Analytic and numerical study of lubrication dynamics for internal combustion engine piston assemblies and journal bearings

A modeling approach and solution schemes for piston-assembly dynamics with dynamic modeling, lubrication analysis and numerical analysis are developed. A theoretical and numerical study is included on stiff ODE features of lubrication dynamics for pistons and journal bearings. The numerical instabilities of implicit integration schemes are analyzed. Lubrication dynamics models are developed for one-piece and two-piece piston assemblies as well as cylindrical and non-cylindrical piston skirts, including an advanced lubrication cavitation model for piston skirts. The models are used to analyze the lubrication and dynamic characteristics of various piston assemblies.