- Volume 39 Issue 10
DOI QR Code
Identification of Frequency-Dependent Dynamic Characteristics of a Bump Structure for Gas-Foil Bearings via 1-DOF Shaker Tests Under Air Pressurization
가스 포일 베어링 범프 구조의 1 자유도 가진/가압 실험을 통한 주파수 의존 동특성 규명
- Sim, Kyuho (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Sci. & Tech.) ;
- Park, Jisu (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Sci. & Tech.) ;
- Lee, Sanghun (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Sci. & Tech.)
- Received : 2015.06.11
- Accepted : 2015.07.12
- Published : 2015.10.01
Recently, the importance of rotordynamic stability has been increased because of the tendency to employ ultra-high speeds in rotating machinery. In particular, the dynamic characteristics of gas bearings for high-speed rotating machinery need to be identified at various excitation frequencies to predict the rotor's behavior. In this study, we perform dynamic loading tests for gas-foil bearings (GFBs) to determine the bump foil structure and an air-film combined bump-foil structure for varying excitation frequencies. We calculate the dynamic characteristics from the measured force and displacement data. The air film is generated by a pressurized air supply. Based on the results, the stiffness coefficients of the bump structure and the air-film combined bump structure increased, while the damping coefficients decreased at increasing excitation frequencies. Further, the stiffness and damping coefficients of the air-film combined structure show lower values than those of the bump structure. Consequently, we identify the frequency-dependent dynamic characteristics of the bump structure and the effect of gas film on the dynamic characteristics of GFBs. Furthermore, to reveal the effectiveness of the proposed method, we perform experiments and discuss two methods of extracting the dynamic characteristics from the measured data.
Gas Foil Bearing;Dynamic Characteristics;Hysteresis loop
Supported by : 한국연구재단
- Lee, Y.-B., 2012, "Trends of Rotor Dynamics and Tribology Element," The KSFM Journal of Fluid Machinery, Vol. 14, No. 2, pp. 80-84.
- Heshmat, H., Shapro, W. and Gray, S., 1981, "Development of Foil Journal Bearings for High Load Capacity and High-Speed Whirl Stability," Journal of Lubrication Technology, Vol. 104, No. 2, pp.149-156.
- Jo, J.-H., Kim, C.-H. and Rhim, Y.-C., 2005, "A Study on the Dynamic Characteristics of Bump Foils Considering Coulomb Friction Damping in Air Foil Bearing," Journal of the KSTLE, 41th Conference and Annual General Meeting, pp.100-106.
- Lee, Y.-B., Kim, T.-H., Kim, C.-H., Lee, N.-S. and Dong-Hoon Choi, 2002, "An Experimental Study on the Structural Dynamic Coefficients of Self-Acting Compliant Foil Journal Bearings," Journal of the KSTLE, Vol. 18, No. 1, pp.42-48.
- Salehi, M., Heshmat, H. and Walton, J. F., 2003, "On the Frictional Damping Characterization of Compliant Bump Foils," Journal of Tribology, Vol.125, No.4, pp.804-813. https://doi.org/10.1115/1.1575774
- Andres, L. S. and Chirathadam, T. A., 2011, "Metal Mesh Foil Bearing: Effect of Motion Amplitude, Rotor Speed, Static Load, and Excitation Frequency on Force Coefficients," Journal of Engineering for Gas Turbines and Power, Vol. 133, No. 12, pp.122503(10 pages). https://doi.org/10.1115/1.4004112
- Zhang, D., Scarpa, F., Ma, Y., Hong, J. and Mahadik, Y., 2014, "Dynamic Mechanical Behavior of Nickel-Based Superalloy Metal Rubber," Journal of Materials & Design, Vol.56, April, pp.69-77. https://doi.org/10.1016/j.matdes.2013.10.088
- Carfagni, M., Lenzi E. and Pierini M., 1998, "The Loss Factor as a Measure of Mechanical Damping," Proceedings of the 16th International Modal Analysis Conference, Vol. 3243, pp.580(5 pages).
- Figliola, R. S. and Beasley, D. E., 2010, "Theory and Design for Mechanical Measurements," 4rd edition, John Wiley & Sons, Inc., New York, pp.133-155.
- Inman, D. J., 2012, "Engineering Vibrations," 3rd edition, Pearson Education Korea, inc.
- Richard S. Figliola, Donald E. Beasley, 2010, "Theory and Design for Mechanical Measurements," 4th, Seoul, pp.116-260.
- Performance Measurements of Gas Bearings With High Damping Structures of Polymer and Bump Foil Via Electric Motor Driving Tests and One Degree-of-Freedom Shaker Dynamic Loading Tests vol.139, pp.9, 2017, https://doi.org/10.1115/1.4036063