What is a stirling engine?
1) “A Stirling engine is a kind of heat engine that converts heat into useful mechanical energy by the movement of a piston inside a cylinder within the engine. Unlike other commonly found heat engines such as the internal combustion engine used in cars and the steam engine used on railways, it re-uses the same gas for each stroke of the piston so there is no noisy exhaust. The same gas is repeatedly heated and cooled within the engine’s cylinder. To run it needs a supply of heat to heat its hot parts. This can come from a fire, but also from the sun’s rays, from hot rocks near a volcano or from nuclear energy. It also has cold parts which cool the gas inside it and these are kept cold by a stream of air or water flowing over them. It was invented by a Scottish minister, Reverend Dr. Robert Stirling in 1816.” Source and further information: http://simple.wikipedia.org/wiki/Stirling_engine 2) “
Like the gasoline, diesel, and jet engines with which we are all familiar, the Stirling is a heat engine; that is, an engine that derives its power from heat. But unlike those other engines, the Stirling obtains its heat from outside, rather than inside, the working cylinders. In this respect, the Stirling is similar to that charming old workhorse of the industrial revolution, the steam engine. This difference, between external and internal combustion, is one of the main reasons for the widespread current interest in the Stirling. An internal combustion engine, that is an engine that burns its fuel inside its working cylinders or chambers like the gasoline, diesel, or gas turbine engine, is generally rather particular about its fuel. A gasoline engine may be modified to run on hydrogen, methane, or propane; but it will not run on salad oil, straw, coal, or peat. When one thinks of a small gasoline engine, one tends to think of it as a self-contained little powerpak; perhaps it would be
