Vibration transmission in lubricated piston-liner systems: Experimental and multi-physics coupled analysis

To accurately simulate the high-frequency vibrations induced by piston slap in engines, a 3D multi-physics coupled model under a multibody dynamic framework has been developed, incorporating multi-physics interactions like mixed lubrication and heat transfer. This novel model is specifically designed to investigate the transmission characteristics of vibrations across solid-liquid-solid interfaces, which is the core focus of this study. The results, for the first time, demonstrate that vibration signals exhibit distinct phases when transmitted through a liquid medium, as revealed by model simulations and experimental analysis. Additionally, two primary pathways are identified for the transfer of vibrations to the engine surface, with broadband vibration energy predominantly concentrated in the 2,500-5,000 Hz frequency range.