Experimental investigation on the groove effect in hydrodynamic lubrication

Abstract

In this article, a custom-built test apparatus was used to measure the film thickness in a conformal contact consisting of a stationary fixed-incline block and a moving transparent disc. Two groups of grooved block surfaces were used: one with a step at the inlet, and the other without the inlet step. Under parallel-gap conditions, effective load-carrying lubricant films can be found only when surfaces with an inlet step are used, and a partially grooved surface in the inlet region can generate film thickness larger than the fully grooved one. If the outlet land is larger than the inlet land, a thicker film as well as a higher load-bearing capacity will be obtained. In this study, groove shows a negative impact on the hydrodynamic lift. And not all diverging clearance can form the cavitation, as it depends on the geometry configurations. The classical Reynolds’ solutions should be carefully used in the analyses of groove effects. The results can be useful for experiments in the case in which no cavitation occurs.