Investigation on start-up performance of gas foil bearing considering wear topography evolution of non-Gaussian surface

To reveal the influence of topography evolution caused by abrasive wear of the top foil on the start-up performance of gas foil bearing (GFB), the transient gas mixed lubrication-wear model for non-Gaussian surface is developed by deriving the expression of wear particle size probability density function and establishing the relationship between wear particle size and surface height distribution. The effects of wear topography evolution and initial surface parameters on the start-up performance of GFB are studied. The results show that compared with the results ignoring wear topography evolution, the standard deviation, skewness and the minimum lift-off speed are smaller when the wear topography evolution is considered. The minimum lift-off speed and the wear volume diminish with the decrease of the initial standard deviation and skewness. This study can predict the wear topography evolution of top foil surface from start-up to lift-off.