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.

The article presents a one-dimensional isothermal flow model with analytical solution for partially textured surfaces, nominally parallel. The model allows a simple and elegant parametric analysis of slider performance characteristics (load-carrying capacity, friction force, and friction coefficient) in terms of texture dimensions. It is shown that the friction force and load-carrying capacity do not practically depend on the number of cells. Optimum values of design parameters (dimensionless dimple depth and dimensionless textured length), allowing for maximum load-carrying capacity and minimum friction coefficient, are presented in the dimensionless form. The same model is used to give a phenomenologically based solution for the ‘equivalent step bearing’ in terms of load-carrying capacity or friction coefficient. The results show that the concept of equivalent step bearing is questionable, as the equivalent height of the step bearing is not uniquely determined.

A thermo-hydrodynamic analysis is performed for a face-to-face double seal configuration. Temperature and viscosity variations both across and along the sealing gap are considered and realistic boundary conditions are considered. The energy equation is solved analytically and the radial temperature variation is presented by an implicit equation. This approach enables analytical parametric investigation and gives better understanding of the effects of various parameters on the seal’s thermal behavior.

The present paper proposes an advanced bidimensional model necessary to calculate the temperature field in a journal bearing submitted to both rapid and slow start-ups. The model takes into account realistic thermal boundary conditions at fluid film-solid interfaces. The thermoelastic deformations of both the journal and of the bush are also considered and a special attention is paid to the ruptured zone of the film. The Finite Element Method (with upwind techniques whenever necessary) is employed to solve the equations implied by the model. Finally, the theoretical predictions were validated by comparison with experimental data. [S0742-4787(00)02701-6]