how fuel is burnt

[niky]

Originally Posted by peterrr

If you have only so much fuel to burn and you want to introduce water vapour in the process it is countereffective to use the fuel to make the water boil and convert it into steam. Air cooled LPG engines also use the exhaust heat to vaporise LPG

Water cooled LPG engine uses exhaust heat to vaporize LPG.

Originally Posted by RedDevil

What do you want? Who are you? Why do you post here?

Contextual bot?

Time traveller?

Medium channeling Tesla? (though the signal to noise ratio is poor)

[RedDevil]

Originally Posted by peterrr

look at the picture and weep

You must regard the premises under which you can use information from the InTech site...

Originally Posted by InTech

How to link

Our authors have produced a large number of scholarly papers and we would like to enable our website visitors to link and share that material.
It's free for everyone, everywhere in the world, as long as it is referenced and backlinked. If you would like to share this publication on your website or blog, please use the following HTML code: (etc)

See the page that came from: Gasoline Direct Injection - How to Link and Reference | InTechOpen

[peterrr]

I just want to give you some insight in how fuel is burned , it would give some insight on how to burn it better. The reason that it can be burned better is that car makers have not understood what is going on. They only made the symptoms go away. Many groups of people think they are making HHO gas, while the only thing they do is make water vapour. But as their cars have a better fuel economy they think it is true. I only wanted to post a an article that will give some insight in how gasoline is burned. but if you want me out of her i'll leave. Bye

[2000mc]

It's cool enough to condense in an engine that is a compresion ignition? I thought the temps were far to high as it self ignites

[RedDevil]

Originally Posted by peterrr

I just want to give you some insight in how fuel is burned (...) but if you want me out of her i'll leave. Bye

If you try to make me feel guilty for chasing you away from this forum by asking who you are and why you post here, or by disproving some of your claims, then think again.

Introduce yourself properly and adhere to forum etiquette and general good manners.
If you make bold claims be sure to have some backing.
Remember that freedom of speech applies to all, not just you. And an obligation to listen applies to none.

So it is up to you.
If you stay and try to be an useful member of this community, then, by all means, welcome.
If not, fine. You won't make me weep.

[Cycle]

Yeah, freedom of speech applies to all... so who gave you the authority to question why he's posting?

I see exactly what he's saying... the small size of the squish area, combined with the average motility of even the largest fuel molecules, combined with pressure being higher than the condensation point of some of those fuel molecules, combined with the relatively cooler surfaces of the liquid-cooled head means some of the fuel will condense on the surface (probably not just the head... most likely also on the cylinder wall above the top ring... which, if you'll remember, is a significant contributor to UBHC emissions).

By injecting water vapor, which has a lower condensation point than the fuel, the water will condense on the surfaces before the fuel will. When the fuel condenses, it's sitting on top of the water molecules. As the water flashes to steam due to the advancing flame front, it pushes that unburnt fuel back into the flame front, thereby burning it.

In fact, that's exactly what I've been thinking. I'll be dropping a new ECU into my bike to control water heating and injection to test this, after I get the new ceramic-coated head and piston in, which will take place directly after I get done putting the new hybrid ceramic bearings and taller rear gears in.

As for his stating that most of the fuel burning takes place after TDC, he's yet again correct. Most of the fuel burning (and hence expansion) takes place after TDC. If it didn't, there'd be no available power. Or weren't you aware that engines are specifically designed such that maximum expansion takes place from 20 to 45 degrees ATDC (depending upon the engine), to maximize the mechanical efficiency of the pressure pushing against the piston? That is, after all, why pressure peaks ATDC.

Think about it... if, say, 55% of fuel were burned BTDC, and hence 55% of expansion took place BTDC, the engine would have to extract flywheel energy to overcome that expansion... it's not contributing to driving the flywheel in the correct rotational direction.

The last 45% of fuel burn (and hence expansion) would contribute to driving the flywheel in the correct rotational direction... except you've now got a 10% energy deficit at the flywheel.

Perhaps if you unblinded your eyes and learned simple math, you'd realize these things... and hence you'd not feel compelled to question those such as Peter who apparently have a firmer grasp upon the basics of combustion than you. And you'd not be so nasty to them that you then ran them off the forum.

Perhaps it's you who should go... do apologize to Peter and invite him back when you do so.

HTH, HAND

Oh, look:
MOTOR Magazine Article | MOTOR Information Systems
"Heat transferred to the induction charge should be enough only to improve evaporation of the fuel to avoid condensation on the bore walls."

Oh, look:
Cylinder head design
"The wedge-shaped combustion chamber tapers away from the plug which is at the thick end of the wedge. The valves are in line and inclined from the vertical. This design usually has a smaller surface area than the others, with less area where fuel droplets can condense. Less fuel is left unburned after combustion, which reduces hydrocarbon exhaust emissions."

Seems someone owes someone an apology for being too dense to understand what someone was talking about, instead lashing out and driving away an innovative thinker from the forum.

Of course, Peter not only showed you the graph of fuel burn rate per degree, he also did the math for you to show you why fuel molecules can condense... and you still didn't get it. So I expect you'll try kicking like a mule again.

[RedDevil]

Originally Posted by Cycle

Yeah, freedom of speech applies to all... so who gave you the authority to question why he's posting?
...
Seems someone owes someone an apology for being too dense to understand what someone was talking about, instead lashing out and driving away an innovative thinker from the forum.

Of course, Peter not only showed you the graph of fuel burn rate per degree, he also did the math for you to show you why fuel molecules can condense... and you still didn't get it. So I expect you'll try kicking like a mule again.

Hey! Do I need to be authorized to ask that? I guess not.
There was enough in his posts that was clearly untrue, as I've shown with the links to neutral info on that subject.

Instead of addressing that matter he got nasty.
As a fellow Dutchman I felt ashamed for his behaviour. Call it national pride, I thought he should have introduced himself at the very least.
Maybe my asking for who he was sounded terse, but it was not an insult by any means.

Then again, he did not come round to introduce himself.
He just sent me a short PM asking how to get rid of the ecomodder mail notifications (I PM-ed him back explaining how to do that) and then he posted his last reply, threatening to leave and all.

But according to you I need to apologize, am too dense to understand what Peterrr wrote (even though a lot of that was clearly wrong) and kick like a mule, chasing innovative thinkers away.

Well then, this forum has a mechanism to punish trolls like me.
Click on the small triangle on the left and report my post, describe why you think my post breaks forum etiquette and the moderators will send me a warning or even ban me.

As for now, I will not apologize.
In my eyes Peterrr's conduct was unacceptable even if he were an innovative thinker.
His decision to stop posting was his own, and probably best for all.

[RedDevil]

Originally Posted by Cycle

As for his stating that most of the fuel burning takes place after TDC, he's yet again correct. Most of the fuel burning (and hence expansion) takes place after TDC. If it didn't, there'd be no available power.

This has been proven wrong before, but here goes:

When fuel gets burned it produces a lot of pressurised exhaust gas and heat.
The pressure is what drives the piston down in the expansion phase.
It will do that for all of the expansion phase.

The pressure rises sharply when the ignition takes place just before TDC, and that will indeed slow down the engine a little bit.
But the pressure is still there when the piston moves past TDC, and will stay there until it gets released in the exhaust phase.
Ideally you'd burn all the fuel the instant the engine is a TDC so none of it hinders the compression phase and all of it aids the expansion phase.

The heat just increases the pressure, it also heats up the pistons and cylinder walls so that the fuel won't condensate on them once the engine is at operating temperature.

[Cycle]

Wow, LOL... a quick post-hump and two posts... but you're not defensive about having driven off someone from the forum, right?

Originally Posted by RedDevil

Hey! Do I need to be authorized to ask that? I guess not.

Unless you're a moderator or admin, you do not have the right to question why someone is here. Who died and made you king?

Originally Posted by RedDevil

There was enough in his posts that was clearly untrue, as I've shown with the links to neutral info on that subject.

And he backed up his data with corroborable data from third parties and with math that obviously escaped you.

Originally Posted by RedDevil

Instead of addressing that matter he got nasty.

Where, exactly, was that? I read the entire thread... the nastiest he got was telling you to "read it and weep" in providing you with the fuel burn per crankshaft degree chart... which obviously escaped you.

Originally Posted by RedDevil

As a fellow Dutchman I felt ashamed for his behaviour.

Yet you feel no shame for you own. LOL

Originally Posted by RedDevil

Call it national pride, I thought he should have introduced himself at the very least.

Why? Does your knowing him make the pertinent, informative and accurate data he provided any more relevant?

Originally Posted by RedDevil

Maybe my asking for who he was sounded terse, but it was not an insult by any means.

No, but your asking "Who are you, why are you posting here?" most certainly was, by any stretch of common civility. And the fact that you're here, post-humping in mere minutes while getting defensive in not one, but two replies shows you know that to be a fact.

Originally Posted by RedDevil

Then again, he did not come round to introduce himself.

Nor have I. Should I vacate the premises, as well? Do the admins and moderators know you've taken it upon yourself to run off anyone not following your rules?

Originally Posted by RedDevil

He just sent me a short PM asking how to get rid of the ecomodder mail notifications (I PM-ed him back explaining how to do that) and then he posted his last reply, threatening to leave and all.

But according to you I need to apologize, am too dense to understand what Peterrr wrote (even though a lot of that was clearly wrong) and kick like a mule, chasing innovative thinkers away.

Which part of the math that he provided, exactly, is incorrect? Which part of that third-party provided chart is incorrect? Which part of fuel can condense on the cylinder head (which is part of the reason for the design of wedge-shaped heads, after all) is incorrect?

Originally Posted by RedDevil

Well then, this forum has a mechanism to punish trolls like me.
Click on the small triangle on the left and report my post, describe why you think my post breaks forum etiquette and the moderators will send me a warning or even ban me.

No, I think I'll just beat you about the head and shoulders for a while longer with facts, truth and reality... you apparently require a stronger dose. LOL

Originally Posted by RedDevil

As for now, I will not apologize.
In my eyes Peterrr's conduct was unacceptable even if he were an innovative thinker.
His decision to stop posting was his own, and probably best for all.

And yet, you see no problem with imposing your rules upon others, despite your not being an admin or moderator. Hypocrisy, thy name is RedDevil. LOL

I especially like this, your quote:

Originally Posted by RedDevil

"As for now, in a moving application like a car, there is no effective way to use exhaust heat except for heating the cabin area with an air cooled engine."

Ummm, how about:
Heat the water to just below its in-cylinder latent heat of vaporization at the appropriate pressure such that it condenses first as cylinder pressure rises, thus coating the cylinder wall above the top ring and the head with water, thus blocking the fuel from coating those surfaces and blowing that unburnt fuel back into the flame front as quickly as possible when that water, being so close to its latent heat of vaporization temperature, reflashes to steam as the flame front passes, thereby improving efficiency by not using as much in-cylinder heat to cause said water flashing, and thereby maximizing the amount of water injected thus adding to cylinder pressure and thus engine power?

Think you can suss all that out? LOL

[Cycle]

Originally Posted by RedDevil

This has been proven wrong before, but here goes:

When fuel gets burned it produces a lot of pressurised exhaust gas and heat.
The pressure is what drives the piston down in the expansion phase.
It will do that for all of the expansion phase.

The pressure rises sharply when the ignition takes place just before TDC, and that will indeed slow down the engine a little bit.
But the pressure is still there when the piston moves past TDC, and will stay there until it gets released in the exhaust phase.

The heat just increases the pressure, it also heats up the pistons and cylinder walls so that the fuel won't condensate on them once the engine is at operating temperature.

You apparently have such a flimsy grasp on the subject that you're not aware that pressure immediately follows combustion... do you suppose to tell everyone that somehow the flame front travels through the majority of the fuel BTDC, yet the pressure rise somehow magically waits until the convenient point ATDC? LOL

You apparently missed this in my previous post, so I'll provide it again:
Cylinder head design
"The wedge-shaped combustion chamber tapers away from the plug which is at the thick end of the wedge. The valves are in line and inclined from the vertical. This design usually has a smaller surface area than the others, with less area where fuel droplets can condense. Less fuel is left unburned after combustion, which reduces hydrocarbon exhaust emissions."

Do you suppose to tell everyone that fuel droplet condensation only occurs at startup, and hence the manufacturers would undertake to design an entire head just to mitigate a problem that lasts for that short warm-up interval? LOL