The free piston engine is an engine which gives a freedom motion for mechanical linkage in variable stroke according to load. Number of advantages is available in free piston engine like Simple design with few moving parts, giving a compact engine with low maintenance costs and reduced frictional losses. It is having a Multi fuel capability and more Flexibility and reliability. It is very easy starting and control limitations. Free piston engines are widely used as submarine air compressor units and these engines are suitable for power generation in medium power range.
The free-piston engine is further well suited for Homogenous Charge Compression Ignition operation. The main aim of free-piston engine is engine control, which can only be said to be fully solved for single piston hydraulic free-piston engines. In free piston engines, the stroke of the piston is used directly to produce hydraulic, pneumatic or electric energy. The designs of free piston engines can be divided into three categories like single piston, dual piston and opposed piston.
