Thermodynamic Cycles & Entropy
Carnot · Otto · Stirling cycles · PV diagram and entropy production
CYCLE
Carnot
Otto
Stirling
TEMPERATURES
T_hot (K)
800
T_cold (K)
300
Compression ratio
8
γ (heat cap. ratio)
1.40
RESULTS
Efficiency η
—
η_Carnot
—
W_net
—
Q_hot
—
ΔS_universe
—
2nd Law:
ΔS_universe ≥ 0
Carnot:
Reversible — maximum efficiency η=1−T_c/T_h. ΔS=0.
Otto:
Gasoline engine cycle. Irreversible heat addition at constant volume → ΔS > 0.
Stirling:
Ideal Stirling has regenerator recovering heat — can approach Carnot efficiency. Piston animation shows phase-shifted pistons.
ANIMATION
Speed
1.0