Effects of boundary slips on thermal elastohydrodynamic lubrication under pure rolling and opposite sliding contacts

In elastohydrodynamic lubrication (EHL) contact, the film thickness strongly depends on boundary slips, including velocity slip and thermal slip at the solid-lubricant interface. In the EHL studies published thus far, velocity slip at the solid-lubricant interface has been investigated individually without considering thermal slip. In this study, the effects of both types of boundary slip on film thickness were investigated simultaneously in rolling/sliding contact. Numerical simulations were conducted based on the modified Reynolds equation and energy equation by considering boundary slips on the sliding surface. The results indicate that the velocity slip causes a reduction in film thickness under pure rolling contact, while a shifted surface dimple is formed along the sliding direction due to both velocity slip and thermal slip under zero entrainment velocity (ZEV) contact.