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
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