Physics of the Stirling Engine

A thesis on the power output of this wonderful mechanism

The elegance of the Stirling engine makes it an enduring object of study, as well as the perfect vehicle for learning the fundamentals of machining and fabrication.

For my undergraduate physics thesis, I elevated a simple, desktop model of a gamma-type Stirling engine into a refined, highly-adjustable test rig. I machined brass flywheels, a new crankshaft, and lightweight connecting rods to enable manipulation of the piston phase angle and swept volume ratio. I built a miniature Prony brake to measure the power output of the engine, and by comparing this real-world data to the predictions given by thermodynamic models, could optimize the performance of my little engine that could.

Desktop dyno testing

Coils of nichrome wire replace the alcohol flame as a controllable heat source, while a small box fan provides cooling. A delrin Prony brake records torque as a function of RPM, with power output a computation away. Dynamometer testing, miniaturized and on a student budget.

Close Menu