____________________ |\ PPPPPPPPPPPPPPPPPPPP | T T | 4 T | 1 4 T | 1 T | 1 4 T PVT surface air ^ | 1 T /|\ | 1 4 T | | T 2 4 T Pres | T 2 3 | T 2 3 \ T T \ T T \ T T \ T T \ | \ T T _\| \ T T Vol \ VVVVVVVVVVVVVVVVVVVVV \ | | \|___________________| <--- Temp 1 2 3 4 || || || || || || || || || || || || ||__||__|| || || || || || ||__||__|| ||______|| ||__||__|| || || || ||______|| || || ||______|| ||__||__|| || || || ^ || || || ||______|| || ^ || || | || || | || || | || || | || || | || || v || || v || ||______|| ||______|| ||______|| ||______|| |________| |________| |________| |________| Isothermal Adiabatic Isothermal Adiabatic expansion expansion compression compression high temp low temp Carnot cycle