Hydrogen Utilization in Free Piston Engines: A Performance Investigation

This paper presents a dynamic analysis of a free-piston engine (FPE) using hydrogen gas as the working fluid for the first time. Initially, the governing dynamic equations of the FPE are derived. The performance of the B10-B engine is then evaluated based on the location of the closed-loop poles using five different working fluids: air, argon, nitrogen, helium, and hydrogen. The results indicate that hydrogen gas significantly enhances the engine’s operating frequency, output power, and startup conditions compared to other gases. Additionally, this study examines the impact of varying key parameters of the FPE, such as power and displacer mass, the cross-sectional area of the pistons and the rod connected to the displacer piston, and the displacer piston stiffness on the engine’s dynamics using the phase plane method. The findings reveal that the most optimal engine dynamics occur when hydrogen gas is used as the working fluid. Ultimately, the use of hydrogen as the working fluid leads to improved dynamic instability and increased output power, making it the optimal choice for FPEs, provided safety conditions are met to prevent combustion in the chamber.

Hydrogen Utilization in Free Piston Engines: A Performance Investigation Keywords:

free piston engine , Hydrogen , dynamic analysis