The initial concept for this type of Stirling engine was developed by Wilfried Schlagenhauf in Germany in 1991. Mr. Schlagenhauf, a school technology teacher, originally came up with the concept in order to better demonstrate the principles of Stirling engines to his students. A Stirling Engine is a heat engine that operates 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. It was originally utilized as an alternative for the steam engine, but was mostly used in low-power domestic items. It is, however, very quiet and efficient. Most Stirling engine designs incorporate a cylinder and power piston as well as a diplacer piston. Mr. Schlagenhauf searched for a way to eliminate the higher priced cylinder and piston arrangement. The balloon eliminated the need for the expensive, close tolerance power piston. Having the cylinder tilt away from the heat source rather than a displacer piston being pushed back and forth greatly simplified and lowered the cost of the apparatus. This kit allows you to build a close approximation of the design Mr. Schlagenhauf pioneered, and makes for an excellent classroom demonstration, science project, or family activity.
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