–
The construction of this stirling engine is quite simple. The acrylic container holds the working air. The air pushes the piston. The piston rotates the fly wheel. The fly wheel in turn pushes the displacer (the Styrofoam piece). The piston and the displacer are connected to the fly wheel in such a way that they are always out of phase by a quarter cycle. This automatically synchronizes the displacer to fulfill the important function of pushing the air to the hot end when it’s the air’s turn to push, and pushing the air to the cold end when it’s the fly wheel’s turn to push.
–
–
–
–
The diagrams above show the positions of the piston and the displacer at four stages. During abc, the displacer moves the air towards the hot end so that the air is heated up. This is when we extract work done by the air. During cda, the displacer moves the air towards the cold end so that the air is cooled down. This is when work is done by the piston. Since abc occurred at higher temperature and pressure, in one complete cycle, net work done is by the air.