Identification of the dynamic performance of a gas foil journal bearing operating at high temperatures†

다국어 초록 (Multilingual Abstract)

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, andexcited by two orthogonally positioned electromagnetic shakers determines the frequency dependent stiffness and damping coefficientsof 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 loadare 12 krpm and 30 N, respectively. The vibration amplitude of the test GFB is adjusted to approximately 30 μm by controlling the poweramplifier connected to the electromagnetic shakers throughout the series of experiments. The test results show that both the direct stiffnessand damping coefficients of the test GFB increase with increasing excitation frequencies. As the shaft temperature increases, thedirect stiffness coefficients decrease by ~ 8%, and the direct damping coefficients decrease by approximately 30%. A model predictionbenchmarked against the test data reveals that the cross-coupled stiffness coefficients are smaller than the direct stiffness coefficients forthe test GFB.

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