A Concurrent Reynolds BC Algorithm for Piston Ring Cavitation Lubrication Problems with Surface Roughness

Piston ring dynamics play an important role in the lubricant characteristics of reciprocating engines that lead to engine wear and high consumption of lubricating oil. Due to the complexity of realistic test and working conditions, a study of cavitation with surface roughness and its effect on piston ring lubrication was conducted in a simulation program based on mass-conserving theory that is solved with the Newton-Raphson method. Lubrication models such as mixed lubrication, asperity contact, blow-by/blow-back flow, and cavitation were used in this study. The simulation algorithm consists of four processes: establishment of the three different lubrication models, dealing with the finite difference method, numerical stability treatment for the cavitation zone, and the addition of surface roughness and the shear factor to the model. Results calculated with this model were compared with two other models, and an analysis of the results indicates that the developed simulation program can illustrate problems of piston ring lubrication in accordance with the state of art of lubrication theory.