Soft EHL Simulations of Lubricant Film Thickness in Textured Hard-on-Soft Bearings Considering Different Cavitation Models, in the Context of Prosthetic Hip Implants

We use soft elasto-hydrodynamic lubrication simulations to calculate the lubricant film thickness in textured hard-on-soft parallel slider bearings and compare a mass-conserving cavitation model based on the Elrod implementation of the Jakobsson, Floberg, and Olsson (JFO) theory to simplified Reynolds and half-Sommerfeld cavitation models. We determine the optimum texture design parameters that maximize the lubricant film thickness for a range of bearing operating conditions and compare the results obtained with the different cavitation models. We determine that the JFO cavitation model predicts smaller optimum texture aspect ratios than the Reynolds cavitation model, and that the difference between the lubricant film thickness calculated with the different cavitation models increases with increasing texture aspect ratio and decreasing flow factor. These results are useful to determine when the mass-conserving JFO cavitation model or the simplified Reynolds cavitation model should be employed. Furthermore, the results are relevant to designing textured hard-on-soft bearings with application in, e.g., prosthetic hip implants. Graphic Abstract