Heat Engine Processes
| Cycle | Process 1-2 (Compression) |
Process 2-3 (Heat Addition) |
Process 3-4 (Expansion) |
Process 4-1 (Heat Rejection) |
Notes |
|---|---|---|---|---|---|
| Power cycles normally with external combustion - or heat pump cycles: | |||||
| Bell Coleman | adiabatic | isobaric | adiabatic | isobaric | A reversed Brayton cycle |
| Carnot | isentropic | isothermal | isentropic | isothermal | |
| Ericsson | isothermal | isobaric | isothermal | isobaric | the second Ericsson cycle from 1853 |
| Rankine | adiabatic | isobaric | adiabatic | isobaric | Steam engine |
| Scuderi | adiabatic | variable pressure and volume |
adiabatic | isochoric | |
| Stirling | isothermal | isochoric | isothermal | isochoric | |
| Stoddard | adiabatic | isobaric | adiabatic | isobaric | |
Power cycles normally with internal combustion: |
|||||
| Brayton | adiabatic | isobaric | adiabatic | isobaric | Jet engines the external combustion version of this cycle is known as first Ericsson cycle from 1833 |
| Diesel | adiabatic | isobaric | adiabatic | isochoric | |
| Lenoir | isobaric | isochoric | adiabatic | Pulse jets (Note: Process 1-2 accomplishes both the heat rejection and the compression) |
|
| Otto | adiabatic | isochoric | adiabatic | isochoric | Gasoline / petrol engines |
Each process is one of the following:
- isothermal (at constant temperature, maintained with heat added or removed from a heat source or sink)
- isobaric (at constant pressure)
- isometric/isochoric (at constant volume), also referred to as iso-volumetric
- adiabatic (no heat is added or removed from the system during adiabatic process which is equivalent to saying that the entropy remains constant, if the process is also reversible.)
Read more about this topic: Heat Engine
Famous quotes containing the words heat, engine and/or processes:
“... often in the heat of noonday, leaning on a hoe, looking across valleys at the mountains, so blue, so close, my only conscious thought was, “How can I ever get away from here? How can I get to where they have books, where I can be educated?” I worked hard, always waiting for something to happen to change things. There came a time when I knew I must make them happen; that no one would do anything about it for me. And I did.”
—Belinda Jelliffe (1892–1979)
“There is a small steam engine in his brain which not only sets the cerebral mass in motion, but keeps the owner in hot water.”
—Unknown. New York Weekly Mirror (July 5, 1845)
“Our bodies are shaped to bear children, and our lives are a working out of the processes of creation. All our ambitions and intelligence are beside that great elemental point.”
—Phyllis McGinley (1905–1978)