Research Papers

A Thermoelastohydrodynamic Analysis for the Static Performance of High-Speed—Heavy Load Tilting-Pad Journal Bearing Operating in the Turbulent Flow Regime and Comparisons to Test Data

[+] Author and Article Information
Hirotoshi Arihara

Kobe Steel LTD,
Kobe-city 651-2271, Hyogo, Japan
e-mail: arihara.hirotoshi@kobelco.com

Yuki Kameyama, Yoshitaka Baba

Kobe Steel LTD.,
Takasago-city 676-8670, Hyogo, Japan

Luis San Andrés

Fellow ASME
Mechanical Engineering Department,
Texas A&M University,
College Station, TX 77843

Manuscript received July 5, 2018; final manuscript received July 17, 2018; published online October 4, 2018. Editor: Jerzy T. Sawicki.

J. Eng. Gas Turbines Power 141(2), 021023 (Oct 04, 2018) (9 pages) Paper No: GTP-18-1445; doi: 10.1115/1.4041130 History: Received July 05, 2018; Revised July 17, 2018

Tilting-pad journal bearings (TPJBs) ensure rotordynamic stability that could otherwise produce dangerously large amplitude rotor oil-whirl/whip motions in high-speed rotating machinery. Currently, highly efficient turbo compressors demand an ever increasing rotor surface speed and specific load on its support bearings. The accurate prediction of bearing performance is vital to guarantee reliable products, specifically with regard to reducing maximum bearing pad temperature and drag power losses, and operating with the least flow rate while still maximizing load capacity. The hydrodynamic pressure and heat generation in an oil film acting on a bearing pad produce significant mechanical and thermal deformations that change the oil film geometry (clearance and preload) to largely affect the bearing performance, static, and dynamic. In addition, a high surface speed bearing often operates in the turbulent flow regime that produces a notable increase in power loss and a drop in maximum pad temperature. This paper details a thermoelastohydrodynamic (TEHD) analysis model applied to TPJBs, presents predictions for their steady-load performance, and discusses comparisons with experimental results to validate the model. The test bearing has four pads with a load between pads configuration; its length L = 76.2 mm and shaft diameter D = 101.6 mm (L/D = 0.75). The rotor top speed is 22.6 krpm, i.e., 120 m/s surface speed, and the maximum specific load is 2.94 MPa for an applied load of 23 kN. The test procedure records shaft speed and applied load, oil supply pressure/temperature and flow rate, and also measures the pads' temperature and shaft temperature, as well as the discharge oil (sump) temperature. The TEHD model couples a generalized Reynolds equation for the hydrodynamic pressure generation with a three-dimensional energy transport equation for the film temperature. The pad mechanical deformation due to pressure utilizes the finite elemental method, whereas an analytical model estimates thermally induced pad crowning deformations. For operation beyond the laminar flow regime, the analysis incorporates the eddy viscosity concept for fully developed turbulent flow operation. Current predictions demonstrate the influence of pressure and temperature fields on the pads mechanical and thermally induced deformation fields and also show static performance characteristics such as bearing power loss, flow rate, and pad temperatures. The comparisons of test results and analysis results reveal that turbulent flow effects significantly reduce the pads' maximum temperature while increasing the bearing power loss. Turbulent flow mixing increases the diffusion of thermal energy and makes more uniform the temperature profile across the film.

Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.


Gardner, W. W. , and Ulschmid, J. G. , 1974, “ Turbulence Effects in Two Journal Bearing Applications,” ASME J. Lubr. Technol., 96(1), pp. 15–21. [CrossRef]
Gethin, D. T. , and Medwell, J. O. , 1985, “ An Experimental Investigation Into the Thermohydrodynamic Behavior of a High Speed Cylindrical Bore Journal Bearing,” ASME J. Tribol., 107(4), pp. 538–543. [CrossRef]
Hopf, G. , and Schüler, D. , 1989, “ Investigations on Large Turbine Bearings Working Under Transitional Conditions Between Laminar and Turbulent Flow,” ASME J. Tribol., 111(4), pp. 628–634. [CrossRef]
Mittwollen, N. , and Glienicke, J. , 1990, “ Operating Conditions of Multi-Lobe Journal Bearings Under High Thermal Loads,” ASME J. Tribol., 112(2), pp. 330–340. [CrossRef]
Mikami, M. , Kumagai, M. , Uno, S. , and Hashimoto, H. , 1998, “ Static and Dynamic Characteristics of Rolling-Pad Journal Bearings in Super-Laminar Flow Regime,” ASME J. Tribol., 110, pp. 73–79. [CrossRef]
Ng, C. W. , and Pan, C. H. T. , 1965, “ A Linearized Turbulent Lubrication Theory,” ASME J. Basic Eng., 87(3) pp. 675–688. [CrossRef]
Elrod, H. G. , and Ng, C. W. , 1967, “ A Theory of Turbulent Fluid Films and Its Applications to Bearings,” ASME J. Lubr. Technol., 89(3), pp. 346–362. [CrossRef]
Taniguchi, S. , Makino, T. , Takeshita, K. , and Ichimura, T. , 1990, “ A Thermohydrodynamic Analysis of Large Tilting-Pad Journal Bearing in Laminar and Turbulent Flow Regimes With Mixing,” ASME J. Tribol., 112(3), pp. 542–548. [CrossRef]
Bouard, L. , Fillon, M. , and Frene, J. , 1996, “ Thermohydrodynamic Analysis of Tilting-Pad Journal Bearings Operating in Turbulent Flow Regime,” ASME J. Tribol., 118, pp. 225–231. [CrossRef]
Bouard, L. , Fillon, M. , and Frene, J. , 1996, “ Comparison Between Three Turbulent Models—Application to Thermohydrodynamic Performances of Tilting-Pad Journal Bearings,” Tribol. Int., 29(1), pp. 11–18. [CrossRef]
Tanaka, M. , and Hatakenaka, K. , 2004, “ Turbulent Thermohydrodynamic Lubrication Models Compared With Measurements,” Proc. Inst. Mech. Eng. Part J: J. Eng. Tribol., 218(5), pp. 391–399. [CrossRef]
Fillon, M. , Bligoud, J. C. , and Frene, J. , 1992, “ Experimental Study of Tilting Pad Journal Bearings: Comparison With Theoretical Thermoelastohydro-Dynamic Results,” ASME J. Tribol., 114(3), pp. 579–588. [CrossRef]
Desbordes, H. , Fillon, M. , Frene, J. , and Chan Hew Wai, C. , 1995, “ The Effects of Three Dimensional Pad Deformations on Tilting-Pad Journal Bearings Under Dynamic Loading,” ASME J. Tribol., 117(3), pp. 379–384. [CrossRef]
Earles, L. L. , Palazzolo, A. B. , and Armentrout, R. W. , 1990, “ A Finite Element Approach to Pad Flexibility in Tilt Pad Journal Bearings—Part I: Single Pad Analysis,” ASME J. Tribol., 112(2), pp. 169–177. [CrossRef]
Earles, L. L. , Palazzolo, A. B. , and Armentrout, R. W. , 1990, “ A Finite Element Approach to Pad Flexibility in Tilt Pad Journal Bearings—Part II: Assembled Bearing and System Analysis,” ASME J. Tribol., 112(2), pp. 178–182. [CrossRef]
He, M. , 2003, “ Thermoelastohydrodynamic Analysis of Fluid Film Journal Bearings,” Ph.D. thesis, University of Virginia, Charlottesville, VA. https://elibrary.ru/item.asp?id=5710650
He, M. , Cloud, C. H. , and Byrne, J. M. , 2005, “ Fundamentals of Fluid Film Journal Bearing Operation and Modeling,” 34th Turbomachinery Symposium, Sept. 12–15, pp. 155–175.
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, p. 041704. [CrossRef]
Brugier, D. , and Pascal, M. T. , 1989, “ Influence of Elastic Deformations of Turbo-Generator Tilting Pad Bearings on the Static Behavior and on the Dynamic Coefflcients in Different Designs,” ASME J. Tribol., 111(2), pp. 364–371. [CrossRef]
San Andrés, L. , and Li, Y. , 2015, “ Effect of Pad Flexibility on the Performance of Tilting Pad Journal Bearings—Benchmarking a Predictive Model,” ASME J. Eng. Gas Turbines Power, 137(12), p. 122503. [CrossRef]
Hagemann, T. , Kukla, S. , and Schwarze, H. , 2013, “ Measurement and Prediction of the Static Operating Conditions of a Large Turbine Tilting-Pad Bearing Under High Circumferential Speeds and Heavy Loads,” ASME Paper No. GT2013-95004,
Sano, T. , Magoshi, R. , Shinohara, T. , Yoshimine, C. , Nishioka, T. , Tochitani, N. , and Sumi, Y. , 2015, “ Confirmation of Performance and Reliability of Direct Lubricated Tilting Two Pads Bearing,” Proc. Inst. Mech. Eng. Part J: J. Eng. Tribol., 229(8), pp. 1011–1021. [CrossRef]
Dowson, D. , 1962, “ A Generalized Reynolds Equation for Fluid-Film Lubrication,” Int. J. Mech. Sci., 4(2), pp. 159–170. [CrossRef]
Mitsui, J. , Hori, Y. , and Tanaka, M. , 1983, “ Thermohydrodynamic Analysis of Cooling Effect of Supply Oil in Circular Journal Bearing,” ASME J. Lubr. Technol., 105(3), pp. 414–420. [CrossRef]
Safar, Z. , and Szeri, A. Z. , 1974, “ Thermohydrodynamic Lubrication in Laminar and Turbulent Regimes,” ASME J. Lubr. Technol., 96(1), pp. 48–57. [CrossRef]
Suganami, T. , and Szeri, A. Z. , 1979, “ A Thermohydrodynamic Analysis of Journal Bearings,” ASME J. Lubr. Technol., 101(1), pp. 21–27. [CrossRef]
Abdollahi, A. , 2017, “ A Computational Model for Tilting Pad Journal Bearings: Accounting for Thermally Induced Pad Deformations and Improving a Feeding Groove Thermal Mixing Model,” M.S. thesis, Mechanical Engineering, Texas A&M University, College Station, TX. https://oaktrust.library.tamu.edu/bitstream/handle/1969.1/155408/LI-THESIS-2015.pdf?sequence=1


Grahic Jump Location
Fig. 1

A geometry of a four pads TPJB and coordinate system

Grahic Jump Location
Fig. 2

Pad finite element method structure model and constraint condition [21]

Grahic Jump Location
Fig. 3

Static condensation of pad stiffness matrix: (a) original pad FE model (22,572 DOFs) and (b) reduced pad FE model (836 DOFs)

Grahic Jump Location
Fig. 4

Schematic view of thermally induced deformations in a pad and journal [28]

Grahic Jump Location
Fig. 5

Cross section of bearing test rig

Grahic Jump Location
Fig. 6

Photograph of test rig opened to showcase test bearing and support bearings

Grahic Jump Location
Fig. 7

Location of thermocouples in pads of test bearing: (a) location of thermocouples in bearing side view and (b) axial and circumferential position of thermocouples

Grahic Jump Location
Fig. 8

Shaft surface temperature measurement points

Grahic Jump Location
Fig. 9

Temperature distribution in bearing pads (measured and predictions) and pad deformations for test bearing. Journal surface speed =120 m/s, specific load =2.94 MPa: (a) measured and predicted temperatures in pads and (b) thermally induced and pressure elastic deformation of the pads.

Grahic Jump Location
Fig. 10

Predicted max. Reynolds number versus journal surface speed (specific load =2.94 MPa).

Grahic Jump Location
Fig. 11

Predicted temperatures at midplane of loaded pad (#4) for operation with journal surface speed =120 m/s, specific load =2.94 MPa: (a) laminar flow model, (b) turbulent flow model, and (c) temperature distribution across film of pad#4 trailing edge

Grahic Jump Location
Fig. 12

Measured and predictions for bearing static performance versus surface speed (specific load =2.94 MPa): (a) maximum pad#4 temperature (85%), (b) journal surface temperature, (c) bearing drag power loss, and (d) bearing oil flow rate



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In