Carnot Heat Engine

Carnot Heat Engine brings classical thermodynamics to life by pairing an animated 3D piston-cylinder-flywheel assembly with a synchronized 3D Pressure-Volume (P-V) diagram. Students can drag the piston head to scrub through the cycle or click any of the four corner states: Isothermal Expansion in contact with the hot reservoir T_H, Adiabatic Expansion to T_C, Isothermal Compression in contact with the cold reservoir T_C, and Adiabatic Compression back to T_H. Gas molecules speed up and slow down with temperature while live readouts report Carnot efficiency eta = 1 - T_C / T_H, gas temperature, pressure, and net work per cycle.

• Click each of the four corner nodes on the P-V loop to step through Isothermal Expansion, Adiabatic Expansion, Isothermal Compression, and Adiabatic Compression.
• Raise Hot reservoir T_H from 500 K to 900 K while keeping T_C at 300 K, and watch the enclosed P-V loop area and Carnot efficiency eta grow.
• Lower Cold reservoir T_C from 400 K to 200 K and verify that cooling the exhaust sink increases efficiency even more effectively than raising T_H by the same amount.
• Drag the piston head up and down by hand and observe how the thermal bridge beneath the cylinder switches between T_H, insulated, and T_C.
• Increase the Isothermal expansion ratio and notice that Net work per cycle increases while the theoretical Carnot efficiency percentage stays unchanged.

1. 1Identify the four reversible processes that make up the Carnot heat engine cycle on a P-V diagram.
2. 2Calculate the maximum theoretical efficiency of any heat engine using eta = 1 - T_C / T_H.
3. 3Distinguish between isothermal strokes (constant temperature, heat transfer) and adiabatic strokes (insulated, temperature changes via work).
4. 4Explain why the area enclosed inside the P-V loop represents the net mechanical work output per cycle.

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