Cavitation in Engine Lubricants: Visualisation Experiments in both a Single Ring Test Rig and a Single Cylinder Motored Diesel Engine to Complement on the Theoretical Modeling of Cavitation

The importance of studying cavitation lies in the fact that it can cause tremendous damage to fluid handling machinery. Cavitation generation is largely dependent on pressure fluctuation in the turbulent flow period as well as on the presence of air bubble nuclei.

The shape and dynamic behavior of oil film in a piston-ring pack after oil film rupture are greatly influenced by revolution speed. After dead center, negative pressure involving tension arises before oil film rupture occurs. With the generation of internal cavities tension is released but negative pressure is still maintained in those cavities.

This study is focused on the presentation of cavitation imaging. Images are both taken from a simplified single-ring test rig which is purpose built so that numerous uncertainties regarding the complex tribological phenomena between the piston-ring and cylinder wall to be omitted and a single cylinder diesel engine which was modified to accommodate quartz window sections, to take images of the piston-rings and liner interface. The experimental data give an insight of the rheological phenomena occurring and try to complement the lack of experimental data on this subject. Eventually, experimental results will be used on how best to model the cavitation at the interface of the piston-ring and the cylinder wall.