Numerical Investigation of the EHL Performance and Friction Heat Transfer in Piston and Cylinder Liner System

A three-dimensional EHL analysis has been presented to investigate tribological performance of piston ring and cylinder liner contact. The average Reynolds equation and asperity contact approach are applied. For a more realistic simulation, the factors that have effects on the tribological performance of piston ring are considered as many as possible. The equation has been solved cyclically in a fully flooded inlet boundary condition and a flow-continuity Reynolds boundary condition for cavitation outlet zone. The results show that the elastic deformation and cylinder liner shape significantly affect the tribological performance of piston ring.

A heat transfer model has been built to evaluate the effect of friction heat on the temperatures of piston ring pack and cylinder liner. The temperature fields can be acquired by the FEM. The results show that the friction heat mainly affects the temperature of region near the top ring groove. The effects decrease on the region away from the top ring groove, especially on the piston skirt. The effect of friction heat on the temperature of cylinder liner is smaller than that of piston ring pack.