change advances

[dott.chem]

It is a problem of kinetic type.
The diesel ? slow to burn. By injecting up to 10 degrees (approximately, varies from motor to motor) does not have the time to burn during the phase of the useful and ends to get to the exhaust manifold and the snail of the turbine during the combustion phase. There? causes an increase of EGT and particulate matter.
The phenomenon is reduced by using large excesses of air, of course. With low-pressure turbo-high, often this limit is a little less.
The camshafts increase the volumetric efficiency, as a result ? as if you're using pressure turbo more? high (not ? just cos? but you get the idea)

[munro]

It is a problem of kinetic type.
The diesel ? slow to burn. By injecting up to 10 degrees (approximately, varies from motor to motor) does not have the time to burn during the phase of the useful and ends to get to the exhaust manifold and the snail of the turbine during the combustion phase. There? causes an increase of EGT and particulate matter.
The phenomenon is reduced by using large excesses of air, of course. With low-pressure turbo-high, often this limit is a little less.
The camshafts increase the volumetric efficiency, as a result ? as if you're using pressure turbo more? high (not ? just cos? but you get the idea)

ok...putting a moment by the volumetric efficiency data from a certain type of cam, or pressure turbo etc and taking into consideration only the thermal cycle of a given engine and thus the pme that derives from it...my question ?:from when is the beginning of the injection of the diesel fuel, the intake valves have been closed already, such a beautiful piece,as well as the exhaust,and that air under pressure ? managed to enter in the cylinder ? the entrance to stop...then in the cylinder c'? a certain amount of pressure at the end of the compression phase of sara has also been increased in the heat ok?.. then in this condition ? match the combustion and we say "while" the piston passes the tdc..... what I did not go back ?=why? in the cylinder can not continue to inject diesel fuel into the mass which already is burning with a temperature and pressure much higher stage of compression to verebbe "interotta" only until the exhaust valve decides to open up??cinematicamente talking about the doc,why? by injecting 10?after the pms you should have more egt and smoke when it seems clear that the exhaust valve ? still closed, and all the heat and the pressure ? still trapped in the cylinder and pressed with a force unheard of on the piston??

[cicciogsr]

in mjet the injections are multiple, in fact, you inject diesel in different times even when the combustion ? started

[munro]

if you allow me I would like to hear those who waste 2 words to try to understand us poor ingnoranti difficult concepts....and I am referring to dr. chem that as from his previous posts, evidently "waste" a few words to make it understandable concepts...translated and no offense...ciccio you're a great guy and an engineer titrated but to explain things you are a kiavika!!!forgive me!!
I believe that the combustion of the diesel the including and my questions are specifichea which I would like specific answers if you also don't want to give in this case I would like to ask you to avoid beating around the bush with useless wordplays....do not return to say and do the same things....come on!! a p? in a practical sense we want to!! the Doc sort of said what she thought without getting many saws mental!! why don't you adapt you or if that's just do you find it difficult from there? why do not you abstain to continue to "fight the can to the air??"

[cicciogsr]

changing the camshaft changes the volumetric efficiency why? change the timing of opening of the valves with a result of better and more filling the room... for the best I mean the speed? with which it fills the second what if ? well done best the intersection of valve you can empty the room first, and then fills the first and the fresh mixture, that you will have to? turn on is a room completely devoid of gas, with a few residues of unburnt and well as ir? the cool thing not to be underestimated

[cicciogsr]

if you re-read everything from scratch I have also explained how the combustion of the diesel... looking for info on the combustion of the diesel, especially on the spread and maybe you put a lot of doubt

[dott.chem]

The process of combustion of any fuel with the oxidizer (in this case fuel and air) ? a chemical reaction.
The chemical reactions, all of which have a speed? typical that depends on several things.
Furthermore, the temperature and the pressure govern, in part, the thermodynamics of the combustion process.
In the specific case, an increase in pressure does not play in favour of the combustion process, at least from the thermodynamic point of view
In addition, from the point of view of kinetic phenomenon, chemical, "combustion" ? accompanied by physical phenomenon.
The drops of diesel micrometer, tend to burn from the outside, where they are in contact with oxygen, towards the inside.
Pi? ? large drop (formed from the atomization of diesel fuel) pi? time ? necessary for the flame front to reach the nucleus.
The time required ? such that, for durations of injection is very large and for high engine speeds (when the motor shaft runs through many corners in a short time) the relief valve is ? gi? open, by passing the droplets still in the process of combustion in the manifold.

[munro]

translated into layman's terms it means that if you inject after the tdc in the diesel fuel to burn,given its specifications and its combustion process,even with the exhaust valve closed and not finding enough oxygen,at this juncture,will not produce more heat and pressure?
and this is the end of the combustion on the inside of the micro particles of diesel only out of the cylinder,that is, the manifolds and the turbine, why? c'? the more air?? sorry doc, and the temperature is very high that the very first has triggered the combustion in this process,always with the discharge valve closed, and then heat and pressure are enclosed all in the cylinder,it has no influence in this thermodynamic cycle??with the post-injections,trattenedo all the heat and the press in the cylinder,in practice, we cannot "model" the thermodynamic cycle at our convenience, to try to prolong,as much as possible until it opens the exhaust valve "to break the eggs in the basket, "the phase of the useful" of the engine??

[dott.chem]

translated into layman's terms it means that if you inject after the tdc in the diesel fuel to burn,given its specifications and its combustion process,even with the exhaust valve closed and not finding enough oxygen,at this juncture,will not produce more heat and pressure?

I hope I interpret the question.
It will produce?, but with a yield very very low, and with no contraindications, important.
The oxygen, even if in excess ? able to relieve the problem, not solve it.

and this is the end of the combustion on the inside of the micro particles of diesel only out of the cylinder,that is, the manifolds and the turbine, why? c'? the more air??

No, not why? c'? pi? air to where it was before, simply because? the "drop" exhaust in the combustion in those times.

sorry doc, and the temperature is very high that the very first triggered the combustion in this process,always with the discharge valve closed, and then heat and pressure are enclosed all in the cylinder,and has no influence on the thermodynamic cycle??

That heat, as you say, it serves to trigger the combustion process. It is one of the parameters which I wrote before, it depends on the speed? a rection. I would not want to enter too much in details, but in the specific, is changed to the factor pre-exponential of the "constant reaction kinetics".
And as if by increasing the temperature the better the trigger. But there? is worth at the beginning of the injection, while you can not improve the initiation of a reaction already? primed... don't you think?

with the post-injections,trattenedo all the heat and the press in the cylinder,in practice, we cannot "model" the thermodynamic cycle to our liking for to try to extend,as much as possible until it opens the exhaust valve "to break the eggs in the basket "phase useful" of the engine??

When the duration of injection ? very long (see the full load, and, a fortiori, for cars developed there? not ? can or maybe ? better to say that with the means at our disposal do not think it is feasible

[munro]

That heat, as you say, it serves to trigger the combustion process. It is one of the parameters which I wrote before, it depends on the speed? a rection. I would not want to enter too much in details, but in the specific, is changed to the factor pre-exponential of the "constant reaction kinetics".
And as if by increasing the temperature the better the trigger. But there? is worth at the beginning of the injection, while you can not improve the initiation of a reaction already? primed... don't you think?

doc-I'm sorry, I don't want to break the bales but we discuss so try to understand as much as possible and all the answers you have reported this ? that the less I understand...i.e. leaving for a atimo lose the diesel engine and talking about the reaction already triggered your example that you can't? improve I immediately think of the atomic bomb..the cio? to trigger this weapon is tremendous made of plutonium and uranium,which I remember explodes in "free air", serves as a primer of tnt to start the process...bh? in this case, the tnt that triggers further cleaning procedures chain is literally "outclassed" from the plutonium in the bomb...
why this not ? you can in the engine?? the cio? for example, the americans in their drag top fuel used to mix with the methanol of the nitroglycerin from where to get the nitromethane..according to me, the methanol in this case it triggers the charge, but the nitro power just like the example of the bomb...why not ? can do the same with the diesel that once vaporized at high pressure in contact with high temperatures already triggered it will continue? to release heat and pressure?? and as if to a fire to put it as "chris" adding diesel fuel, the result would be a fire even more great and powerful of that? if it were not for the drain valve, open the "tank"(the cylinder) the engine would explode..but why not to check this explosion with the multiniezioni to have as much as said?