Quote:
Originally Posted by drmiller100
how many grams of exhaust gas in the cylinder?
what is the expansion ratio of water to steam?
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What difference does it make? You completely missed the point.
Look, even if you injected 1% by mass of liquid water into the exhaust inside a combustion chamber when the piston is TDC, you're not going to get the result you think you're going to get, even if the water's near 100 C anyway.
That pesky latent heat of vaporization, that you keep neglecting, is going to cause the exhaust to cool off as the liquid water vaporizes. What's more, once water enters the vapor phase, it's a gas. It gets treated as a gas, and it behaves as a gas. It'll reach equilibrium temperature with the exhaust gas it's mixing with. The whole gas mixture will be at a lower pressure than would exist had the exhaust gas not been sprayed with liquid water, because the temperature dropped due to the water taking heat energy away from the exhaust gas in the process of becoming steam.
By the way, what's the pressure of steam at 100 C?
Quote:
Originally Posted by drmiller100
seems like if we are running "efficient" we are somewhere in the neighborhood of 14:1 air to fuel.
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Efficient part-throttle operation is actually around 17:1 with gasoline, which is why Lean Burn is so popular among those who are able to use it. The rest of us are not allowed to use it as a factory option because of the Clean Air Act of 1990. Try again.
Quote:
Originally Posted by drmiller100
If we run twice as much water as fuel, then our final ratio will be something like 7:1 water to exhaust gas (rounding a bit).
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Is this a guess, or is there something you can show? And you do realize that exhaust gas has water vapor in it, right?
Quote:
Originally Posted by drmiller100
one of the interesting things is our pumping losses go towards zero - if we get the water up close to 200 or so before we inject it, the "vacuum" of the intake will cause it to boil in the partial vacuum.
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Assuming that you mean to flood the intake manifold with steam, then yes, pumping losses do approach zero. However, that's because you're diluting the intake charge with an inert gas (water vapor), thereby forcing the throttle to open up to maintain the same oxygen intake, not because of any magical properties of water becoming steam inside a combustion chamber.
Quote:
Originally Posted by drmiller100
my schooling was more theoretical and less train driver driven.
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This much is also obvious. You keep on with your "thought experiments" and such, never bothering to once run actual experiments to see if your ideas might actually work. Philosophers run thought experiments. Engineers work with reality.