Technical Brief

Structural Stiffness and Damping Coefficients of a Multileaf Foil Bearing With Bump Foils Underneath

[+] Author and Article Information
Ye Tian

e-mail: a.g.o.u2@stu.xjtu.edu.cn

Yanhua Sun

e-mail: sunyanhua@mail.xjtu.edu.cn

Lie Yu

e-mail: yulie@mail.xjtu.edu.cn
State Key Laboratory for Strength and Vibration
of Mechanical Structures,
Xi'an Jiaotong University,
Xi'an, Shaanxi Province 710049, China

Contributed by the Structures and Dynamics Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received July 28, 2013; final manuscript received November 13, 2013; published online December 12, 2013. Assoc. Editor: Jerzy T. Sawicki.

J. Eng. Gas Turbines Power 136(4), 044501 (Dec 12, 2013) (8 pages) Paper No: GTP-13-1276; doi: 10.1115/1.4026054 History: Received July 28, 2013; Revised November 13, 2013

This paper presents a multileaf foil bearing (MLFB), which consists of four resilient top foils and four stiff bump foils underneath; thus, a high supporting capacity and a high damping capacity can be achieved. A specially designed test rig is used to identify the structural stiffness and damping coefficients of the MLFB. The rotor of the test rig is supported by two journal MLFBs and a thrust active magnetic bearing (AMB) and the static and dynamic loads are applied by two radial AMBs. The tests on MLFBs were conducted under conditions of no shaft rotation at different angular positions and journal displacements with different excitation frequency. A frequency domain identification method is presented to determine the stiffness and damping coefficients. Static measurements show nonlinear deflections with applied forces, which varies with the orientation of the load angular position. The dynamic measurements show that the stiffness and equivalent viscous damping change with the excitation frequency. Furthermore, the stiffness and damping coefficients are related to the operating position where dynamic load tests were conducted. The investigation provides extensive measurements of the static and dynamic characteristics of the MLFB. These results can serve as a benchmark for the calibration of analytical tools under development.

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Heshmat, C. A. and Heshmat, H., 1995, “An Analysis of Gas-Lubricated, Multileaf Foil Journal Bearings With Backing Springs,” ASME J. Tribol., 117, pp. 437–443. [CrossRef]
DellaCorte, C., 2012, “Oil-Free Shaft Support System Rotordynamics: Past, Present and Future Challenges and Opportunities,” Mech. Syst. Signal Proc., 29, pp. 67–76. [CrossRef]
Heshmat, H., Walton, J. F.II, and Tomaszewski, M. J., 2005, “Demonstration of a Turbojet Engine Using an Air Foil Bearing,” ASME Paper No. GT2005-68404. [CrossRef]
Radil, K. C. and DellaCorte, C., 2009, “Foil Bearing Starting Considerations and Requirements for Rotorcraft Engine Applications,” 65th American Helicopter Society International Annual Forum, Grapevine, TX, May 27–29, Paper No. ARL-TR-4873.
Agrawal, G. L., 1997, “Foil Air/Gas Bearing Technology—An Overview,” ASME Paper No. 97-GT-347.
Heshmat, H., 1994, “Advancements in the Performance of Aerodynamic Foil Journal Bearings: High Speed and Load Capacity,” ASME J. Tribol., 116, pp. 287–295. [CrossRef]
Agrawal, G. L., 1998, “Foil Air Bearings Cleared to Land,” ASME Mech. Eng., 120(7), pp. 78–80.
Barnett, M. A. and Silver, A., 1970, “Application of Air Bearing to High-Speed Turbomachinery,” SAE Paper No. 700720. [CrossRef]
DellaCorte, C., Lukaszewicz, V., Valco, M. J., Radil, K. C., and Heshmat, H., 2000, “Performance and Durability of High Temperature Foil Air Bearings for Oil-Free Turbomachinery,” STLE Tribol. Trans., 43(4), pp. 774–780. [CrossRef]
Ku, C. P. and Heshmat, H., 1992, “Compliant Foil Bearing Structural Stiffness Analysis Part I: Theoretical Model—Including Strip and Variable Bump Foil Geometry,” ASME J. Tribol., 114, pp. 394–400. [CrossRef]
Ku, C. P. and Heshmat, H., 1994, “Structural Stiffness and Coulomb Damping in Compliant Foil Journal Bearing: Theoretical Considerations,” STLE Tribol. Trans., 37, pp. 525–533. [CrossRef]
DellaCorte, C., Radil, K. C., Bruckner, R. J., and Howard, S. A., 2008, “Design, Fabrication, and Performance of Open Source Generation I and II Compliant Hydrodynamic Gas Foil Bearings,” STLE Tribol. Trans., 51, pp. 254–264. [CrossRef]
DellaCorte, C. and Valco, M. J., 2000, “Load Capacity Estimation of Foil Air Journal Bearings for Oil-Free Turbomachinery Applications,” STLE Tribol. Trans., 43, pp. 795–801. [CrossRef]
DellaCorte, C., Zaldana, A., and Radil, K., 2004, “A System Approach to the Solid Lubrication of Foil Air Bearing for Oil-Free Turbomachinery,” ASME J. Tribol., 126, pp 200–207. [CrossRef]
Radil, K. C. and DellaCorte, C., 2002, “The Effect of Journal Roughness and Foil Coatings on the Performance of Heavily Loaded Foil Air Bearings,” STLE Tribol. Trans., 45(2), pp 199–204. [CrossRef]
Rubio, D. and San Andrés, L., 2005, “Structural Stiffness, Dry-Friction Coefficient and Equivalent Viscous Damping in a Bump-Type Foil Gas Bearing,” ASME Paper No. GT2005-68384. [CrossRef]
Kim, T. H. and San Andrés, L., 2009, “Effects of a Mechanical Preload on the Dynamic Force Response of Gas Foil Bearings: Measurements and Model Predictions,” STLE Tribol. Trans., 52, pp. 569–580. [CrossRef]
Zorzi, E. S., 1977, “Gas Lubricated Foil Bearing Development for Advanced Turbomachines,” AiResearch Manufacturing Company of Arizona, Phoenix, Technical Report No. AFAPL TR-76-114.
Arakere, N. K. and Nelson, H. D., 1992, “An Analysis of Gas-Lubricated Foil-Journal Bearings,” STLE Tribol. Trans., 35, pp. 1–10. [CrossRef]
Arakere, N. K., 1996, “Analysis of Foil Journal Bearings With Backing Springs,” STLE Tribol. Trans., 39, pp. 208–214. [CrossRef]
Agrawal, G. L., 1997, “Hydrodynamic Fluid Film Bearing,” U.S. Patent No. 5,634,723.
Saville, M. P. and Gu, A. L., 1992, “High Load Capacity Journal Foil Bearing,” U.S. Patent No. 5,116,143.
Lee, Y. B., Kim, C. H., Lee, N. S., and Kim, T. H., 2002, “Hybrid Air Foil Journal Bearing and Manufacturing Method Thereof,” U.S. Patent No. 2002/0097927 A1.
Ye, T., Yanhua, S., and Lie, Y., 2012, “Steady State Control of Hybrid Foil-Magnetic Bearings,” ASME Paper No. GT2012-68394. [CrossRef]
Kasarda, M. E., Marshall, J., and Prins, R., 2007, “Active Magnetic Bearing Based Force Measurement Using the Multi-Point Technique,” Mech. Res. Commun., 34(1), pp. 44–53. [CrossRef]
Kim, K. J. and Lee, C. W., 2003, “Identification of Dynamic Stiffness of Squeeze Film Damper Using Active Magnetic Bearing System as an Exciter,” The 2nd International Symposium on Stability Control of Rotating Machinery (ISCORMA-2), Gdansk, Poland, August 4–8.
Rubio, D. and San Andrés, L., 2006, “Bump-Type Foil Bearing Structural Stiffness: Experiments and Predictions,” ASME J. Eng. Gas Turbines Power, 128(3), pp. 653–660. [CrossRef]
Schweitzer, G. and Maslen, E. H., 2009, Magnetic Bearings: Theory, Design, and Application to Rotating Machinery, Springer-Verlag, Berlin/Heidelberg, pp. 167–174.
Zutavern, Z. S. and Childs, D. W., 2008, “Identification of Rotordynamic Forces in a Flexible Rotor System Using Magnetic Bearings,” ASME J. Eng. Gas Turbines Power, 130, p.022504. [CrossRef]
Coleman, H. and Steele, W., 2009, Experimentation, Validation and Uncertainty Analysis for Engineers, 3rd ed., John Wiley and Sons, New York, pp. 61–65.
Salehi, M., Heshmat, H., and Walton, J. F., 2007, “Advancements in the Structural Stiffness and Damping of a Large Compliant Foil Journal Bearing: An Experimental Study,” ASME J. Eng. Gas Turbines Power, 129, pp. 154–161. [CrossRef]
DellaCorte, C., 2011, “Stiffness and Damping Coefficient Estimation of Compliant Surface Gas Bearings for Oil-Free Turbomachinery,” STLE Tribol. Trans., 54(4), pp. 674–684. [CrossRef]


Grahic Jump Location
Fig. 1

Schematic example of journal foil bearings: (a) leaf-type foil bearing, and (b) bump-type foil bearing

Grahic Jump Location
Fig. 2

Schematic of the multileaf foil bearing (MLFB)

Grahic Jump Location
Fig. 3

Schematic of the test rig

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Fig. 4

Load and angular positions

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Fig. 5

Measured static load versus journal displacement. (a) AP0: load on middle of bump strip and (b) AP1: load on edge of bump strip.

Grahic Jump Location
Fig. 6

Static structural stiffness versus journal displacement

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Fig. 7

Test positions and excitation directions

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Fig. 8

Schematic of the dynamic model

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Fig. 10

Measured equivalent viscous damping: (a) cnnf, (b) cttf, (c) cntf, and (d) ctnf

Grahic Jump Location
Fig. 9

Measured structural stiffness: (a) knnf, (b) kttf, (c) kntf;, and (d) ktnf



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