Axial gas foil bearings as lubricant-free bearings for high-speed rotors - Experimental investigations and numerical prediction

• Applicant: Professor Dr.-Ing. Robert Liebich
• Subject Area: Engineering Design, Machine Elements, Product Development ; Mechanics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 470968696

As part of the research project, experimental investigations of the dynamic behavior of Gas Foil Thrust Bearings (GFTBs) are carried out in order to create a systematically structured experimental database on GFTBs. This database is used for further scientific investigations, especially in numerical simulation for the development of new bearing types and the design of rotor systems supported by gas foil bearings, e.g. oil-free turbo compressors in fuel cell systems. For this purpose, the static and dynamic behavior of the elastic structure of the GFTB with different ramp and structure geometries is determined on the existing structural analysis test rig of the applicant. Furthermore, the stiffness and damping properties as well as the load carrying capacity of the GFTB are identified depending on various operating parameters on a parameter identification test bench to be set up. In addition, these experimentally determined bearing parameters are compared and validated with the numerical results of the simulation models already published by the applicant in various journal articles. Furthermore, based on the experience with the existing rotor dynamic test stand with Gas Foil Journal Bearings (GFJBs), a rotor dynamic GFTB test stand will be put into operation in order to analyze the influence of GFTBs and their modifications on the non-linear vibration behavior and the stability of rotor systems supported by axial and radial gas foil bearings. Thereby, the Onset Speed of Instability (OSI) and Onset Speed of Sub synchronous Vibration (OSSV) can be determined experimentally and compared with the numerical calculations.

• DFG Programme: Research Grants