Using the experience acquired within our lab in terms of both thermohydrodynamic (THD) and thermoelastohydrodynamic (TEHD) numerical simulations, a new THD code has been improved by adding the possibility of taking into account geometrical defects, and particularly scratches, which are often discovered by turbine users during maintenance operations. To examine this issue, two numerical codes were coupled to provide the TEHD analysis presented in this work. To validate the numerical results, experimental tests were conducted using the Pprime Institute bearing test rig. The performance of the same two-lobe journal bearing (preload 0.524) as used in a previous study, lubricated with ISO VG 46 oil, was evaluated. Scratches of different depths (varying as a function of the radial clearance) were directly machined onto the shaft. TEHD solutions and experimental data were compared for various rotational speeds and applied loads. Pressure and temperature comparisons for the three scratch depths show good correlation, and give the expected results for cases with a scratch. It was also found that the asymmetry in the pressure field created by the presence of a scratch led to a slight misalignment. The comparisons were improved by taking into account this misalignment, using the balance of momentum.

References

References
1.
Ferron
,
J.
,
Frêne
,
J.
, and
Boncompain
,
R.
,
1983
, “
A Study of the Thermohydrodynamic Performance of a Plain Journal Bearing. Comparison Between Theory and Experiments
,”
ASME J. Lubr. Technol.
,
105
(
3
), pp.
422
428
.
2.
Ferron
,
J.
,
1980
, “
Contribution à l'étude des phénomènes thermiques dans les paliers hydrodynamiques
,” Ph.D. thesis, University of Poitiers, Poitiers, France.
3.
Boncompain
,
R.
, and
Frêne
,
J.
,
1979
, “
Thermodynamic of Finite Journal Bearing—Static and Dynamic Characteristics
,”
Sixth Leeds-Lyon Symposium on Tribology
, pp.
34
41
.
4.
Boncompain
,
R.
,
Fillon
,
M.
, and
Frêne
,
J.
,
1986
, “
Analysis of Thermal Effects in Hydrodynamic Bearings
,”
ASME J. Tribol.
,
108
(
2
), pp.
219
224
.
5.
Khonsari
,
M.
, and
Wang
,
S.
,
1991
, “
On the Fluid-Solid Interaction in Reference to Thermoelastohydrodynamic Analysis of Journal Bearings
,”
ASME J. Tribol.
,
113
(
2
), pp.
398
404
.
6.
Monmousseau
,
P.
,
Fillon
,
M.
, and
Frêne
,
J.
,
1997
, “
Transient Thermaloelastohydrodynamic Study of Tilting-Pad Journal Bearings—Comparison Between Experimental Data and Theoretical Results
,”
ASME J. Tribol.
,
119
(
3
), pp.
401
407
.
7.
Monmousseau
,
P.
,
Fillon
,
M.
, and
Frêne
,
J.
,
1998
, “
Transiant Thermoelastohydrodynamic Study of Tilting-Pad Journal Bearings—Application to Bearing Seizure
,”
ASME J. Tribol.
,
120
(
2
), pp.
319
324
.
8.
Zhang
,
C.
,
Yi
,
Z.
, and
Zhang
,
Z.
,
2000
, “
THD Analysis of High Speed Heavily Loaded Journal Bearings Including Thermal Deformation, Mass Conserving Cavitation, and Turbulent Effects
,”
ASME J. Tribol.
,
122
(
3
), pp.
597
602
.
9.
Dobrica
,
M.
,
Fillon
,
M.
, and
Maspeyrot
,
P.
,
2006
, “
Mixed Elastohydrodynamic Lubrication in a Partial Journal Bearing—Comparison Between Deterministic and Stochastic Models
,”
ASME J. Tribol.
,
128
(
4
), pp.
778
788
.
10.
Bouyer
,
J.
, and
Fillon
,
M.
,
2002
, “
An Experimental Analysis of the Misalignment Effects on Hydrodynamic Plain Journal Bearing Performances
,”
ASME J. Tribol.
,
124
(
2
), pp.
313
319
.
11.
Bouyer
,
J.
, and
Fillon
,
M.
,
2003
, “
Improvement of the THD Performance of a Misaligned Plain Journal Bearing
,”
ASME J. Tribol.
,
125
(
2
), pp.
334
342
.
12.
Broeder
,
J. J.
, and
Heijnekamp
,
J. W.
,
1965
, “
Abrasive Wear of Journal Bearings by Particles in the Oil (Apparatus, Experiments and Observations)
,”
Proc. Inst. Mech. Eng.
,
180
(
11
), pp.
21
31
.
13.
Dadouche
,
A.
, and
Conlon
,
M.
,
2016
, “
Operational Performance of Textured Journal Bearings Lubricated With a Contaminated Fluid
,”
Tribol. Int.
,
93
, pp.
377
389
.
14.
Sep
,
J.
,
Tomczewski
,
L.
,
Galda
,
L.
, and
Dzierwa
,
A.
,
2017
, “
The Study on Abrasive Wear of Grooved Journal Bearings
,”
Wear
,
376–377
, pp.
54
62
.
15.
Branagan
,
L.
,
2006
, “
Toward a Quantitative Analysis of Journal and Bearing Scratches
,”
Fifth EDF and LMS Workshop on Bearing Behaviour Under Unusual Operating Conditions, Poitiers, France
, pp.
1
9
.
16.
Dobrica
,
M.
, and
Fillon
,
M.
,
2012
, “
Performance Degradation in Scratched Journal Bearing
,”
Tribol. Int.
,
51
, pp.
1
10
.
17.
Hélène
,
M.
,
Beaurain
,
J.
, and
Raud
,
X.
,
2013
, “
Impact of Scratches in Tilting Pad Journal Bearings—Influence of the Geometrical Characteristics of Scratches
,”
12th EDF and Pprime Workshop on Solutions for Performance Improvement and Friction Reduction of Journal and Thrust Bearings, Poitiers, France
, pp.
1
12
.
18.
Giraudeau
,
C.
,
Bouyer
,
J.
,
Fillon
,
M.
,
Hélène
,
M.
, and
Beaurain
,
J.
,
2017
, “
Experimental Study of the Influence of Scratches on the Performance of a Two-Lobe Journal Bearing
,”
STLE Tribol. Trans.
,
60
(
5
), pp.
942
955
.
19.
Khonsari
,
M.
, and
Beaman
,
J.
,
1985
, “
Thermohydrodynamic Analysis of Laminar Incompressible Journal Bearings
,”
ASLE Trans.
,
29
(
2
), pp.
141
150
.
20.
Braun
,
M.
, and
Hendricks
,
R.
,
1984
, “
An Experimental Investigation of the Vaporous/Gaseous Cavity Characteristics in an Eccentric Journal Bearing
,”
ASLE Trans.
,
27
(
1
), pp.
1
14
.
21.
Cristea
,
C.
,
Bouyer
,
J.
, and
Fillon
,
M.
,
2011
, “
Pressure and Temperature Field Measurements of a Lightly Loaded Circumferential Groove Journal Bearing
,”
STLE Tribol. Trans.
,
54
(
5
), pp.
806
823
.
You do not currently have access to this content.