Stirling Engine

Steam Engine

Relevant Resource questions :

Concepts demonstrated :

• thermal expansion
• conversion of heat to work
• efficiency
• PV cycle
• Carnot cycle (Lec Dem computer file lists this demo under Carnot cycle)

Equipment needed :

• Horizontal mounted stirling engine
• candle
• matches
• CCD camera

• Light candle and place under horizontal piston of the stirling engine. i
• The engine will start to operate after approximately one minute.(The engine may need a kick start.) i
• A CCD camera may be needed if the demonstration is in a lecture theatre.

None.

Physics involved

This engine contains a gas in a closed system. ie fuel does not enter and exhaust does not leave. The energy source (heat) is external to the cylinders.

Thermal expansion (heating) of air in chamber A causes the overall pressure to increase thereby moving piston B up. In doing so A moves down, hot air goes into the cold chamber and decreases in volume (due to cooling). B then moves down to repeat the cycle.

See experiment Stirling Engine for more details. How to use the Demonstration :

• Use to demonstrate a closed engine.
• Use to show conversion of heat to mechanical energy.
• Discuss other types of engines.
• It may be used with experiments 4, 5 and 14.

Things to do or add :

• Upgrade the apparatus to display PVT data on a computer screen. ie finish the project already started with the students.