This paper presents an experimental investigation of the dynamic force performance of gas foil bearings (GFBs) at high temperatures. A dynamic performance test rig with a GFB mounted on a rotating hollow shaft, heated by a cartridge heater inside the hollow shaft, and excited by two orthogonally positioned electromagnetic shakers determines the frequency dependent stiffness and damping coefficients of the test GFB for increasing shaft temperatures. The test heater temperatures are 21°C (room temperature without heating), 100°C, 200°C, 300°C, and 400°C, and the excitation frequencies are 120 Hz, 140 Hz, 160 Hz, and 180 Hz. The test rotating speed and static load are 12 krpm and 30 N, respectively. The vibration amplitude of the test GFB is adjusted to approximately 30 μm by controlling the power amplifier connected to the electromagnetic shakers throughout the series of experiments. The test results show that both the direct stiffness and damping coefficients of the test GFB increase with increasing excitation frequencies. As the shaft temperature increases, the direct stiffness coefficients decrease by ∼ 8%, and the direct damping coefficients decrease by approximately 30%. A model prediction benchmarked against the test data reveals that the cross-coupled stiffness coefficients are smaller than the direct stiffness coefficients for the test GFB.
Bibliographical noteFunding Information:
This material is based on works supported by the Korea Institute of Science and Technology (KIST) Research Project: R&D on Power Generation and Energy Storage Technology for Tri-Gen System and the Korea Ministry of Trade, Industry and Energy (MOTIE) Research Project: Commercialization of 200kW MGT for a Co-Generation System. The authors also acknowledge the support by the Human Resources Development program (No. 20114010100070) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the MOTIE.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering