|
Dang it. I typed in a big old long response, and hit the delete key.
Ok. So, again Thank You Mort. I think I follow most of this, but am starting to get lost.
So, I want to make sure I have the basic principals correct.
Lets look at three cases - all without fuel.
Case one is wide open throttle, case two is 5 psi absolute, and case three is the same grams of air as case two, plus enough "steam" to make the pressure atmospheric.
Assume all three are the same "temperature".
On the intake stroke, the cylinder takes a gulp, which takes some work in case two. Then there is the compression stroke, and then the powerstroke. My understanding is the all three cases will have the same net work completed for the compression and power stroke - zero.
Now I realize we will lose some heat to the piston and cylinder, but other than the lost heat, no net work. am I correct?
from there. In case two, assume we add the "right" amount of fuel, which is also the right amount of fuel for case three.
Case two will have much higher temperatures then case three. There is more mass in the steam to heat up.
Now maybe this is what you wrote above, and maybe your conclusion was it is half as efficient with the steam than without.
But what about heat loss to the cylinders and heads? lower absolute temps will have less heat loss to pistons and heads.
Is this significant?
Again, thanks for your patience.
|