Thought experiment

[NickTF]

Man if no smoke is good i'm doomed lol

[Drasko]

This guy must work for banks lmao!!!

word of advice 300D, banks is bunk and no smoke will not make you the power we all play with hear at the amazing compD. Perhaps you dont undersdtand correct tuning and what needs to be done to make big power? Think what you will but IMO, youre pretty far off to be making comments like you have.

[copenglenn]

You don't need big power in a transit bus lol.

[NickTF]

Originally Posted by copenglenn

You don't need big power in a transit bus lol.

I don't know I heard one lay some wheel in Ocean City one summer lmao

[Drasko]

Chit, you ever got a ride on the blue or red busses at KCI coming from the economy parking lots copenglen? lmao

Theyre almost scary!

[copenglenn]

Originally Posted by Drasko

Chit, you ever got a ride on the blue or red busses at KCI coming from the economy parking lots copenglen? lmao

Theyre almost scary!

Hell yeah, its not so much the bus but its the driver lol.

[Drasko]

where you at copen? im up in edgerton

[copenglenn]

I'm down in Paola. I work in Gardner.

[kazairl]

Originally Posted by 300D

Science and real world use.

Preferably something I can read. I would rather make up my own mind than rely on you to tell me how it is.

[Begle1]

And Begle1 has yet to find anybody willing or capable to write a little narrative on what water does in the intake manifold and continues to do in the cylinder.

It has to do something different in the cylinder...

[ENafziger]

And Begle1 has yet to find anybody willing or capable to write a little narrative on what water does in the intake manifold and continues to do in the cylinder.

It has to do something different in the cylinder...

Well, here's my answer.

Short history. We're running a very highly instrumented research engine at work. Everything you could think of is controlled and measured. We run the exact same start-up scheme every day, run through the same initial engine health check points, etc. Test procedures remove effects of path dependance, etc.

The engine is turbocharged, but not with turbomachinery. To more exactly control conditions, and eliminate the boundaries of turbomachinery, we are using a very large air compressor, filters, air driers, heaters, and an air nozzle handling unit to control air mass flow, air temperature, pressure, and humidity to the engine.

Recently, the air drier unit began malfunctioning. The humidity of the intake air went up considerably. The effect of higher humidity was: IMEP went up slightly, combustion phasing (i.e. 50% mass fraction burned) was slightly retarded, peak cylinder pressure went down, and exhaust temperature was reduced. All the things you would want.

--Eric

[Joesixpack]

Originally Posted by ENafziger

Well, here's my answer.

Short history. We're running a very highly instrumented research engine at work. Everything you could think of is controlled and measured. We run the exact same start-up scheme every day, run through the same initial engine health check points, etc. Test procedures remove effects of path dependance, etc.

The engine is turbocharged, but not with turbomachinery. To more exactly control conditions, and eliminate the boundaries of turbomachinery, we are using a very large air compressor, filters, air driers, heaters, and an air nozzle handling unit to control air mass flow, air temperature, pressure, and humidity to the engine.

Recently, the air drier unit began malfunctioning. The humidity of the intake air went up considerably. The effect of higher humidity was: IMEP went up slightly, combustion phasing (i.e. 50% mass fraction burned) was slightly retarded, peak cylinder pressure went down, and exhaust temperature was reduced. All the things you would want.

--Eric

I would not expect an increase in IMEP with an increase in humidity....all else equal.

[ENafziger]

I would not expect an increase in IMEP with an increase in humidity....all else equal.

I wouldn't either!! However, while I believe the increase was real and was within measurement tolerances, it wouldn't be discernable by the seat-of-the-pants. If I remember right, the difference was 18.92 bar vs 19.07 bar. I'll try to pull the log files from the high speed daq if I get a chance.

One thing to note as well, is this included no cooling effect of the intake charge, as intake temperature was maintained constant. The only difference was in the humidity.

--Eric

[copenglenn]

I would think that intake tempatures would be decreased if they were cooled like in a IC situation where the water is injected pre cooler, or in your case before the refrigerated dryer.

[Kronic_187]

................. my whole take was water is H20.... hydrogen and oxygen...... burning it or "boiling" it in the cyclinder would in effect give somewhat the same effects as nos

you remeber the science experiments in grade 10 right.... but a match in an upside down beaker full of oxygen and get a pop... put a match in a tube of hydrogen and get a bang (or the other way around) either way... begle1 is obviasly on to sumthing, because only assholes are trying to prove a point in this thread, none of the bigger names have mentioned dick all yet.... we must shake the knowledge tree harder

[Begle1]

Originally Posted by ENafziger

Recently, the air drier unit began malfunctioning. The humidity of the intake air went up considerably. The effect of higher humidity was: IMEP went up slightly, combustion phasing (i.e. 50% mass fraction burned) was slightly retarded, peak cylinder pressure went down, and exhaust temperature was reduced. All the things you would want.
--Eric

So you have a test rig that can't replicate the gremlin, but it can replicate the gremlin's cousin...

I translate your jargon as "the temperature of the intake remained constant and the greater humidity caused a greater average cylinder pressure, slower-burning combustion, lower peak cylinder pressure and lower exhaust temperature". It'd make sense that a little thing you noticed with some added humidity could be a much more dramatic thing with a big water injection system.

Your data means that water in the cylinder does have a performance and cooling benefit above and beyond cooling the intake. How? Why? It seems like you have all the data to figure out what exactly it does in the cylinder, if the intuitive amongst us wanted to build a theory around it.

Originally Posted by Kronic_187

................. my whole take was water is H20.... hydrogen and oxygen...... burning it or "boiling" it in the cyclinder would in effect give somewhat the same effects as nos

you remeber the science experiments in grade 10 right.... but a match in an upside down beaker full of oxygen and get a pop... put a match in a tube of hydrogen and get a bang (or the other way around) either way... begle1 is obviasly on to sumthing, because only assholes are trying to prove a point in this thread, none of the bigger names have mentioned dick all yet.... we must shake the knowledge tree harder

While I don't pretend to know or even have a coherent theory of what water does in the cylinder, I see nothing that indicates it would break down to oxygen and hydrogen. Decomposition of water would require very high temperatures, electrical current, radiation or chemical reactions that as far as I know don't exist in an engine. It's possible a little bit of it happens due to some bizarre phenomenon, but any theory of operation claiming decomposition of water deserves a whole lot of skepticism.

[Kronic_187]

were in agreement that there is a possibility of there being a phasse change though..... from liquid to gas...... and if the droplets are atomized enough, with 1200-1500*F........\


see where im going

[ENafziger]

Interesting to play around with if you've not seen it before: Not2Fast: Turbo Calculator

--Eric

[Drasko]

Kronic, unless our motors are creating electricity in the cylinder, you wount get a molecular split. It take current and polarity to split the 2 so not, it wont have a nitrous effect although nitrous itself isnt an added fuel itself.

[awenthol]

Originally Posted by Begle1

So if we've established water in the cylinder has no benefit for performance, the next question is:

Does water in the cylinder lower EGT's above and beyond what water in the manifold does? If the small demon doesn't cause any more or less horsepower, does it cause higher or lower EGT's?

Water in the intake is merely an air condensor. Water in the cylinder = wasted energy (lose a lot of energy getting the water up to those very high combustion temps). So, the additional EGT reduction is generally coming at a performance cost, for said reason.

Going back to the water injection vs a cooler...the difference would be the effectiveness of the cooler (water/air to metal to air heat exchange) vs the effectiveness of the water (water to air exchange).