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Research Papers

An Efficient Iterative Approach for the Analysis of Thermal Instabilities in Rotating Machines

[+] Author and Article Information
A. Rindi

Professor
Department of Industrial Engineering,
University of Florence,
Florence 50139, Italy
e-mail: andrea.rindi@unifi.it

L. Baldassarre

General Electric Oil & Gas,
Florence 50127, Italy
e-mail: Leonardo.Baldassare@ge.com

D. Panara

General Electric Oil & Gas,
Florence 50127, Italy
e-mail: daniele.panara@ge.com

E. Meli

Department of Industrial Engineering,
University of Florence,
Florence 50139, Italy
e-mail: enrico.meli@unifi.it

A. Ridolfi

Department of Industrial Engineering,
University of Florence,
Florence 50139, Italy
e-mail: alessandro.ridolfi@unifi.it

A. Frilli

Department of Industrial Engineering,
University of Florence,
Florence 50139, Italy
e-mail: amedeo.frilli@unifi.it

D. Nocciolini

Department of Industrial Engineering,
University of Florence,
Florence 50139, Italy
e-mail: daniele.nocciolini@unifi.it

S. Panconi

Department of Industrial Engineering,
University of Florence,
Florence 50139, Italy
e-mail: simone.panconi@unifi.it

Contributed by the Technical Committee on Vibration and Sound of ASME for publication in the JOURNAL OF VIBRATION AND ACOUSTICS. Manuscript received November 2, 2016; final manuscript received June 8, 2017; published online August 17, 2017. Assoc. Editor: Patrick S. Keogh.

J. Vib. Acoust 139(6), 061019 (Aug 17, 2017) (15 pages) Paper No: VIB-16-1526; doi: 10.1115/1.4037143 History: Received November 02, 2016; Revised June 08, 2017

Most of the technological developments achieved in the turbomachinery field during the last years have been obtained through the introduction of fluid dynamic bearings, in particular tilting pad journal bearings (TPJBs). However, even those bearings can be affected by thermal instability phenomena as the Morton effect at high peripheral speeds. In this work, the authors propose a new iterative finite element method (FEM) approach for the analysis of those thermal–structural phenomena: the proposed model, based on the coupling between the rotor dynamic and the thermal behavior of the system, is able to accurately reproduce the onset of thermal instabilities. The authors developed two versions of the model, one in the frequency domain and the other in the time domain; both models are able to assure a good tradeoff between numerical efficiency and accuracy. The computational efficiency is critical when dealing with the typical long times of thermal instability. The research activity has been carried out in cooperation with General Electric Nuovo Pignone SPA, which provided both the technical and experimental data needed for the model development and validation.

Copyright © 2017 by ASME
Topics: Bearings , Rotors
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References

Waukesha Bearings, 2016, “Tilting Pad Journal Bearing,” Waukesha Bearings, Pewaukee, WI, accessed June 30, 2017, http://www.waukbearing.com/en/engineered-fluid-film/product-lines/journal-bearings/tilt-pad-journal-bearings/
Nicholas, J. C. , 1994, “Tilting Pad Bearing Design,” 23rd Turbomachinery Symposium, Dallas, TX, Sept. 13–15, pp. 179–194. http://turbolab.tamu.edu/proc/turboproc/T23/T23179-194.pdf
Monmousseau, P. , Fillon, M. , and Frene, J. , 1998, “Transient Thermoelastohydrodynamic Study of Tilting-Pad Journal Bearings Under Dynamic Loading,” ASME J. Eng. Gas Turbines Power, 120(2), pp. 405–409. [CrossRef]
Monmousseau, P. , and Fillon, M. , 1999, “Frequency Effects on the TEHD Behavior of a Tilting-Pad Journal Bearing Under Dynamic Loading,” ASME J. Tribol., 121(2), pp. 321–326. [CrossRef]
Monmousseau, P. , Fillon, M. , and Frene, J. , 1998, “Transient Thermoelastohydrodynamic Study of Tilting-Pad Journal Bearings—Application to Bearing Seizure,” ASME J. Tribol., 120(2), pp. 319–324. [CrossRef]
Abu-Mahfouz, I. , and Adams, M. L. , 2005, “Numerical Study of Some Nonlinear Dynamics of a Rotor Supported on a Three-Pad Tilting Pad Journal Bearing,” ASME J. Vib. Acoust., 127(3), pp. 262–272. [CrossRef]
Dimarogonas, A. D. , 1973, “Newkirk Effect: Thermally Induced Dynamic Instability of High-Speed Rotors,” ASME Paper No. 73-GT-26.
Kellenberger, W. , 1980, “Spiral Vibrations Due to Seal Rings in Turbogenerators. Thermally Induced Interaction Between Rotor and Stator,” ASME J. Mech. Des., 102(1), pp. 177–184. [CrossRef]
Newkirk, B. L. , 1926, “Shaft Rubbing,” Mech. Eng., 48, pp. 830–832.
De Jongh, F. M. , and Morton, P. G. , 1994, “The Synchronous Instability of a Compressor Rotor Due to Bearing Journal Differential Heating,” ASME Paper No. 94-GT-035.
Guo, Z. , and Kirk, G. , 2011, “Morton Effect Induced Synchronous Instability in Mid-Span Rotor-Bearing Systems—Part 2: Models and Simulations,” ASME J. Vib. Acoust., 133(6), p. 061006. [CrossRef]
Guo, Z. , and Kirk, G. , 2011, “Morton Effect Induced Synchronous Instability in Mid-Span Rotor-Bearing Systems—Part I: Mechanism Study,” ASME J. Vib. Acoust., 133(6), p. 061004. [CrossRef]
Murphy, B. T. , and Lorenz, J. A. , 2010, “Simplified Morton Effect Analysis for Synchronous Spiral Instability,” ASME J. Vib. Acoust., 132(5), p. 051008. [CrossRef]
Keogh, P. S. , and Morton, P. G. , 1993, “Journal Bearing Differential Heating Evaluation With Influence on the Rotor Dynamic Behavior,” Proc. R. Soc. London, 441(1913), pp. 527–548. [CrossRef]
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]
Gomiciaga, R. , and Keogh, P. S. , 1999, “Orbit Induced Journal Temperature Variation in Hydrodynamic Bearings,” ASME J. Tribol., 121(1), pp. 77–84. [CrossRef]
Grigorev, B. S. , Fedorov, A. E. , and Schmied, J. , 2015, “New Mathematical Model for the Morton Effect Based on the THD Analysis,” IFToMM International Conference on Rotor Dynamics 2014 Congress, Springer, Cham, Switzerland, pp. 2243–2253. [CrossRef]
Kim, J. , Palazzolo, A. , and Gadangi, R. , 1995, “Dynamic Characteristics of TEHD Tilt Pad Journal Bearing Simulation Including Multiple Mode Pad Flexibility Model,” ASME J. Vib. Acoust., 117(1), pp. 123–135. [CrossRef]
Varela, A. C. , Fillon, M. , and Santos, I. F. , 2012, “On the Simplifications for the Thermal Modelling of Tilting-Pad Journal Bearings Under Thermoelastohydrodynamic Regime,” ASME Paper No. GT2012-68329.
Monmousseau, P. , Fillon, M. , and Frene, J. , 1997, “Transient Thermoelastohydrodynamic Study of Tilting-Pad Journal Bearings—Comparison Between Experimental Data and Theoretical Results,” ASME J. Tribol., 119(3), pp. 401–407. [CrossRef]
Fillon, M. , Bligoud, J. C. , and Frene, J. , 1992, “Experimental Study of Tilting-Pad Journal Bearings—Comparison With Theoretical Thermoelastohydrodynamic Results,” ASME J. Tribol., 114(3), pp. 579–588. [CrossRef]
Lund, J. W. , 1964, “Spring and Damping Coefficients for the Tilting-Pad Journal Bearing,” ASLE Trans., 7(4), pp. 342–352. [CrossRef]
Conti, R. , Frilli, A. , Galardi, E. , Meli, E. , Nocciolini, D. , Pugi, L. , Rindi, A. , and Rossin, S. , 2015, “An Efficient Quasi-Three-Dimensional Model of Tilting Pad Journal Bearing for Turbomachinery Applications,” ASME J. Vib. Acoust., 137(6), p. 061013. [CrossRef]
Rindi, A. , Rossin, S. , Conti, R. , Frilli, A. , Galardi, E. , Meli, E. , Nocciolini, D. , and Pugi, L. , 2016, “Efficient Models of Three-Dimensional Tilting Pad Journal Bearings for the Study of the Interactions Between Rotor and Lubricant Supply Plant,” ASME J. Comput. Nonlinear Dyn., 11(1), p. 011011. [CrossRef]
Suh, J. , and Palazzolo, A. , 2015, “Three-Dimensional Dynamic Model of TEHD Tilting-Pad Journal Bearing—Part I: Theoretical Modeling,” ASME J. Tribol., 137(4), p. 041703. [CrossRef]
Suh, J. , and Palazzolo, A. , 2015, “Three-Dimensional Dynamic Model of TEHD Tilting-Pad Journal Bearing—Part II: Parametric Studies,” ASME J. Tribol., 137(4), p. 041704. [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]
Tong, X. , and Palazzolo, A. , 2016, “Double Overhung Disk and Parameter Effect on Rotordynamic Synchronous Instability—Morton Effect—Part I: Theory and Modeling Approach,” ASME J. Tribol., 139(1), p. 011705. [CrossRef]
Tong, X. , and Palazzolo, A. , 2016, “Double Overhung Disk and Parameter Effect on Rotordynamic Synchronous Instability—Morton Effect—Part II: Occurrence and Prevention,” ASME J. Tribol., 139(1), p. 011706. [CrossRef]
Baldassarre, L. , Panara, D. , Panconi, S. , Meli, E. , Griffini, D. , and Mattana, A. , 2015, “Numerical Prediction and Experimental Validation of Rotor Thermal Instability,” 44th Turbomachinery Symposium, Houston, TX, Sept. 14–17. http://turbolab.tamu.edu/proc/turboproc/T44/L10.pdf
De Jongh, F. M. , and Van Der Hoeven, P. , 1998, “Application of a Heat Barrier Sleeve to Prevent Synchronous Rotor Instability,” 27th Turbomachinery Symposium, Houston, TX, Sept. 20–24. http://turbolab.tamu.edu/proc/turboproc/T27/Vol27003.pdf
Rieger, N. F. , and Crofoot, J. F. , 1977, “Vibrations of Rotating Machinery—Part I: Rotor-Bearing Dynamics,” The Vibration Institute, Clarendon Hills, IL.
Al-Ghasem, A. M. , and Childs, D. W. , 2005, “Rotordynamic Coefficients Measurements Versus Predictions for a High-Speed Flexure-Pivot Tilting-Pad Bearing (Load-Between-Pad Configuration),” ASME J. Eng. Gas Turbines Power, 128(4), pp. 896–906. [CrossRef]
Genta, G. , 1993, Vibration of Structures and Machines—Practical Aspects, Springer-Verlag, New York. [CrossRef]
Friswell, M. I. , Penny, J. E. T. , Garvey, S. D. , and Lees, A. W. , 2010, Dynamics of Rotating Machines, Cambridge University Press, Cambridge, UK. [CrossRef]
Incropera, F. P. , and DeWitt, D. P. , 1996, Fundamentals of Heat and Mass Transfer, Wiley, New York.
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.
Kirk, R. G. , and Balbahadur, A. C. , 2000, “Thermal Distortion Synchronous Rotor Instability,” Seventh International Conference on Vibrations in Rotating Machinery, Nottingham, UK, Sept. 12–14, pp. 427–438.
Zhu, Y. Y. , and Cescotto, S. , 1994, “Transient Thermal and Thermomechanical Analysis by Mixed FEM,” Comput. Struct., 53(2), pp. 275–304. [CrossRef]
Shabana, A. A. , 2013, Dynamics of Multibody Systems, Cambridge University Press, Cambridge, UK. [CrossRef]
Bergman, T. L. , Lavine, A. S. , Incropera, F. P. , and DeWitt, D. P. , 2011, Fundamentals of Heat and Mass Transfer, Wiley, Hoboken, NJ.
API, 2005, “Rotordynamic Tutorial: Lateral Critical Speeds, Unbalance Response, Stability, Train Torsionals, and Rotor Balancing,” American Petroleum Institute, Washington, DC, 2nd ed., Standard No. API STD 684. https://dyrobes.com/wp-content/uploads/2015/09/Using-Rotordynamics_linked.pdf

Figures

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Fig. 1

Tilting pad journal bearing [1]

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Fig. 2

General architecture of the steady model

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Fig. 3

General architecture of the unsteady model

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Fig. 4

SOLID and BEAM rotor models

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Fig. 6

Examples of divergent and convergent loops for a given ω

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Fig. 7

Example of a temperature profile on the outer surface of the rotor in correspondence to the bearing

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Fig. 8

Example of a solution of the steady-state thermal analysis (NDE rotor fraction)

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Fig. 10

Boundary conditions

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Fig. 9

Example of rotor orbit obtained through the unsteady model

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Fig. 11

Simplified scheme of the experimental test rig

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Fig. 13

Details of the acquisition system for the rotor temperature measurement

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Fig. 14

Test procedure to capture the onset of thermal instabilities

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Fig. 15

Filtered and unfiltered experimental unbalance responses along the vertical direction, pk − pk, for the W3 configuration at the bearings midspan

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Fig. 16

Unbalance response along the vertical direction, pk − pk, for the W3 configuration obtained through the BEAM model at the bearings midspan (unbalance force applied at the bearings midspan)

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Fig. 17

Comparison between the experimental and numerical (BEAM model) vibration phase for the W3 configuration at the bearing midspan

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Fig. 18

Comparison between the orbits obtained through the steady and the unsteady BEAM models at NDE bearing location

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Fig. 19

Unbalance responses for all the considered configurations obtained through the BEAM model at NDE bearing (unbalance force applied at the overhung to excite the rotor second critical speed)

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Fig. 20

Filtered and unfiltered experimental displacements along the vertical direction for the W3 configuration at NDE bearing

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Fig. 21

Experimental rotor temperature compared with the values obtained through the proposed model scaled with respect to Tref (W3 configuration, 13,600 rpm)

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Fig. 22

Numerical results for the W3 configuration: comparison between the steady and unsteady model. (a) Rotor vibration amplitude along the major axis of the orbit at NDE bearing for the W3 configuration, steady BEAM model, (b) rotor vibration amplitude along the major axis of the orbit at NDE bearing for the W3 configuration, steady SOLID model, (c) rotor vibration amplitude along the major axis of the orbit at NDE bearing for the W3 configuration, unsteady BEAM model, and (d) rotor vibration amplitude along the major axis of the orbit at NDE bearing for the W3 configuration, unsteady SOLID model.

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Fig. 23

Filtered and unfiltered experimental displacements along the vertical direction for the W2 configuration at NDE bearing

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Fig. 24

Experimental rotor temperature compared with the values obtained through the proposed model scaled with respect to Tref (W2 configuration, 11,400 rpm)

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Fig. 25

Numerical results for the W2 configuration: BEAM models. (a) Rotor vibration amplitude along the major axis of the orbit at NDE bearing for the W2 configuration, steady BEAM model and (b) rotor vibration amplitude along the major axis of the orbit at NDE bearing for the W2 configuration, unsteady BEAM model.

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Fig. 26

Filtered and unfiltered experimental displacements along the vertical direction for the W1 configuration at NDE bearing

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Fig. 27

Experimental rotor temperature compared with the values obtained through the proposed model scaled with respect to Tref (W1 configuration, 13,400 rpm)

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Fig. 28

Numerical results for the W1 configuration: BEAM models. (a) Rotor vibration amplitude along the major axis of the orbit at NDE bearing for the W1 configuration, steady BEAM model and (b) rotor vibration amplitude along the major axis of the orbit at NDE bearing for the W1 configuration, unsteady BEAM model.

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Fig. 29

Response amplitude as a function of the rotor speed for the three considered cases and their instability onsets

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Fig. 30

Shaft differential temperature inside bearing scaled with respect to Tref for the three considered configurations

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