Study on Leakage Effect Factors of Two-Stroke Micro Free Piston Swing Engine

Area of Science:

• Thermodynamics
• Fluid Dynamics
• Mechanical Engineering

Background:

• Micro free piston swing engines (MFPSE) are portable power devices.
• Seal performance is critical for MFPSE dynamic properties and efficiency.

Purpose of the Study:

• To establish a leakage model for two-stroke micro free piston swing engines.
• To investigate the impact of seal parameters on microengine performance and leakage.

Main Methods:

• Utilized compressible flow Reynolds Navier-Stokes equations.
• Developed a nondimensional mass leakage model.
• Performed simulations to analyze seal gap height and size factor effects.

Main Results:

• Increased seal gap height reduced maximum pressure and cycle power.
• Mass leakage increased significantly with seal gaps > 10 μm or size factor < 0.4.
• Compression ratio < 5 had minimal impact on mass leakage.

Conclusions:

• Identified key factors influencing mass leakage in MFPSE.
• Provided insights for optimizing seal and structural design in two-stroke micro free piston swing engines.