An Investigation of the Effects of Structural Parameters on Operation Characteristics of a Free Piston Linear Engine using Numerical Analysis

A numerical analysis was investigated on the two stroke free piston linear engine. The analyses were carried out based on the combination of three model including dynamic, linear alternator and thermodynamic model. The reciprocating mass, air gap length, spring hardness, and dimension of cylinder were used as investigation parameters in the paper. The simulation results showed that by changing the reciprocating mass from 1 kg to 2.5 kg, the motion characteristic and performance of engine are reduced. Contrary to effects of reciprocating mass, the performance of engine was increased by increasing air gap length from 1.5mm to 3mm. In other hand, when increasing spring hardness from 0.5 N/mm to 14.7 N/mm, the operation characteristic was improved. Beside, the changing for some parameters related to the dimension of cylinder also had certain effects to the operation of the engine.