These are IC engines similar to the ones used in automotive applications. The piston engine needs to be mated with the propellor for creating the thrust required to move the aircraft through air. As seen from the images earlier, there are essentially two kinds based on the organization of the cylinders. An inline arrangement keeps the cylinders along a line ( or a v configuration.) and a radial configuration. with the cylinders distributed around the perimeter of a circle. They are also called reciprocating engines
The analysis for the piston engine is obtained from thermodynamic analysis of an ideal behavior on the pv diagram. For a typical four stroke engine