what is the lowest possible operating temperature suitable for cylinder head and cobustion chamber to prevent knocking?

OK You are talking about the engine block and cylinder head temperature?

Block / head temperature not be too hot to make the lubricating oil too runny, and also the temperature near the combustion chamber must allow heat rejection from any hot spots inside the chamber. The temperatures throughout the head/block are not even though. The designer locates the cooling near the hot areas.

saviour stivala wrote: ↑

31 Jul 2019, 09:29

Last time I was following the subject (temperatures at point of combustion) it was stated that the instantaneous gas temperature at point of combustion in a modern F1 engine can reach up to 2600 degree C.

Yes, and that way much higher than the best (HCCI) may achieve. 2600 is referring to the modern F1 non turbocharged one. Still a lot room for improvement for current regs, hence the manufacturer quite hesitant to move on. SCCI and TJI are the stop gap towards HCCI. The target always to lower the avarage combustion temperature by adding the air mass and complete instantegeous combustion, increase the heat rejection from cylinder wall, reduce the friction, reduce the cooling requirement and heat loss by all of that factor. The heat excess then captured by turbo compound. Thats the current engine regulations and its really pinnacle of technology.

2600 degree C was referring to the modern F1 turbocharged ICE instantaneous gas temperature at point of combustion.

IvailoStefanovBG wrote: ↑

31 Jul 2019, 08:45

Singabule wrote: ↑

31 Jul 2019, 08:39

IvailoStefanovBG wrote: ↑

31 Jul 2019, 07:47

Does somenody know what is the lowest possible operating temperature suitable for cylinder head and combustion chamber to prevent knocking?

Higher is always desirable except the NOX portion. But don't mix it up with combustion temperature, and little bit knock would also desirable if you want to achieve self ignition (HCCI). The key is how to achieve this without compromizing too much on reliability. The lean burn one (lamda about 2) would be about 850-900 degree, and its still far from what the manufacturer can achieve right now. The operating temperature would be lower than 180 degrees as aluminium cant allow anything higher than that.

So is there any chance they use some kind of refrigerant cycle to cool combsution chamber and cylinder head with temperatures below ambient?

Not legal AFAIK. There is a rule outlawing the use of phase changes in cooling systems.
(I guess that would not prohibit some kind of gas-cycle refrigeration but those are typically bulky and less efficient)

gruntguru wrote: ↑

01 Aug 2019, 00:59

IvailoStefanovBG wrote: ↑

31 Jul 2019, 08:45

Singabule wrote: ↑

31 Jul 2019, 08:39

Higher is always desirable except the NOX portion. But don't mix it up with combustion temperature, and little bit knock would also desirable if you want to achieve self ignition (HCCI). The key is how to achieve this without compromizing too much on reliability. The lean burn one (lamda about 2) would be about 850-900 degree, and its still far from what the manufacturer can achieve right now. The operating temperature would be lower than 180 degrees as aluminium cant allow anything higher than that.

So is there any chance they use some kind of refrigerant cycle to cool combsution chamber and cylinder head with temperatures below ambient?

Not legal AFAIK. There is a rule outlawing the use of phase changes in cooling systems.
(I guess that would not prohibit some kind of gas-cycle refrigeration but those are typically bulky and less efficient)

I kept thinking of that rule when when water boiling was being brought up these last few pages.

The argument would be that "nucleate boiling" simply helps transfer heat from the metal surface to somewhere deeper in the fluid flow (where the bubbles condense) but still within the heat generating device (engine), as opposed to transferring heat to the heat rejection device (radiator).

If vapor bubbles did travel to the radiators, it would be hard to police. If components of coolant had different boiling points perhaps a phase change could be hidden. Bubbles of vapor or steam taken away from the engine toward the radiators to condense. Water in silicone, kerosene, or glycol. Alcohol, acetone, methanol, benzene, petrol, etc., in water. For example. Maybe surfactants or emulsifiers could be used to control bubble size. Goal: a coolant which can transition from a liquid to a fine liquid foam via boiling and condensation of a fractional component(s).

gruntguru wrote: ↑

01 Aug 2019, 05:02

The argument would be that "nucleate boiling" simply helps transfer heat from the metal surface to somewhere deeper in the fluid flow (where the bubbles condense) but still within the heat generating device (engine), as opposed to transferring heat to the heat rejection device (radiator).

The coolant inside the engine is part of the heat rejection device, however.

In the wider context of the discussion we might consider use of metallic particles to increase the heat transfer rate of the solvent.

Mclaren did at one point have research going into aluminium nanoparticle-filled coolant. They didn't use it when they had the Honda in though.

https://f1-motorsports-gp.com/

This blog analyzed the speed of every 0.1 seconds of both cars by telemetry at austlia GP.
The data was from lap 61 of VER and lap 58 of LEC from the approach of turn 1 to the point of brake at turn 3.
At turn1 both drivers selected 4th gear, the bottom speed of VER was 136kmh, and accelerated immediately.
On the other hand, which of LEC was 131kmh and ran at the speed for 0.5sec.
VER had a full throttle at 155kmh. LEC had it at 165kmh.
Ferrari has low drag and was superior in acceleration performance and its maximum speed was 304kmh.
As for RB, acceleration became slightly dull from 287kmh and recorded 299kmh for max speed.
It might be said that VER had the fast lap time thanks to cornering performance of RB.



Comparison of acceleration performance of LEC and VER
This graph was plotted of both cars speeds from 165kmh(when LEC had full throttle).
Against expectations,to 290kmh,VER only lost to LEC just a little.
Considering of the drug of RB, RA619H might be as same performance as ferrari until 290kmh.
The point that should be improved for Honda is over 290kmh.

PhillipM wrote: ↑

01 Aug 2019, 08:05

Mclaren did at one point have research going into aluminium nanoparticle-filled coolant. They didn't use it when they had the Honda in though.

I came across this interesting research with current application being in HVAC systems to boost capacity by 5x. Granted it’s “biphasic”, so it wouldn’t be allowed, but interesting none the less.

https://phys.org/news/2019-08-approach ... cient.html