The journal is the part of a shaft that is inside a fluid film bearing and is usually assumed to be circumferentially isothermal. Recent work has shown that under certain vibration conditions, a significant temperature difference (ΔT) can develop around the journal circumference. The ΔT may cause the shaft to bend leading to a synchronous vibration instability problem, termed the “Morton effect” (ME). A test rig was developed to verify the asymmetric journal temperature of the ME and its prediction using a five-pad tilting pad journal bearing (TPJB) operating with an eccentric shaft to replicate a circular vibration orbit. The bearing is tested at various conditions including: supply oil temperature at 28 °C and 41 °C, bearing operating eccentricities of zero and 32%Cb, and rotor speed up to 5500 rpm. The journal temperature distribution is recorded with 20 sensors located around the journal circumference, and the measurements provide a benchmark for predictions from a time transient model with the three-dimensional (3D) fluid and solid finite element method (FEM), and with a simplified ME prediction approach using only steady-state results. The test results follow the predictions exhibiting a sinusoidal-like temperature profile around the circumference with an angular lag of the hot spot location behind the high spot location (angular position on the rotor that arrives at the minimum film thickness condition each rotation) by a speed-dependent angle. Increasing the supply oil temperature reduced the journal ΔT, while increasing the bearing operating eccentricity increased the journal ΔT. The agreement between the test and predicted results is significantly better for the 3D FEM transient model than for the steady-state-based model in terms of journal ΔT and hot spot position. An improved version of the latter approach is proposed and yields significantly better correlation with the test measurements.

References

1.
Fillon
,
M.
,
Bligoud
,
J.
, and
Frene
,
J.
,
1992
, “
Experimental Study of Tilting-Pad Journal Bearings-Comparison With Theoretical Thermoelastohydrodynamic Results
,”
ASME J. Tribol.
,
114
(
3
), pp.
579
587
.
2.
Dowson
,
D.
,
Hudson
,
J.
,
Hunter
,
B.
, and March, C.,
1966
, “
Paper 3: An Experimental Investigation of the Thermal Equilibrium of Steadily Loaded Journal Bearings
,”
Proc. Inst. Mech. Eng.
,
181
(
2
), pp.
70
80
.
3.
Paranjpe
,
R.
, and
Han
,
T.
,
1995
, “
A Transient Thermohydrodynamic Analysis Including Mass Conserving Cavitation for Dynamically Loaded Journal Bearings
,”
ASME J. Tribol.
,
117
(
3
), pp.
369
378
.
4.
Knight
,
J.
, and
Barrett
,
L.
,
1988
, “
Analysis of Tilting Pad Journal Bearings With Heat Transfer Effects
,”
ASME J. Tribol.
,
110
(
1
), pp.
128
133
.
5.
Khonsari
,
M.
, and
Beaman
,
J.
,
1986
, “
Thermohydrodynamic Analysis of Laminar Incompressible Journal Bearings
,”
ASLE Trans.
,
29
(
2
), pp.
141
150
.
6.
Morton
,
P. G.
,
1975
, “
Some Aspects of Thermal Instability in Generators
,” G.E.C. Internal Report, Report No. S/W40 u183.
7.
Hesseborn
,
B.
,
1978
, “
Measurements of Temperature Unsymmetries in Bearing Journal Due to Vibration
,” Internal Report.
8.
Balbahadur
,
A. C.
, and
Kirk
,
R.
,
2004
, “
Part I—Theoretical Model for a Synchronous Thermal Instability Operating in Overhung Rotors
,”
Int. J. Rotating Mach.
,
10
(
6
), pp.
469
475
.
9.
de Jongh
,
F.
, and
Morton
,
P. G.
,
1994
, “
The Synchronous Instability of a Compressor Rotor Due to Bearing Journal Differential Heating
,”
ASME
Paper No. 94-GT-035.
10.
Keogh
,
P.
, and
Morton
,
P.
,
1993
, “
Journal Bearing Differential Heating Evaluation With Influence on Rotordynamic Behaviour
,”
Proc. R. Soc. London, Ser. A
,
441
(
1913
), pp.
527
548
.
11.
Keogh
,
P.
, and
Morton
,
P.
,
1994
, “
The Dynamic Nature of Rotor Thermal Bending Due to Unsteady Lubricant Shearing Within a Bearing
,”
Proc. R. Soc. London, Ser. A
,
445
(
1924
), pp.
273
290
.
12.
Murphy
,
B.
, and
Lorenz
,
J.
,
2010
, “
Simplified Morton Effect Analysis for Synchronous Spiral Instability
,”
ASME J. Vib. Acoust.
,
132
(
5
), p.
051008
.
13.
Suh
,
J.
, and
Palazzolo
,
A.
,
2014
, “
Three-Dimensional Thermohydrodynamic Morton Effect Simulation—Part I: Theoretical Model
,”
ASME J. Tribol.
,
136
(
3
), p.
031706
.
14.
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
.
15.
Tong
,
X.
,
Palazzolo
,
A.
, and
Suh
,
J.
,
2016
, “
Rotordynamic Morton Effect Simulation With Transient, Thermal Shaft Bow
,”
ASME J. Tribol.
,
138
(
3
), p.
031705
.
16.
Lee
,
J.
, and
Palazzolo
,
A.
,
2012
, “
Morton Effect Cyclic Vibration Amplitude Determination for Tilt Pad Bearing Supported Machinery
,”
ASME J. Tribol.
,
135
(
1
), p.
011701
.
17.
Lorenz
,
J.
, and
Murphy
,
B.
,
2011
, “
Case Study of Morton Effect Shaft Differential Heating in a Variable-Speed Rotating Electric Machine
,”
ASME
Paper No. GT2011-45228.
18.
Panara
,
D.
,
Panconi
,
S.
, and
Griffini
,
D.
,
2015
, “
Numerical Prediction and Experimental Validation of Rotor Thermal Instability
,”
44th Turbomachinery Symposium
, College Station, TX, Sept. 14–17, pp. 1–18.
19.
Tong
,
X.
,
Palazzolo
,
A.
, and
Suh
,
J.
,
2017
, “
A Review of the Rotordynamic Thermally Induced Synchronous Instability (Morton) Effect
,”
ASME Appl. Mech. Rev.
, epub.
20.
Schmied
,
J.
,
Pozivil
,
J.
, and
Walch
,
J.
,
2008
, “
Hot Spots in Turboexpander Bearings: Case History, Stability Analysis, Measurements and Operational Experience
,”
ASME
Paper No. GT2008-51179.
21.
Gomiciaga
,
R.
, and
Keogh
,
P.
,
1999
, “
Orbit Induced Journal Temperature Variation in Hydrodynamic Bearings
,”
ASME J. Tribol.
,
121
(
1
), pp.
77
84
.
22.
Tong
,
X.
, and
Palazzolo
,
A.
,
2016
, “
The Influence of Hydrodynamic Bearing Configuration on Morton Effect
,”
ASME
Paper No. GT2016-56654.
23.
Gadangi
,
R.
,
Palazzolo
,
A.
, and
Kim
,
J.
,
1996
, “
Transient Analysis of Plain and Tilt Pad Journal Bearings Including Fluid Film Temperature Effects
,”
ASME J. Tribol.
,
118
(
2
), pp.
423
430
.
24.
Heinrich
,
J.
, Huyakorn, P., Zienkiewicz, O., and Mitchell, A.,
1977
, “
An ‘Upwind’ Finite Element Scheme for Two-Dimensional Convective Transport Equation
,”
Int. J. Numer. Methods Eng.
,
11
(
1
), pp.
131
143
.
25.
Ettles
,
C.
, and
Cameron
,
A.
,
1968
, “
Considerations of Flow Across a Bearing Groove
,”
ASME J. Lubr. Technol.
,
90
(
1
), pp.
312
319
.
26.
Heshmat
,
H.
, and
Pinkus
,
O.
,
1986
, “
Mixing Inlet Temperatures in Hydrodynamic Bearings
,”
ASME J. Tribol.
,
108
(
2
), pp.
231
244
.
27.
Young
,
W. C.
, and
Budynas
,
R. G.
,
2002
,
Roark's Formulas for Stress and Strain
, Vol.
7
,
McGraw-Hill
,
New York
.
28.
de Jongh
,
F.
, and
Van Der Hoeven
,
P.
, eds.,
1998
, “
Application of a Heat Barrier Sleeve to Prevent Synchronous Rotor Instability
,”
27th Turbomachinery Symposium
, College Station, TX, Sept. 20–24, pp.
17
26
.
29.
Corcoran
,
J.
,
Rea
,
H.
, and
Cornejo
,
G.
,
1997
, “
Discovering, the Hard Way, How a High Performance Coupling Influenced the Critical Speeds and Bearing Loading of an Overhung Radial Compressor—A Case History
,”
26th Turbomachinery Symposium
, College Station, TX, Sept. 14–16, pp. 67–78.
30.
Suh
,
J.
, and
Palazzolo
,
A.
,
2014
, “
Three-Dimensional Thermohydrodynamic Morton Effect Analysis—Part II: Parametric Studies
,”
ASME J. Tribol.
,
136
(
3
), p.
031707
.
31.
Carter
,
C. R.
, and
Childs
,
D. W.
,
2009
, “
Measurements versus Predictions for the Rotordynamic Characteristics of a Five-Pad Rocker-Pivot Tilting-Pad Bearing in Load-Between-Pad Configuration
,”
ASME J. Eng. Gas Turbines Power
,
131
(
1
), p.
012507
.
32.
Kulhanek
,
C. D.
, and
Childs
,
D. W.
,
2012
, “
Measured Static and Rotordynamic Coefficient Results for a Rocker-Pivot, Tilting-Pad Bearing With 50 and 60% Offsets
,”
ASME J. Eng. Gas Turbines Power
,
134
(
5
), p.
052505
.
33.
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
.
You do not currently have access to this content.