Optimizing surface texture for hydrodynamic lubricated contacts using a mass-conserving numerical approach

Surface texturing has been shown to reduce friction and increase the film thickness in various tribological applications (hydrodynamic bearings, mechanical seals, and cylinder-liner contacts). However, only few studies discuss optimal texturing properties, and most of them focus on the optimal dimple shape. This article proposes an in-depth study on the influence of cavitation and of different texturing parameters, especially the dimple depth, the texture extent, and the dimple aspect, on the hydrodynamic performance of textured contacts. The results are derived numerically, for contacts between plane surfaces that are parallel or inclined with respect to each other. The performance gains (film thickness and friction force) obtained by texturing are evaluated with respect to the performance of smooth contacts. Most notable findings are the optimal extent of the textured region (partial texturing and trapezoidal shape) and the optimal dimple aspect (longitudinal). Cavitation is shown to have a significant influence on the performance of near-parallel textured contacts, although it does not appear to contribute to the generated hydrodynamic lift. It is equally shown that the dimple arrangement with respect to the leading edge is a determining factor for the performance of near-parallel textured sliders.