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Research Papers

An Efficient Iterative Coupled Model for the Study of the Insurgence of the Morton Effect in Tilting Pad Journal Bearings

[+] Author and Article Information
Duccio Griffini

Department of Industrial Engineering (DIEF),
University of Florence,
via di S. Marta 3,
Florence 50139, Italy
e-mail: duccio.griffini@unifi.it

Simone Salvadori

Department of Industrial Engineering (DIEF),
University of Florence,
via di S. Marta 3,
Florence 50139, Italy
e-mail: simone.salvadori@unifi.it

Enrico Meli

Department of Industrial Engineering (DIEF),
University of Florence,
via di S. Marta 3,
Florence 50139, Italy
e-mail: enrico.meli@unifi.it

Simone Panconi

Department of Industrial Engineering (DIEF),
University of Florence,
via di S. Marta 3,
Florence 50139, Italy
e-mail: simone.panconi@unifi.it

Alessandro Ridolfi

Department of Industrial Engineering (DIEF),
University of Florence,
via di S. Marta 3,
Florence 50139, Italy
e-mail: alessandro.ridolfi@unifi.it

Andrea Rindi

Department of Industrial Engineering (DIEF),
University of Florence,
via di S. Marta 3,
Florence 50139, Italy
e-mail: andrea.rindi@unifi.it

Francesco Martelli

Department of Industrial Engineering (DIEF),
University of Florence,
via di S. Marta 3,
Florence 50139, Italy
e-mail: francesco.martelli@unifi.it

Daniele Panara

Baker Hughes, a GE Company,
Piazza Enrico Mattei, Firenze FI 50127, Italy
e-mail: daniele.panara@bhge.com

Leonardo Baldassarre

Baker Hughes, a GE Company,
Piazza Enrico Mattei, Firenze FI 50127, Italy
e-mail: leonardo.baldassarre@bhge.com

1Corresponding author.

Manuscript received July 12, 2017; final manuscript received July 16, 2018; published online December 19, 2018. Assoc. Editor: Alexandrina Untaroiu.

J. Eng. Gas Turbines Power 141(5), 051013 (Dec 19, 2018) (13 pages) Paper No: GTP-17-1349; doi: 10.1115/1.4041107 History: Received July 12, 2017; Revised July 16, 2018

The introduction of the tilting pad journal bearing (TPJB) technology has allowed the achievement of important goals regarding turbomachinery efficiency in terms of high peripheral speed, enhanced power density, higher efficiency, and tolerated loads. That kind of technology overcomes the typical dynamic instability problem that affects fixed geometry bearings but, under certain working conditions, can be subjected to thermal instability phenomena, which are particularly significant at high peripheral speeds. In this work, the authors propose an innovative iterative procedure to forecast the thermal instability onset by using two coupled models, a thermo-structural one and a fluid dynamic one. The first one calculates the vibrations and the deformations due both to the external forces and to the temperature distribution applied on the rotor. The fluid dynamic model calculates the temperature profile by using as inputs the characteristics of the rotor, of the bearing and of the orbits, obtained by the thermos-structural code. After a general description of the iterative procedure is given, details of each tool are provided. Code validation is presented by means of comparison with available experimental and numerical data. Finally, the results of the iterative procedure are shown to prove its potential in forecasting instability thresholds. The model has shown a good trade-off between accuracy and efficiency, which is very critical when dealing with the extended time windows characterizing thermal instabilities. This research activity is in cooperation with the industrial partner Baker Hughes, a GE company, which provided the experimental data obtained thorough a dedicated experimental campaign.

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References

De Jongh, F. M. , and Morton, P. G. , 1996, “ The Synchronous Instability of a Compressor Rotor Due to Bearing Journal Differential Heating,” ASME. J. Eng. Gas Turbines Power, 118(4), pp. 816–824. [CrossRef]
Tong, X. , Palazzolo, A. , and Suh, J. , 2017, “ A Review of the Rotordynamic Thermally Induced Synchronous Instability (Morton) Effect,” ASME. Appl. Mech. Rev., 69(6), p. 060801. [CrossRef]
Tong, X. , and Palazzolo, A. , 2017, “ Measurement and Prediction of the Journal Circumferential Temperature Distribution for the Rotordynamic Morton Effect,” ASME. J. Tribol., 140(3), p. 031702. [CrossRef]
Gomiciaga, R. , and Keogh, P. S. , 1999, “ Orbit Induced Journal Temperature Variation in Hydrodynamic Bearings,” ASME J. Tribol., 121(1), pp. 77–84. [CrossRef]
Balbahadur, A. C. , and Kirk, R. G. , 2002, “ Part I—Theoretical Model for a Synchronous Thermal Instability Operating in Overhung Rotors,” Int. J. Rotating Mach., 10(6), pp. 469–475.
Balbahadur, A. C. , and Kirk, R. G. , 2002, “ Case Studies for a Synchronous Thermal Instability Operating in Overhung Rotors—Part II,” Int. J. Rotating Mach., 10(6), pp. 477–487.
Murphy, B. T. , and Lorenz, J. A. , 2009, “ Simplified Morton Effect Analysis for Synchronous Spiral Instability,”ASME Paper No. POWER2009-81030.
Lorenz, J. A. , and Murphy, B. T. , 2011, “ Case Study of Morton Effect Shaft Differential Heating in a Variable-Speed Rotating Electric Machine,” ASME Paper No. GT2011-45228.
Childs, D. W. , and Saha, R. , 2012, “ A New, Iterative, Synchronous-Response Algorithm for Analyzing the Morton Effect,” ASME. J. Eng. Gas Turbines Power, 134(7), p. 072501. [CrossRef]
Tong, X. , Palazzolo, A. , and Suh, J. , 2016, “ Rotordynamic Morton Effect Simulation With Transient, Thermal Shaft Bow,” ASME. J. Tribol., 138(3), p. 031705. [CrossRef]
Lee, J. G. , and Palazzolo, A. , 2012, “ Morton Effect Cyclic Vibration Amplitude Determination for Tilt Pad Bearing Supported Machinery,” ASME J. Tribol., 135(1), p. 011701. [CrossRef]
Grigorev, B. S. , Fedorov, A. E. , and Schmied, J. , 2015, “ New Mathematical Model for the Morton Effect Based on the THD Analysis,” Proceedings of the 9th IFToMM International Conference on Rotor Dynamics, Springer, Cham, Switzerland, pp. 2243–2253.
Panara, D. , Baldassare, L. , Griffini, D. , Mattana, A. , Panconi, S. , and Meli, E. , 2015, “ Numerical Prediction and Experimental Validation of Rotor Thermal Instability,” 44th Turbomachinery Symposium, College Station, TX, Sept. 14–16, pp. 1–18. http://oaktrust.library.tamu.edu/handle/1969.1/162126
Song, Y. , and Gu, C.-W. , 2015, “ Development and Validation of a Three-Dimensional Computational Fluid Dynamics Analysis for Journal Bearings Considering Cavitation and Conjugate Heat Transfer,” ASME J. Eng. Gas Turbines Power, 137(12), p. 122502. [CrossRef]
Griffini, D. , Insinna, M. , Salvadori, S. , Barucci, A. , Cosi, F. , Pelli, S. , and Righini, G. C. , 2017, “ On the CFD Analysis of a Stratified Taylor-Couette System Dedicated to the Fabrication of Nanosensors,” Fluids, 2(1), p. 8. [CrossRef]
Griffini, D. , Insinna, M. , Salvadori, S. , and Martelli, F. , 2015, “ Clocking Effects of Inlet Non-Uniformities in a Fully Cooled High-Pressure Vane: A Conjugate Heat Transfer Analysis,” ASME J. Turbomach., 138(2), p. 021006. [CrossRef]
Andreini, A. , Facchini, B. , Insinna, M. , Mazzei, L. , and Salvadori, S. , 2016, “ Hybrid RANS-LES Modeling of the Aerothermal Field in an Annular Hot Streak Generator for the Study of Combustor–Turbine Interaction,” ASME J. Eng. Gas Turbines Power, 139(2), p. 021508. [CrossRef]
Bontempo, R. , and Manna, M. , 2016, “ Analysis and Evaluation of the Momentum Theory Errors as Applied to Propellers,” AIAA J., 54(12), pp. 3840–3848. [CrossRef]
Bontempo, R. , and Manna, M. , 2017, “ Highly Accurate Error Estimate of the Momentum Theory as Applied to Wind Turbines,” Wind Energy, 20(8), pp. 1405–1419.
Montomoli, F. , Amirante, D. , Hills, N. , Shahpar, S. , and Massini, M. , 2014, “ Uncertainty Quantification, Rare Events, and Mission Optimization: Stochastic Variations of Metal Temperature During a Transient,” ASME J. Eng. Gas Turbines Power, 137(4), p. 042101. [CrossRef]
Griffini, D. , Salvadori, S. , and Martelli, F. , 2016, “ Thermo-Hydrodynamic Analysis of Plain and Tilting Pad Bearings,” Energy Procedia, 101, pp. 2–9.
Martelli, F. , and Manfrida, G. , 1978, “ Some Applications of Finite Element Technique in Journal Bearing Hydrodynamics,” Conference Proceedings on Numerical Methods in Laminar and Turbulent Flows, University College, Swansea, UK
Reddi, M. M. , 1969, “ Finite Element Solution of the Incompressible Lubrication Problem,” ASME J. Lubr. Technol., 91(3), pp. 524–533. [CrossRef]
Frene, J. , Nicholas, D. , Degueurce, B. , Berthe, D. , and Godet, M. , 1997, Hydrodynamic Lubrication—Bearings and Thrust Bearings, Vol. 33, Elsevier, Amsterdam, The Netherlands.
Constantinescu, V. N. , and Galetuse, S. , 1965, “ On the Determination of Friction Forces in Turbulent Lubrication,” ASLE Trans., 8(4), p. 367. [CrossRef]
Deng, D. , 2007, “ A Numerical and Experimental Investigation of Taylor Flow Instabilities in Narrow Gaps and Their Relationship to Turbulent Flow in Bearings,” Ph.D. thesis, University of Akron, Akron, OH. https://etd.ohiolink.edu/rws_etd/document/get/akron1185559974/inline
Hirs, G. G. , 1973, “ A Bulk-Flow Theory for Turbulence in Lubricant Films,” ASME. J. Lubr. Technol., 95(2), pp. 137–145. [CrossRef]
Lund, J. W. , 1964, “ Spring and Damping Coefficients for the Tilting-Pad Journal Bearing,” ASLE Trans., 7(4), pp. 342–352.
Someya, T. , Mitsui, J. , Esaki, J. , Saito, S. , Kanemitsu, Y. , Iwatsubo, T. , Tanaka, M. , Hisa, S. , Fujikawa, T. , and Kanki, H. , 1989, Journal-Bearing Databook, Someya, T., ed., Springer-Verlag, Berlin.
Balbahadur, A. C. , 2001, “ Thermoelastohydrodynamic Model for the Morton Effect Operating in Overhung Rotors Supported by Plain or Tilting Pad Journal Bearings,” Ph.D. thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA.
Schmied, J. S. , Pozivil, J. , and Walch, J. , 2008, “ Hot Spots in Turboexpander Bearings: Case History, Stability Analysis, Measurements and Operational Experience,” ASME Paper No. GT2008-51179.
API, 2002, “ Axial and Centrifugal Compressors and Expander-Compressors for Petroleum, Chemical and Gas Industry Services,” American Petroleum Institute, Washington, DC, Standard No. 617.

Figures

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Fig. 1

Schematic of the experimental apparatus

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Fig. 2

The general architecture of the iterative loop

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Fig. 6

Comparison between the results obtained from the numerical code TILTPAD and experimental data from the work of Someya [29]. Results, shown with respect to rotational speed variation, are proposed in terms of: (a) relative eccentricity, (b) Nondimensional direct spring coefficients (Kij*), and (c) nondimensional direct damping coefficients (Cij*).

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Fig. 7

Sensitivity to the number of points along the tangential direction of a pad (Nx) and along the orbits (Npso): (a) B term values, (b) differential phase between hot and high spot, (c) calculation time (normalized with respect to the time needed for a structural iteration)

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Fig. 8

Filtered (red) and unfiltered (blue) amplitude vibration recorded at the bearing midspan

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Fig. 5

Area selection for the thermal boundary condition and example of a thermal steady-state solution

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Fig. 4

Example of convergent and divergent loop

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Fig. 3

Rotor and bearing model

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Fig. 9

Response at the overhung unbalance, along the x direction, for the W1, W2 and W3 configurations

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Fig. 10

Filtered (red) and unfiltered (blue) experimental displacements along the vertical direction at NDE bearing for the W3 configuration

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Fig. 11

Filtered (red) and unfiltered (blue) experimental displacements along the vertical direction at NDE bearing for the W2 configuration

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Fig. 12

Filtered (red) and unfiltered (blue) experimental displacements along the vertical direction at NDE bearing for the W1 configuration

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Fig. 13

Displacement amplitude for the W3 configuration

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Fig. 14

Orbit for each iteration at 13,200 and 13,400 RPM for the W3 configuration

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Fig. 15

Displacement Amplitude for the W2 configuration

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Fig. 16

Orbits for each iteration at 11,200 and 11,400 RPM for the W2 configuration

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Fig. 17

Displacement Amplitude for the W1 configuration

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Fig. 18

Orbits for each iteration at several rotational velocities for the W1 configuration

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