Low Temperature Stirling Engine

Low Temperature Stirling Engine

Equipment:

  • Low Temperature Stirling Engine
  • Coffee Cup
  • Tea Kettle
  • Water

Demo:

  1. Pour some hot water into a coffee cup
  2. Place the Stirling engine on top of the cup
  3. Wait 15 seconds and then spin the flywheel to start the engine cycle

Explanation:

Stirling engines work by cycling through four steps, which will be described below:

  1. Isothermal expansion: Most of the gas is first located at the end with the hot water, which is at a higher temperature compared to the rest of the engine. As the gas is heated by the water, the pressure rises and expands.
  2. Isochoric (constant volume) heat-removal: As the gas expands, it pushes the piston to continue spinning the flywheel. The volume remains constant while the hot gas moves toward the cooler part of the cup.
  3. Isothermal compression: At the cooler part of the cup, the gas is cooling and contracting, losing heat. This causes the gas to flow back to the hotter part of the cup.
  4. Isochoric heat-addition: At constant volume, the temperature of the gas increases since the cooled gas moves back to the hotter part of the cup, gaining heat once again. This starts the cycle back for the gas to undergo isothermal expansion.