Adaptive lubricants involve binary mixture of synthetic oil and dissolved carbon dioxide (CO2). Unlike conventional lubricant oils, the lubricant viscosity not only varies with the temperature within the bearing but also can be directly adjusted through the CO2 concentration in the system. In this study, we consider the synthetic oil to be fully saturated by CO2 to investigate the maximum impacts of adaptive lubricants on the performance of a hybrid journal bearing. The adaptive lubricant analyzed for this study was the polyalkylene glycol (PAG) oil with low concentration of CO2 (<30%). A three-dimensional (3D) computational fluid dynamic (CFD) model of the bearing was developed and validated against the experimental data. The mixture composition and the resultant mixture viscosity were calculated as a function of pressure and temperature using empirical equations. The simulation results revealed that the viscosity distribution within the PAG/CO2-lubricated bearing is determined primarily by the pressure at the low operating speed. When the speed becomes higher, it is the temperature effect that dominates the viscosity distribution within the bearing. Moreover, the PAG/CO2-lubricated bearing can reduce up to 12.8% power loss than the PAG-lubricated bearing due to the low viscosity of PAG/CO2 mixture. More importantly, we have found that the PAG/CO2 can enhance the load capacity up to 19.6% when the bearing is operating at high-speed conditions.

References

References
1.
Kim
,
T. H.
, and
San Andrés
,
L.
,
2006
, “
Limits for High-Speed Operation of Gas Foil Bearings
,”
ASME J. Tribol.
,
128
(
3
), pp.
670
673
.
2.
Peng
,
Z.
, and
Khonsari
,
M.
,
2006
, “
A Thermohydrodynamic Analysis of Foil Journal Bearings
,”
ASME J. Tribol.
,
128
(
3
), pp.
534
541
.
3.
Kim
,
D.
,
2016
, “
Design Space of Foil Bearings for Closed-Loop Supercritical CO2 Power Cycles Based on Three-Dimensional Thermohydrodynamic Analyses
,”
ASME J. Eng. Gas Turbines Power
,
138
(
3
), p.
032504
.
4.
Branagan
,
M.
,
Griffin
,
D.
,
Goyne
,
C.
, and
Untaroiu
,
A.
,
2016
, “
Compliant Gas Foil Bearings and Analysis Tools
,”
ASME J. Eng. Gas Turbines Power
,
138
(
5
), p.
054001
.
5.
Benbouzid
,
S.
,
Da Silva
,
J.
,
Levine
,
J.
, and
Turpault
,
S.
,
2016
, “Active Magnetic Bearings Control System,” SKF Magnetic Mechatronics, Saint-Marcel, France, U.S. Patent No.
US9293971 B2
.
6.
Clarens
,
A.
,
Younan
,
A.
,
Wang
,
S.
, and
Allaire
,
P.
,
2010
, “
Feasibility of Gas-Expanded Lubricants for Increased Energy Efficiency in Tilting-Pad Journal Bearings
,”
ASME J. Tribol.
,
132
(
3
), p.
031802
.
7.
Weaver
,
B. K.
,
Younan
,
A. A.
,
Dimond
,
T. W.
,
Wang
,
Z.
,
Allaire
,
P.
, and
Clarens
,
A. F.
,
2013
, “
Properties and Performance of Gas-Expanded Lubricants in Tilting Pad Journal Bearings
,”
Tribol. Trans.
,
56
(
4
), pp.
687
696
.
8.
Pohrer
,
B.
,
Zuercher
,
M.
,
Westerholt
,
A.
,
Bösmann
,
A.
,
Siebert
,
D.
,
Völkl
,
J.
,
Holweger
,
W.
,
Wehrum
,
N.
,
Arlt
,
W.
,
Wasserscheid
,
P.
, and
Schlücker, E.
,
2015
, “
CO2 as a Viscosity Index Improver for Wind Turbine Oils
,”
Ind. Eng. Chem. Res.
,
54
(
21
), pp.
5810
5819
.
9.
Hauk
,
A.
, and
Weidner
,
E.
,
2000
, “
Thermodynamic and Fluid-Dynamic Properties of Carbon Dioxide With Different Lubricants in Cooling Circuits for Automobile Application
,”
Ind. Eng. Chem. Res.
,
39
(
12
), pp.
4646
4651
.
10.
Seeton, C.
,
Fahl, J.
, and
Henderson, D.
, 2000, “
Solubility, Viscosity, Boundary Lubrication and Miscibility of CO2 and Synthetic Lubricants
,” Eighth International Refrigeration Conference, West Lafayette, IN, July 25–28, pp. 417–424.
11.
Yokozeki
,
A.
,
2007
, “
Solubility Correlation and Phase Behaviors of Carbon Dioxide and Lubricant Oil Mixtures
,”
Appl. Energy
,
84
(
2
), pp.
159
175
.
12.
Bobbo
,
S.
,
Fedele
,
L.
,
Pernechele
,
F.
, and
Stryjek
,
R.
,
2008
, “
Solubility of CO2 in Commercial POE Oils With Different Standard Viscosity
,”
International Refrigeration and Air Conditioning Conference
, West Lafayette,, IN, July 14–17, Paper No.
988
.
13.
Neto
,
M. A. M.
, and
Barbosa
,
J. R.
, Jr.
,
2012
, “
Experimental and Theoretical Analysis of CO2 Absorption in Polyolester Oil Using the Pc-Saft Equation of State to Account for Nonideal Effects
,”
Ind. Eng. Chem. Res.
,
51
(
2
), pp.
1027
1035
.
14.
Feja
,
S.
, and
Hanzelmann
,
C.
,
2015
, “
Experimental Studies of Thermodynamic Properties of R744-Oil-Mixtures Up to 140 °C and 150 bar
,”
Int. J. Refrig.
,
60
, pp.
135
141
.
15.
Weaver
,
B. K.
,
Dimond
,
T. W.
,
Kaplan
,
J. A.
,
Untaroiu
,
A.
, and
Clarens
,
A. F.
,
2015
, “
Gas-Expanded Lubricant Performance and Effects on Rotor Stability in Turbomachinery
,”
ASME J. Eng. Gas Turbines Power
,
137
(
7
), p.
072601
.
16.
Weaver
,
B. K.
,
Zhang
,
Y.
,
Clarens
,
A. F.
, and
Untaroiu
,
A.
,
2015
, “
Nonlinear Analysis of Rub Impact in a Three-Disk Rotor and Correction Via Bearing and Lubricant Adjustment
,”
ASME J. Eng. Gas Turbines Power
,
137
(
9
), p.
092504
.
17.
Weaver
,
B. K.
,
Kaplan
,
J. A.
,
Clarens
,
A. F.
, and
Untaroiu
,
A.
,
2016
, “
Transient Analysis of Gas-Expanded Lubrication and Rotordynamic Performance in a Centrifugal Compressor
,”
ASME J. Eng. Gas Turbines Power
,
138
(
4
), p.
042504
.
18.
Weaver
,
B. K.
,
Fu
,
G.
,
Clarens
,
A. F.
, and
Untaroiu
,
A.
,
2015
, “Performance Analysis of Gas-Expanded Lubricants in a Hybrid Bearing Using Computational Fluid Dynamics,”
ASME
Paper No. IMECE2015-53735.
19.
Chien
,
S. Y.
,
Untaroiu
,
A.
, and
Cramer
,
M. S.
, 2016, “Numerical Modeling of Gas-Expanded Lubricants in Hybrid Bearings,” 24th International Congress of Theoretical and Applied Mechanics, Montreal, QC, Canada, Aug. 21–26, Paper No. 138831.
20.
Jeng
,
Y.-R.
,
Chang
,
C.-S.
, and
Wang
,
C.-C.
,
2001
, “
Vapor Pressure of R-410a/Oil and R-407c/Oil Mixtures
,”
Appl. Therm. Eng.
,
21
(
8
), pp.
863
870
.
21.
Youbi-Idrissi
,
M.
,
Bonjour
,
J.
,
Terrier
,
M.
,
Meunier
,
F.
, and
Marvillet
,
C.
,
2003
, “
Solubility of CO2 in a Synthetic Oil
,”
21st International Congress of Refrigeration, Washington, DC
, Aug. 17–22, pp.
1
9
.
22.
Grunberg
,
L.
, and
Nissan
,
A. H.
,
1949
, “
Mixture Law for Viscosity
,”
Nature
,
164
, pp.
799
800
.
23.
Reid
,
R. C.
,
Prausnitz
,
J. M.
, and
Poling
,
B. E.
,
1987
,
The Properties of Gases and Liquids
,
McGraw-Hill
, New York.
24.
Franchek
,
N. M.
, and
Childs
,
D. W.
,
1994
, “
Experimental Test Results for Four High-Speed, High-Pressure, Orifice-Compensated Hybrid Bearings
,”
ASME J. Tribol.
,
116
(
1
), pp.
147
153
.
25.
Ockendon
,
J.
,
1995
,
Viscous Flow
, Vol.
13
,
Cambridge University Press
, New York.
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