Research on Effect of Oil Film Inertia on Piston Skirt by Iteration Method

The influence of oil film inertia on piston skirt lubrication in a high speed engine is investigated by an iteration method that alternately solves the Navier-Stocks equations and the Reynolds equation by finite element method and difference method. The Reynolds lubrication equation including oil film inertia is developed, in which the inertia coefficient is introduced to investigate the effect of oil film inertia. The iteration procedure and finite formulation of solving the new Reynolds lubrication equation are given to analyze the effect of oil film on piston skirt in this kind of engine. The calculation results show that the oil film inertia has some effects on the friction force, pressure force and load capacity of oil film and its effect is obvious for the last. The Reynolds lubrication equation proposed can be also used to analyze the lubrication performance of the piston skirt in low or medium speed engine and some other lubrication problems generally excluding oil film inertia with the inertia coefficient being set at zero.