# Quantitative Stirling Cycle Measurements: P-V Diagram and Refrigeration

## TL;DR

This paper presents simple modifications to a demonstration Stirling engine enabling quantitative P-V diagram measurements and explores its refrigeration capability by measuring temperature differences.

## Contribution

It introduces accessible methods for measuring Stirling cycle parameters and demonstrates the engine's refrigeration function through practical modifications.

## Key findings

- Successful measurement of P-V diagram using inexpensive sensors
- Engine can operate as a refrigerator with measurable temperature difference
- Demonstrates practical modifications for educational purposes

## Abstract

This paper describes simple modifications to a demonstration Stirling engine that allows one to make quantitative measurements of the Stirling cycle. First, we describe measurements of the $P$-$V$ diagram using an inexpensive pressure sensor and a common photogate. Then, as a supplement, the engine was run as a refrigerator by using a rotary tool to turn the flywheel of the engine. A small, but measurable, temperature difference developed across the body of the engine.