This is traditionally known as an external combustion engine in contrast to an internal combustion engine where the heat input is by combustion of a fuel within the body of the working fluid. Unlike the steam engine's use of water in both its liquid and gaseous phases as the fluid, the Stirling engine encloses a fixed quantity of permanently gaseous fluid such as air or helium.
As in all heat engines, the general cycle consists of compressing cool gas, heating the gas, expanding the hot gas, and finally cooling the gas before repeating the cycle. On the heating tube, this does not means a used item, if you have concern on this issue, please skip off this item, thank you for understanding! That may incur in your country, when incur, it would be at your own responsibility to take care of.A complete kit, ready to run, it comes with. Perfectly suit for physics education demonstration purpose. Materials : Brass (engine) + Stainless Steel (flywheel + boiler bracket) + glass (boiler). This item is in the category "Toys & Hobbies\Models & Kits\Tools, Supplies & Engines\Paints". The seller is "coptel_technology" and is located in this country: CN. This item can be shipped worldwide.