Perhaps it is the German blood in me that makes me fascinated with mechanical things. This explains my career choice as an automotive diesel technician and as a child I was always deconstructing toys and reassembling them, sometimes to repair but I always seemed to find myself intently involved. I would tune out whatever was going on around me. As adults we call that a hobby. Finding myself attracted to model Stirling Engines is no surprise because they are manageable, mechanical, scientific and for the most part very interesting to look at and watch them operate. I have a very basic model that I received from a friend but now I am looking for another, one that puts the energy to work in some way and if I can find it, one that requires assembly.
This is my engine running on 91% Isopropyl Alcohol and a low flame. The dry pellet fuel or denatured alcohol will burn hotter and the engine would run faster using those fuels. Isopropyl alcohol is generally not recommended due to it’s water content.
What is the Stirling engine?
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.The engine is like a steam engine in that all of the
engine’s heat flows in and out through the engine wall.
How it works.
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 working 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.
Above is an example of an inexpensive model sold on the internet. In addition to the pleasingly shiny aesthetics it harnesses the power of the engine to drive a micro generator that lights up an LED.
