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Hi everyone. Some years ago I read about the Crower six cycle engine. Always wanted to understand it better. And now is the time to follow up on that desire.
I’m trying to calculate what happens during the water injection. The goal is to determine the conditions (pressure, temperature) after water injection and before the second expansion / power stroke.
On an intuitive level here’s what I think is happening:
1) The hot air heats the injected water to its boiling point. (above 100C, as determined by the cylinder pressure.)
2) Heating the water cools the air, and reduces the pressure accordingly.
3) The hot air then vaporizes the liquid water, causing two things to happen:
o The air is further cooled by the water’s heat of vaporization (which also reduces the cylinder pressure), and
o The newly formed steam expands greatly, causing the pressure and temperature to increase.
There’s always assumptions. Here are mine:
* To keep things simple, the cylinder starts with hot compressed air instead of combustion exhaust (CO2, steam, and who knows what else). Perhaps I’ll revisit this later.
* The amount of liquid water injected is small. The air displaced by the water is small enough to ignore any pressure increase.
Currently I can calculate steps #1 and #2, but Step #3 has me stumped and befuddled. Perhaps you can walk me through how to get the resulting conditions. Links to previously worked out problems would be great also.
Thanks for your help!
I’m trying to calculate what happens during the water injection. The goal is to determine the conditions (pressure, temperature) after water injection and before the second expansion / power stroke.
On an intuitive level here’s what I think is happening:
1) The hot air heats the injected water to its boiling point. (above 100C, as determined by the cylinder pressure.)
2) Heating the water cools the air, and reduces the pressure accordingly.
3) The hot air then vaporizes the liquid water, causing two things to happen:
o The air is further cooled by the water’s heat of vaporization (which also reduces the cylinder pressure), and
o The newly formed steam expands greatly, causing the pressure and temperature to increase.
There’s always assumptions. Here are mine:
* To keep things simple, the cylinder starts with hot compressed air instead of combustion exhaust (CO2, steam, and who knows what else). Perhaps I’ll revisit this later.
* The amount of liquid water injected is small. The air displaced by the water is small enough to ignore any pressure increase.
Currently I can calculate steps #1 and #2, but Step #3 has me stumped and befuddled. Perhaps you can walk me through how to get the resulting conditions. Links to previously worked out problems would be great also.
Thanks for your help!
