Thermohydrodynamic analysis of bump-type gas foil bearings using bump thermal contact and inlet flow mixing models

Implementation of gas foil bearings (GFBs) in high-temperature applications requires a reliable thermal model that accounts for heat transfers within the rotor-GFB system. The proposed thermohydrodynamic (THD) model takes into account energy transports in air film, heat conductions of shaft, thermal resistance of bump layer, and heat conduction in GFB housing. The model also incorporates analytical models for bump thermal contact and inlet flow mixing to improve the prediction accuracy. Published experimental test data benchmark the THD model predictions. Finally, this paper proposes a new GFB cooling scheme, i.e., supplying a cooling flow radially into the inlet flow mixing zone.