The traditional method for hydrodynamic journal bearing analysis usually applies the lubrication theory based on the Reynolds equation and suitable empirical modifications to cover turbulence, heat transfer, and cavitation. In cases of complex bearing geometries for steam and heavy-duty gas turbines, this approach has its obvious restrictions in regard to detail flow recirculation, mixing, mass balance, and filling level phenomena. These limitations could be circumvented by applying a computational fluid dynamics (CFD) approach, resting closer to the fundamental physical laws. The present contribution reports about the state of the art of such a fully three-dimensional multiphase-flow CFD approach, including cavitation and air entrainment for high-speed turbomachinery journal bearings. It has been developed and validated using experimental data. Due to the high ambient shear rates in bearings, the multiphase-flow model for journal bearings requires substantial modifications in comparison to common two-phase flow simulations. Based on experimental data, it is found, that particular cavitation phenomena are essential for the understanding of steam and heavy-duty-type gas turbine journal bearings.

References

References
1.
Bloch
,
H. P.
, and
Singh
,
M. P.
, 2009,
Steam Turbines
,
2nd ed.
,
McGraw-Hill
,
New York.
2.
Boyce
,
M. P.
, 2010,
Handbook for Cogeneration and Combined Cycle Power Plants
,
ASME
,
New York
.
3.
Verstege
,
S.
, and
Boeckel
,
F.
, 2010,
Stationäre Gasturbinen
,
2nd ed.
,
C.
Lechner
and
J.
Seume
, eds.,
Springer
,
Berlin
, Chap. 22.
4.
Pinkus
,
O.
, and
Sternlicht
,
B.
, 1961,
Theory of Hydrodynamic Lubrication
,
McGraw-Hill
,
New York.
5.
Kirk
,
R. G.
,
Raju
,
K. V. S.
, and
Ramesh
,
K.
, 1999, “
PC-Based Analysis of Turbomachinery Vibration
,”
Shock Vib. Dig.
,
31
(
6
), pp.
449
454
.
6.
Mittwollen
,
N.
, and
Rückert
,
A.
, 1991,
Verbesserung der Berechnungsgrundlagen für schnellaufende, hochbelastete Mehrgleitflächen- und Radialkippsegmentlager. Abschlussbericht zum BMFT-Verbundprojekt “Gleitlageruntersuchungen”
,
TU Braunschweig
,
Braunschweig
.
7.
Floberg
,
L.
, and
Jakobsson
,
B.
, 1957, “
The Finite Journal Bearing Considering Vaporization
,”
Chalmers University of Technology
,
Gothenburg
,
Sweden
, Transaction No. 109.
8.
Guo
,
Z.
,
Hirano
,
T.
, and
Kirk
,
R. G.
, 2005, “
Application of CFD Analysis for Rotating Machinery—Part I: Hydrodynamic, Hydrostatic Bearings and Squeeze Film Damper
,”
ASME J. Eng. Gas Turbines Power
,
127
, pp.
445
451
.
9.
Schnerr
,
G. H.
,
Adam
,
S.
,
Lanzenberger
,
K.
, and
Schulz
,
R.
, 1995, “
Multiphase Flows: Condensation and Cavitation Problems
,”
Computational Fluid Dynamics Review
,
Wiley
,
New York
, pp.
614
640
.
10.
aus der Wiesche
,
S.
, “
Bubble Nucleation, Growth, and Deformation in Shear Flows
,”
J. Non-Equil. Thermodyn.
,
31
, pp.
205
230
.
11.
OpenCFD Limited, 2010, OpenFOAM User Guide Version 1.7.1, Free Software Foundation, Inc., Boston.
12.
Brennen
,
C.
, 2009,
Fundamentals of Multiphase Flow
,
Cambridge University Press
,
Cambridge, England
.
13.
Sauer
,
J.
,
Winkler
,
G.
, and
Schnerr
,
G. H.
, 1999, “
Kavitation und Kondensation – Physikalische Modellbildung und numerische Umsetzung
,”
Chem.-Ing.-Tech.
,
71
, pp.
1399
1402
.
14.
Durst
,
F.
, 2006,
Grundlagen der Strömungsmechanik
,
Springer
,
Berlin.
15.
Shih
,
T.-H.
,
Liou
,
W. W.
,
Shabbir
,
A.
,
Yang
,
Z.
, and
Zhu
,
J.
, 1995, “
A New k-ɛ Eddy Viscosity Model for High Reynolds Number Turbulent Flows
,”
Comput. Fluids
,
24
, pp.
227
238
.
16.
Uhkötter
,
S.
,
Becker
,
A.
,
Czajka
,
H.
,
aus der Wiesche
,
S.
, and
Brasseler
,
S.
, 2012, “
Grundlagenuntersuchung zu den Strömungsverhältnissen in hochtourigen Turbinengleitlagern: Strömung in einem Konfusor mit einseitig bewegter Berandung
,”
Forsch. Ingenieurwes.
,
76
, pp.
1
13
.
17.
Yuan
,
W.
,
Sauer
,
J.
, and
Schnerr
,
G. H.
, “
Modeling and Computation of Unsteady Cavitation Flows in Injection Nozzles
,”
Mec. Ind.
,
2
, pp.
383
394
.
18.
Sauer
,
J.
, “
Instationär kavitierende Strömungen - Ein neues Modell, basierend auf Front Capturing (VoF) und Blasendynamik
,” Ph.D. thesis, University of Karlsruhe, Karlsruhe, Germany.
19.
Kühl
,
S.
, and
Schüler
,
E.
, 2006, “
Untersuchung der statischen und dynamischen Eigenschaften eines Tragspiegel-Gasturbinenlagers Bauart Siemens PG ohne und mit Turbulenznuten
,” unpublished technical report.
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