🌡️ Stirling Engine Simulator
The Stirling engine runs on two isothermal and two isochoric processes. With a perfect regenerator its efficiency equals the Carnot limit η = 1 − Tc/Th. Trace the cycle on the P-V diagram.
Reservoirs
Current Stage
Stirling Efficiency
Energy Budget (J)
State Point
What It Demonstrates
The Stirling cycle has four stages: (1) isothermal expansion at Th — heat absorbed from hot source; (2) isochoric cooling through the regenerator — heat stored; (3) isothermal compression at Tc — heat rejected to cold sink; (4) isochoric heating through the regenerator — stored heat returned. The regenerator is the key innovation: it eliminates heat waste between the constant-volume stages, making the theoretical efficiency equal to Carnot's.
How to Use
- Adjust Th and Tc to change reservoir temperatures
- Adjust volume ratio r to scale the cycle
- The yellow dashed lines are the isochoric stages; coloured curves are isothermals
- Compare the enclosed area (net work) with the Carnot cycle for the same temperatures
Did You Know?
Invented by Robert Stirling in 1816, the Stirling engine is currently being used in submarines, cryocoolers, solar dish generators, and space probe RTGs. Its quiet operation, high theoretical efficiency, and ability to run on any heat source (including waste heat or sunlight) make it attractive for renewable energy applications.