In this work, we propose a robust modeling and analysis technique of the piston-lubrication system considering fluid–structure interaction. The proposed schemes are based on combining the elastohydrodynamic analysis and multi-flexible body dynamics. In particular, multi-flexible body dynamics analysis can offer highly precise numerical results regarding nonlinear deformation of the piston skirt and cylinder bore, which can lead to more accurate results of film thickness for gaps filled with lubricant and of relative velocity of facing surfaces between the piston skirt and the cylinder block. These dynamic analysis results are also used in the elastohydrodynamic analysis to compute the oil film pressure and asperity contact pressure that are used as external forces to evaluate the dynamic motions of the flexible bodies. A series of processes are repeated to accurately predict the lubrication characteristics such as the clearance and oil film pressure. In addition, the Craig–Bampton modal reduction, which is a standard type of component mode synthesis, is employed to accelerate the computational speed. The performance of the proposed modeling schemes implemented in the RecurDyn™ multi-flexible body dynamics environment is demonstrated using a well-established numerical example, and the proposed simulation methods are also verified with the experimental results in a motor cycle engine (gasoline) which has a four cycle, single cylinder, overhead camshaft (OHC), air cooled.

An analysis for operating characteristics of piston lubrication system is performed based on the numerical model in the area of fluid-structure interaction. A numerical model with an integration of elastohydrodynamics and multi-flexible-body dynamics (MFBD) is developed to analyze lubrication characteristics such as oil film thickness and pressure. In particular, elastic deformation of components in piston lubrication system through modal reduction method is reflected on elastohydrodynamic analysis. The oil film pressure evaluated from elastohydrodynamic analysis is used as external force to calculate the elastic deformation of flexible bodies in multi-flexible-body dynamics (MFBD) again. A series of process proposed in this study is available for the analysis of realistic elastohydrodynamic lubrication phenomenon. Moreover, asperity contact effect is also implemented. Finally, a numerical example for the piston lubrication system is also demonstrated.