Simulation of a Two-Stroke Spark Ignition Free Piston Linear Engine Motion

Abstract. Two-stroke spark ignition free piston linear engine concept is analyzed in this paper. The main components of the engine are combustion chamber, scavenging chamber, kickback chamber and slider-piston. Dynamic and thermodynamic models of the slider-piston motion are presented. Also, the effect of various heat additions and compression ratio on the slider-piston velocity, time taken for one stroke, and stroke length are explored. By using selected engine variables, the motion of the two-stroke free piston linear engine is successfully simulated. The results show that the velocity profile of slider-piston motion is non-sinusoidal. By varying the amount of heat addition, the velocity and stroke length of slider-piston will increase accordingly. However, by increasing compression ratio, the velocity of slider piston is noted to increase but the stroke length of slider-piston remains constant.