Tribo-dynamic modeling method and application to three-dimensional flexible PRL system.

• The real-time coupled tribo-dynamics calculation of piston-cylinder liner and piston ring-cylinder liner is realized. • Modeling is based on unified global coordinates, making the coupling and solution between lubrication and dynamics more efficient. • The influencing mechanism of piston deformation on the ring tribo-dynamics properties is given. • The effect of the assembly position on the ring tribo-dynamics properties is revealed, and the worst assembly position is discovered. Research on the tribo-dynamics of the piston-cylinder liner (PCL) and piston ring-cylinder liner (PRCL) is vital due to their role in generating over 50 % of total engine friction loss and the impact on carbon emissions. Traditional studies, hindered by the structural and functional differences between pistons and rings, required separate simulation models, often overlooking crucial coupling characteristics. A unified tribo-dynamics modeling method for the piston-ring-liner (PRL) system is proposed in this paper, integrating the ring pack and piston into one multi-body system. This article models with global coordinates, unifying the form of governing, film thickness, and load equations of discontinuous lubrication domains for more efficient dynamics-lubrication coupling. The described method is applied to a marine engine, and the new tribology characteristics discovered after calculations are exhibited. It shows how piston deformation impacts ring tribology, indicating that increased profile height reduces the squeezing effect by allowing more ring movement. Additionally, ring assembly position significantly affects tribology parameters' circumferential distribution. Installing the ring with the end gap facing the piston pin side should be avoided, as it maximizes the negative impact of elastic force and secondary motion, deteriorating lubrication. [Display omitted] [ABSTRACT FROM AUTHOR]