- Login or Register
No account yet? Sign up
Formula One's governing body has announced that it has come to a settlement with Scuderia Ferrari after investigations into its 2019 power unit, considered the most powered in F1.
Some good points there TC. Makes me wonder about HCCI, post spark AI and whether either of these ignition modes includes any degree of detonation and if so - why are they not damaging in the way detonation can be?Tommy Cookers wrote:traditionally ignition/combustion was a big grey area .....iichel wrote:How do you see auto ignition post spark? Partial flame front and anything that was not reached in the flame front will self-combust? What is the point of the spark in that case?
carburettor engines quite often ran on auto ignition post spark (visibly continuing idling after ignition cutoff, and invisibly at high power) this is not pressingly detrimental to the engine compared to pure SI, combustion will be completed earlier and so efficiency and power will be greater notionally this is an engine configuration that will neither auto ignite without initial SI nor pre-ignite with SI in principle, with the omnicapable DI etc, we can now put the engine in this region and keep it there
HCCI is about combusting at high AFRs unuseable via SI alone (ie AFRs also limiting peak combustion pressures to mechanically safe levels) as our F1 engines cannot prepare the charge as HCCI does, they may be emulating HCCI mode with CI, not true HCCI and in principle there will still be a region of conditions between HCCI/CI and SI without any auto ignition ?
erm..Russia, as the headline says !?Sevach wrote:http://www.motorsport.com/f1/news/ferra ... gp-689198/
When will this theoretical super engine appear?
#aerogollumturbof1 wrote: YOU SHALL NOT......STALLLLL!!!
An ignition system for an internal combustion engine having at least one combustion chamber where the ignition system includes a housing, an ignition device, an injector, and a pre-chamber having a nozzle disposed spaced from the proximal portion of the pre-chamber. The igniter portion of the ignition device and the nozzle of the injector are operatively supported in the proximal portion of the pre-chamber and disposed flush therewith. The igniter portion ignites the fuel in pre-chamber such that partially combusted pre-chamber products are forced through orifices in the pre-chamber nozzle and extinguish, but dispersed through the combustion chamber so as to ignite the main fuel charge therein.
It has similarities to the HCCI system previously described in that only the mix within the small chamber needs to be relatively rich; that in the main chamber – because it will be ignited by the already sparked fuel mixture released from the pre-chamber – can be much weaker (ie less fuel, more air) than it would otherwise need to be to avoid detonation, by as much as 20%. The further you can push the detonation limit, the bigger the bang you can safely produce and therefore the power output increases.
The ingenious trick here is that the air-fuel mixture is pre-ignited in a pre-chamber around the spark plug. This results in the formation of plasma jets that reach the piston primarily at the outer edge and ignite the remainder of the mixture. While ignition normally takes place in the centre of the cylinder, with Mahle Jet Ignition it essentially takes place from the outside toward the inside. This allows significantly better combustion of the fuel mixture. The result: more power with considerably less residue.
__________________Whilst the engine manufacturers have likely looked at the merits of implementing HCCI in its normal form, it is actually MAHLE's Jet Ignition system they are using to improve the combustion process.
Although similar to the processes involved in HCCI, the MAHLE system offers up a more finely controlled fuel delivery system in tandem with the standard spark plug to increase the overall operating window.
The MAHLE Jet Ignition system uses an ignition chamber, which fires compressed fuel into the cylinder to cause auto-ignition under certain conditions, whilst the normal fuel delivery and spark plug are used under other conditions.
Interestingly the regulations only permit five sparks per cycle, but the use of the jet ignitor means this can be extended, as the mixture within the cylinder can also have multiple auto ignitions, a neat way of improving the potency and efficiency of each cycle.
Therefore careful design of the injector, jet ignitor, spark plug, cylinder and piston crown can lead to a multi-modal fuel strategy, allowing the use of both stratified charging and homogeneous charging depending on the prevailing throttle demand. This can improve fuel efficiency as well as performance.
HCCI: its evolution was inspired by technology "Mahle Jet Ignition?
And here we come to the latest information gathered by FUnoAnalisiTecnica: it would seem that in what we called HCCI Plus was introduced a small pre chamber on each piston which communicates directly with the main combustion chamber. It 'just inside this tiny room secondary combustion which would be compressed "spontaneously" a small amount of rather rich mixture. It seems to have evolved so difficult HCCI technology, taking advantage of some of the advantages present in another interesting technology patented by the company Mahle: the " Jet Ignition ".
It fact, exploits a pre outer chamber to the combustion chamber proper to turn on, in this case for temperature (therefore with a candle) and not for pressure as nell'HCCI, a small amount of mixture that will be then sent in the room of combustion to complete the ignition of the rest of the charge, very very lean in this case.
Returning all'HCCI, other loads, when combustion occurs by spark ignition, it will be a "classic" candle to ignite the mixture of air - fuel . In this case, the secondary combustion chamber is bypassed, only exploiting the main combustion chamber.
Thanks to the changes set out above, it seems that the engineers have managed to come up with the combustion efficiency up to values over 45%.
FERRARI: the Mahle company already collaborates with Ferrari and Mercedes!
It 'a few days the announcement that Mahle, company that designed the innovative lean combustion process faster described just above, has expanded its partnership with Scuderia Ferrari by including in the provision also "crucial" defined components of the combustion engine internal.
" We consider MAHLE an important partner in the ongoing development of our engines ," said James Allison, Technical Director of Scuderia Ferrari. " We appreciate not only their high level of technological expertise, but also the exceptional reliability of their products ."
But apparently the Mahle development activities for Ferrari are also found in innovative combustion processes , become vital in the age of these complex hybrid engines.
I discussed this some weeks ago on autosport before the story 'broke' and hypothesized 2 ways the TJI system could be implemented within the current regulations.wuzak wrote:Except that only one injector is allowed, and it is a direct injection system.
1- that is still a separate injector so breaches the rules.mistareno wrote:I discussed this some weeks ago on autosport before the story 'broke' and hypothesized 2 ways the TJI system could be implemented within the current regulations.wuzak wrote:Except that only one injector is allowed, and it is a direct injection system.
The wording states only 1 (direct) injector is allowed per cylinder and no fuel can be injected upstream of the inlet valve or downstream of the exhaust valve.
1-
It could be argued that the small injector contained within the TJI housing is actually not 'for the cylinder' as it only provides enough fuel to facilitate the flame jets that then ignite the main charge (which is fueled by a conventional DI)
Or
2-
The injector within the TJI has specific multiple nozzles (and perhaps even multiple piezo/solenoid actuators) within a single injector that automatically distribute 3% of fuel to the TJI pre chamber and the other 97% to the combustion chamber. This would be more complicated but would comply with any interpretation of the rules.