Self-Adapting Microscale Surface Grooves for Hydrodynamic Lubrication

Abstract

The tribological performance of a lubricated surface depends largely on the ability of the surface to maintain a sufficient film thickness under high loads. One way of improving the performance is to modify the surface by inducing changes in the geometry of the surface. This work deals with modeling, creating, and testing novel adaptive microscale surface geometries to improve the tribological performance in terms of their load carrying capacity and stiffness. Numerical methods are used to model and simulate the performance of these surfaces. The coupled mechanisms of elastic deformation and hydrodynamic fluid pressure were solved simultaneously to give the load support. A parametric study was also performed by varying the input conditions and variables involved. Efforts were made to optimize the geometry of the surface to improve its load-carrying capacity and stiffness. Numerical results show that the adapting surfaces are able to increase the effective stiffness of the hydrodynamic film in comparison to conventional grooved surfaces. It was also theoretically shown that in some cases the adapting microscale structures perform better in terms of the load-carrying capacity for the same amount of film thickness.