Floating ring bearings (FRBs) are widely used in automobile turbochargers. However, there is no satisfying explanation of phenomenon that ring rotation speed levels off when the shaft speed reaches a certain value under low oil-supplied pressure condition. The traditional opinion that effective viscosity decreases with increasing temperature cannot completely explain this phenomenon. In this study, the air entrainment effect is introduced and evaluated using computational fluid dynamics (CFD). CFD results considering air entrainment, viscous heating, and heat transfer are compared with experimental results to evaluate each effect. The decrease in effective viscosity as a result of air–oil–thermal coupling effect is the mechanism behind the abovementioned phenomenon. This study provides calculated data and visual results of the air entrainment in low oil-supplied pressure FRB.

References

1.
Hatakenaka
,
K.
, and
Yanai
,
H.
,
2008
, “
Stability in High-Speed Floating Bush Journal Bearings at Low Supplied Pressure—Part 1: Effect of Oil Groove and Holes Into Inner Oil Film and Slope at Bush Inner Side End on Stability
,”
J. Japn. Soc. Tribol.
,
53
(
8
), pp.
536
543
.
2.
San Andres
,
L.
, and
Kerth
,
J.
,
2004
, “
Thermal Effect on the Performance of Floating Ring Bearings for Turbochargers
,”
J. Eng. Tribol.
,
218
(
J5
), pp.
437
450
.
3.
Porzig
,
D.
,
Raetz
,
H.
,
Schwarze
,
H.
, and
Seume
,
J. R.
,
2014
, “
Thermal Analysis of Small High-Speed Floating-Ring Journal Bearings
,”
11th International Conference on Turbochargers and Turbocharging
, London, May 13–14, pp. 421–436.
4.
Schweizer
,
B.
,
2010
, “
Dynamics and Stability of Turbocharger Rotors
,”
Arch. Appl. Mech.
,
80
(
9
), pp.
1017
1043
.
5.
Kohl
,
W.
,
Kreschel
,
M.
, and
Filsinger
,
D.
,
2014
, “
Experimental and Numerical Investigations on an Automotive Turbocharger With a Transparent Bearing Section
,”
11th International Conference on Turbochargers and Turbocharging
, London, May 13–14, pp. 349–359.
6.
Kirk
,
R. G.
,
Mondschein
,
B.
,
Alsaeed
,
A. A.
,
Gallimore
,
D.
,
Framk
,
A.
,
Crouch
,
J.
,
Tiller
,
M.
,
Vo
,
T.
,
Thrush
,
K.
, and
Lloyd
,
R.
,
2010
, “Influence of Turbocharger Bearing Design on Observed Linear and Nonlinear Vibration,”
ASME
Paper No. IJTC2010-41021.
7.
Boyaci
,
A.
,
Hetzler
,
H.
,
Seemann
,
W.
,
Proppe
,
C.
, and
Wauer
,
J.
,
2009
, “
Analytical Bifurcation Analysis of a Rotor Supported by Floating Ring Bearings
,”
Nonlinear Dyn.
,
57
(
4
), pp.
497
507
.
8.
Schweizer
,
B.
,
2009
, “
Oil Whirl, Oil Whip and Whirl/Whip Synchronization Occurring in Rotor Systems With Full-Floating Ring Bearings
,”
Nonlinear Dyn.
,
57
(
4
), pp.
509
532
.
9.
Kirk
,
R. G.
,
Komhauser
,
A. A.
,
Sterling
,
J.
, and
Alsaeed
,
A.
,
2010
, “
Turbocharger On-Engine Experimental Vibration Testing
,”
J. Vib. Control
,
16
(
3
), pp.
343
355
.
10.
Tatara
,
A.
,
1970
, “
An Experimental Study of the Stabilizing Effect of Floating-Bush Journal Bearings
,”
Bull. JSME
,
13
(
61
), pp.
858
863
.
11.
Song
,
Y.
,
Gu
,
C. W.
, and
Ren
,
X.
,
2015
, “
Development and Validation of a Gaseous Cavitation Model for Hydrodynamic Lubrication
,”
J. Eng. Tribol.
,
229
(
10
), pp.
1227
1238
.
12.
Song
,
Y.
,
Li
,
X. S.
, and
Gu
,
C.
,
2010
, “
Cavitation Model for Oil Film Bearings
,”
J. Tsinghua Univ.
,
50
(
7
), pp.
1047
1052
.
13.
Li
,
X. S.
,
Song
,
Y.
,
Hao
,
Z. R.
, and
Gu
,
C. W.
,
2012
, “
Cavitation Mechanism of Oil-Film Bearings and Development of a New Gaseous Cavitation Model Based on Air Solubility
,”
ASME J. Tribol.
,
134
(
3
), p.
031701
.
14.
Orcutt
,
F. K.
, and
Ng
,
C. W.
,
1968
, “
Steady-State and Dynamic Properties of the Floating-Ring Journal Bearing
,”
ASME J. Lubr. Technol.
,
90
(1), pp.
243
253
.
15.
Trippett
,
R. J.
,
1986
, “
Measured and Predicted Friction in Floating-Ring Bearings
,”
SAE
Paper No. 860075.
16.
Trippett
,
R. J.
, and
Li
,
D. F.
,
1984
, “
High-Speed Floating-Ring Bearing Test and Analysis
,”
ASLE Trans.
,
27
(
1
), pp.
73
81
.
17.
San Andres
,
L.
,
Rivadeneira
,
J. C.
,
Gjika
,
K.
,
Groves
,
C.
, and
LaRue
,
G.
,
2007
, “
Rotordynamics for Small Turbochargers Supported on Floating Ring Bearings-Highlights in Bearing Analysis and Experimental Validation
,”
ASME J. Tribol.
,
129
(
2
), pp.
391
397
.
18.
Clarke
,
D. M.
,
Fall
,
C.
,
Hayden
,
G. N.
, and
Wilkinson
,
T. S.
,
1992
, “
A Steady-State Model of a Floating Ring Bearing, Including Thermal Effects
,”
ASME J. Tribol.
,
114
(
1
), pp.
141
149
.
19.
Tsuda
,
K.
, and
Takahashi
,
T.
,
1985
, “
Observation of Oil Film Disappearance Between Shaft and Fast Rotating Bush Lubricated From Outside
,”
J. Jpn. Soc. Lubr. Eng.
,
30
(
1
), pp.
69
72
.
20.
Koeneke
,
C. E.
,
Tanaka
,
M.
, and
Motoi
,
H.
,
1995
, “
Axial Oil Film Rupture in High Speed Bearings Due to the Effect of the Centrifugal Force
,”
ASME J. Tribol.
,
117
(
3
), pp.
394
398
.
21.
Hatakenaka
,
K.
,
Tanaka
,
M.
, and
Suzuki
,
K.
,
2002
, “
A Theoretical Analysis of Floating Bush Journal Bearing With Axial Oil Film Rupture Being Considered
,”
ASME J. Tribol.
,
124
(
3
), pp.
494
505
.
22.
Hatakenaka
,
K.
,
Kasahara
,
K.
, and
Ishibashi
,
N.
,
2008
, “
Bush Driving Torque in Inner Oil Film of Floating Bush Journal Bearings With Numerical Analysis for Multi-Phase Flow Being Applied
,”
J. Jpn. Soc. Tribol.
,
53
(
9
), pp.
612
620
.
23.
San Andres
,
L.
, and
Diaz
,
S. E.
,
2003
, “
Flow Visualization and Forces From a Squeeze Film Damper Operating With Natural Air Entrainment
,”
ASME J. Tribol.
,
125
(
2
), pp.
325
333
.
24.
Renn
,
J. C.
, and
Hsiao
,
C. H.
,
2004
, “
Experimental and CFD Study on the Mass Flow-Rate Characteristic of Gas Through Orifice-Type Restrictor in Aerostatic Bearings
,”
Tribol. Int.
,
37
(
4
), pp.
309
315
.
25.
Gao
,
G. Y.
,
Yin
,
Z. W.
,
Jiang
,
D.
,
Zhang
,
X. L.
, and
Wang
,
Y. Z.
,
2016
, “
Analysis on Design Parameters of Water-Lubricated Journal Bearings Under Hydrodynamic Lubrication
,”
J. Eng. Tribol.
,
230
(
8
), pp.
1019
1029
.
26.
Song
,
Y.
, and
Gu
,
C. W.
,
2015
, “
Development and Validation of a Three-Dimensional Computational Fluid Dynamics Analysis for Journal Bearings Considering Cavitation and Conjugate Heat Transfer
,”
ASME J. Eng. Gas Turbines Power
,
137
(
12
), p.
122502
.
27.
Zhang
,
Y.
,
Sun
,
X.
, and
Huang
,
D.
,
2010
, “
A Numerical Study on Cavitation Suppression Using Local Cooling
,”
Int. J. Fluid Mach. Syst.
,
3
(
4
), pp.
292
300
.
28.
Wang
,
Y.
,
Sun
,
X. J.
,
Dai
,
Y. J.
, Wu, G. Q., Cao, Y., and Huang, D. G.,
2015
, “
Numerical Investigation of Drag Reduction by Heat-Enhanced Cavitation
,”
Appl. Therm. Eng.
,
75
(
22
), pp.
193
202
.
29.
Huang
,
D. G.
, and
Zhuang
,
Y. Q.
,
2008
, “
Temperature and Cavitation
,”
J. Mech. Eng. Sci.
,
222
(
2
), pp.
207
211
.
30.
Song
,
Y.
,
Ren
,
X.
,
Gu
,
C. W.
, and
Li
,
X. S.
,
2014
, “
Experimental and Numerical Studies of Cavitation Effects in a Tapered Land Thrust Bearing
,”
ASME J. Tribol.
,
137
(
1
), p.
011701
.
You do not currently have access to this content.