Hybrid simulation of a free piston engine

Abstract

The free piston engine principle is one which has intrigued mechanical engineers for decades. Indeed, the original gas engine of Otto and Langden employed a piston assembly which did not contain the now conventional connecting rod and camshaft arrangement and hence may be considered as an early implementation of the free piston principle. Today, however, the free piston principle is normally applied to a highly supercharged two-stroke compression ignition engine in which two opposed reciprocating pistons are used in a diesel cylinder. These pistons do not transmit mechanical energy but instead pneumatic energy is delivered in the form of high-pressure, high-temperature exhaust gas to a separate power turbine to obtain shaft power.