Characteristics of lubrication at nano scale on the performance of transversely rough slider bearing

Abstract

Efforts have been made within film lubrication at nano scale of a slider bearing. Bacally, the combination of the properties of surfalubricant and viscosity of the lubricant are red molecule dominate the fluid field. The rough-ness of the surfaces is characterized by a random variable with non zero mean, variance and skewness. The associ-ated Reynolds’ equation is then stochastically averaged and solved with suitable boundary conditions to get the pressure distributions which in turn, lead to the calculation of load carrying capacity. It is observed that the effect of transverse roughness is adverse in general. However, this negative effect is relatively less when considered with thin film lubrication for lower and moderate values of film thickness at maximum film pressure. The negatively skewed roughness increases the load carrying capacity substantially, which gets further increased in the case of negative variance. It is established that load carrying ca-pacity increases due to the thin film lubrication at nano scale. The existence of couple stress enhances the load carrying capacity. Besides, the characteristic length con-tributing to the couple stress increases the load carrying capacity considerably while the friction decreases. Size dependent effects are observed in the lubrication with cou-ple stress and the thinner the lubrication film is the more obvious becomes the effect.