The Robert Stirling Invention

In 1816 Robert Stirling invented an engine that is much different than the engine in your car. The Stirling engine has the potential to be much more efficient than gasoline or diesel engines, although today it is primarily used in specialized items that focus on quiet operation such as a submarine.

What makes this engine different than the internal-combustion engines in cars is that it utilizes the Stirling cycle. During the Stirling cycle process, gasses never leave the engine, as there are no exhaust valves and results in a very quiet engine. The Stirling cycle uses an external heat source such as gasoline, solar energy, or even the heat produced by the combustion of decaying plants.

To explain how the Stirling cycle works, there is an important key principle. A fixed amount of gas is sealed inside the engine and the cycle involves changing the pressure of this gas inside the gas. A fixed amount of gas in a fixed amount of space combined with a rising temperature, pressure will increase while the opposite with cause the pressure to decrease.

Stirling engines have a sealed cylinder with one part that is hot and one that is cold. The working gas contained inside of the engine is moved from the hot side to the cold side by a mechanism. When the gas is on the hot side, it expands and pushes a piston then it moves back to the cold side and contracts. There are different types of Stirling engines and the more common types are the two-piston type Stirling engine and the displacer type Stirling engine.

The displacer type Stirling Engine is continuously heated by a heat source on the space below the displacer piston while the space above the displacer piston is continuously cooled. Below is an animation to explain this type.

The two-piston type animation is shown below demonstrating the space above the hot piston is continuously heated by a heat source while the space above the cold piston is continuously cooled.

Stirling engines are not more common because of the impracticality of use in most items. With the heat source being external, the engine encounters some delays when responding to changes in the amount of heat being applied, which caused the engine to require some time to warm up before it can produce power and the engine is not capable of changing the amount of power output quickly.

Works Cited

"American Stirling Company." American Stirling Company. N.p., n.d. Web. 27 Oct. 2013. <http://www.stirlingengine.com>.

"How Stirling Engines Work." HowStuffWorks. N.p., n.d. Web. 27 Oct. 2013. <http://auto.howstuffworks.com/stirling-engine1.htm>.

"Stirling Engine Home Page -English-." Stirling Engine Home Page -English-. N.p., n.d. Web. 27 Oct. 2013. <http://www.bekkoame.ne.jp/~khirata/indexe.htm>.

"Stirling Engine Society USA." Stirling Engine Society USA. N.p., n.d. Web. 27 Oct. 2013

            <http://www.sesusa.org>.