INTRODUCTION : A stirling engine is a heat engine operating by cyclic

compression and expansion of air or other gas, the

working fluid ,at different temperature levels such that

there is a net conversion of heat energy to mechanical

work.

The engine was first invented in 1816 by “ROBERT STIRLING” so its name came to be stirling engine.

BASIC WORKING PRINCIPLE : The main and the most basic principle underlying the

working of a Stirling engine is “DIFFERENCE OF “DIFFERENCE OF

TEMPERATURE ON TWO SIDES OF CYLINDER OF THE TEMPERATURE ON TWO SIDES OF CYLINDER OF THE

STIRLING ENGINE”STIRLING ENGINE”

Every stirling engine has a sealed cylinder with one part hot

and the other cold.

The working gas inside the engine is moved by a

mechanism from the hot side to cold side.

When gas is on the hotter side it expands and pushes up on

a piston and vice-versa.

VIEW OF PROTOTYPE OF STIRLING ENGINE

//

/---

The idealistic Stirling Engine consist of four basic thermodynamic processes acting on fluid:

1. Isothermal expansion.2. Constant volume heat removal.3. Isothermal compression.4. Constant volume heat addition.

PROCESSES INVOLVED IN AN STIRLING CYCLE :

1.ISOTHERMAL EXPANSION.

2.CONSTANT VOLUME HEAT REMOVAL.

3.ISOTHERMAL COMPRESSION.

4.CONSTANT VOLUME HEAT ADDITION.

The alpha configuration There are two cylinders.

The expansion cylinder (red) is maintained at a high temperature

while the compression cylinder (blue) is cooled.

The passage between the two cylinders contains the regenerator.

Beta type Stirling engine There is only one cylinder,

hot at one end and cold at the other.

A loose fitting displacer shunts the air between the hot and cold ends of the cylinder.

A power piston at the end of the cylinder drives the flywheel.

The gamma configuration

The Stirling gamma configuration is simply a Stirling beta engine in which the power piston is not mounted coaxially with the displacer piston but in a separate cylinder.

This avoids the complications of the of the displacer piston linkage passing through the power piston.

APPLICATIONS OF STIRLING ENGINES:Stirling engine is used in the following ways :1. In submarines2. In room or space for cooling3. In aero planes where the air gets cooled at higher

altitudes.4. In yatches where silence is valued5. As heat pump as it works irreversible cycle.