Study on Stiffness Model of Bump Foil in Bump Foil Gas Bearings Based on Ansys Simulation Considering Axial Variable Loads

To address the inaccuracy of existing models in describing the stiffness distribution along the axial direction of bump foils, this study first establishes a simulation model applicable to bump foils based on Ansys Workbench. Specifically, by applying axial variable load at a node that matches the distribution of actual operating conditions, the deformation and stiffness characteristics of the bump foil are investigated. The research results show that, compared with the classic Heshmat model, the bump foil stiffness is not uniformly distributed in the axial direction; instead, it exhibits a trend of being higher in the middle and lower at both ends. Notably, when the nominal stiffness values are similar, the axial end displacement obtained from the Ansys simulation differs significantly from the result calculated by the Heshmat model, with the deviation reaching up to 17.7% of the peak displacement from the latter. Furthermore, this study also systematically analyzes the influence of the laws of the bump foil’s curvature radius, length, and friction coefficient on its stiffness.