Simulation on the effect of the combustion parameters on the piston dynamics and engine performance using the Wiebe function in a free piston engine

► A dual piston type free piston engine was separated into a single cylinder model to perform a precise parametric study. ► The spark timing, piston initial velocity and combustion duration were varied to analyze their effects on the performance. ► A relationship was found between the combustion phase at top dead center and the initial piston velocity condition. ► The spark timing should be tuned to satisfy specific mass fraction burned profile for best engine performance.