Challenges in Validating a Thermo-Hydrodynamic Gas Foil Bearing Model
Abstract Gas foil bearings (GFBs) are suitable for high speed and temperature applications where conventional lubricated bearing solution are not feasible. This requires the pre-diction of bearing temperatures and thus a thermal model considering the heat genera-tion and heat flow paths in the bearing. The effects of two different bump foil stiffness (Iordanoff and Le Lez [1,2]) and heat transfer models (a simplified and a detailed one) are presented in respect to measured temperatures from literature [3,4]. The compari-son is drawn over a wide range of operational conditions as well as measuring posi-tions, which in such detail has not been shown before. While good agreement is found for some of the conditions and positions, only reasonable agreement is found for others. The deviations and difficulties in validating a thermal model against experiments are highlighted in a discussion about various temperature influencing parameters, especial-ly concerning the change of clearance during operation. In conclusion it is found, that the models are able to predict temperatures reasonably well, but require delicate fine-tuning to achieve these results. Finally, the impact of the temperature on the maximum load capacity at a range of speeds is shown in a comparison between an isothermal calculation and one with temperature consideration.