Tribological sensitivity training for EHD calculations

The influence of surface texture and roughness on shear and compressive forces in tribological applications is analyzed using numerical simulations and taking into account the real geometry of surface elements. Topographic data of representative surface structures are produced with high spatial resolution with an optical interference method. The three-dimensional velocity field in the lubricating film is using the Lattice Boltzmann method calculated for laminar flows of Newtonian fluids. For this velocity field are determined by comparison with the Reynolds differential equation, the pressure and shear flow factors. This approach allows an efficient determination of the hydrodynamic parameters of microstructured surfaces. Especially the influence of production-related anisotropies of surface textures on the hydrodynamic load capacity and friction is detected. The results show that detailed numerical simulations are suited to efficiently and accurately the tribological characteristics of lubricating films calculated, thus making a contribution can better understand and predict EHD problems.

Detail of the isosurfaces of the velocity component in the flow direction of the flow pressure at the crank element with anisotropic surface roughness. Left: axial flow, right angles to anisotropic structures.