Abstract

This paper focuses on an integral gas-film lubricated bearing concept developed to enable the oil-free operation of super-critical carbon dioxide (sCO2) turbomachinery. The externally pressurized tilting pad bearing concept possesses a flexible bearing support with an integral hermetically sealed squeeze film damper. Unlike the past concepts using modular hermetic squeeze film dampers presented, the bearing design in this work utilizes advanced manufacturing methods to yield an integral single piece design in efforts to reduce space envelope, cost, and improve overall design reliability. The paper advances a detailed description of the bearing design and identification of bearing support force coefficients. Nonrotating benchtop tests show the influence of vibration amplitude, frequency, and damper cavity pressurization on force coefficients for two different viscosity fluids. Results indicate an increase in stiffness and a decrease in damping when increasing the frequency of excitation. Damper cavity pressurization was shown to eliminate squeeze film cavitation for the vibration amplitudes and frequency range in the study. Additionally, the paper advances a transient fluid–structure interaction (FSI) analysis aimed at gaining insight on the interaction of flexible elements bounding a hermetic fluid volume experiencing sinusoidal vibratory motion. The analysis considers an idealized damper model with and without a vibration transmission post while varying diaphragm modulus of elasticity for three excitation frequencies. Computational results were able to capture the increase in stiffness and the decrease in damping and show that the flexibility of the bounding elements influence the damper cavity volume change and phase ultimately affecting dynamic cavity pressures and force coefficients.

References

References
1.
Kalra
,
C. J.
,
Hofer
,
D.
,
Sevincer
,
E.
,
Moore
,
J.
, and
Brun
,
K.
,
2014
, “
Development of High Efficiency Hot Gas Turbo-Expander for Optimized CSP Supercritical CO2 Power Block Operation
,” The Fourth International Symposium—Supercritical CO2 Power Cycles (sCO2), Pittsburgh, PA, Sept. 9–10, pp.
1
11
.
2.
Hofer
,
D.
,
2016
, “
sCO2 Power Cycle Path Forward
,”
IGTI Turbo Expo
,
Seoul, South Korea
,
June 13–17
.
3.
Ertas
,
B. H.
,
Delgado
,
A.
, and
Moore
,
J. J.
,
2017
, “
Dynamic Characterization of an Integral Squeeze Film Bearing Support Damper for a Super-Critical CO2 Expander
,”
ASME J. Eng. Gas Turbines Power
,
140
(
5
), p.
052501
.10.1115/1.4038121
4.
Ertas
,
B. H.
, and
Bidkar
,
R.
,
2017
, “
Apollo High Efficiency sCO2 Centrifugal Compressor Continuation Report, Section 7: Gas Bearing Design and Testing
,”.
5.
San Andres
,
L.
,
Chirathadam
,
T. A.
, and
Kim
,
T. H.
,
2010
, “
Measurement of Structural Stiffness and Damping Coefficients in a Metal Mesh Foil Bearing
,”
ASME J. Eng. Gas Turbines Power
,
132
(
3
), p.
032503
.10.1115/1.3159379
6.
Feng
,
K.
,
Liu
,
Y.
,
Zhao
,
X.
, and
Liu
,
W.
,
2015
, “
Experimental Evaluation of the Structure Characterization of a Novel Hybrid Bump-Metal Mesh Foil Bearing
,”
ASME J. Tribol.
,
138
(
2
), p.
021702
.10.1115/1.4031496
7.
Carpino
,
M.
, and
Peng
,
J.
,
1994
, “
Theoretical Performance of a Hydrostatic Foil Bearing
,”
ASME J. Tribol.
,
116
(
1
), pp.
83
89
.10.1115/1.2927051
8.
Kumar
,
M.
, and
Kim
,
D.
,
2008
, “
Parametric Studies on Dynamic Performance of Hybrid Airfoil Bearing
,”
ASME J. Eng. Gas Turbines Power
,
130
(
6
), p.
062501
.10.1115/1.2940354
9.
Ertas
,
H.
,
2011
, “
Compliant Hybrid Gas Journal Bearing Using Integral Wire Mesh Dampers
,” U.S. Patent No. 8083413 B2.
10.
Ertas
,
B. H.
,
2009
, “
Compliant Hybrid Journal Bearings Using Integral Wire Mesh Dampers
,”
ASME J. Eng. Gas Turbines Power
,
131
(
2
), p.
022503
.10.1115/1.2967476
11.
Ertas
,
B. H.
,
Camatti
,
M.
, and
Mariotti
,
G.
,
2010
, “
Synchronous Response to Rotor Imbalance Using a Damped Gas Bearing
,”
ASME J. Eng. Gas Turbines Power
,
132
(
3
), p.
032501
.10.1115/1.3157097
12.
Delgado
,
A.
,
2015
, “
Experimental Identification of Dynamic Force Coefficients for a 110 MM Compliantly Damped Hybrid Gas Bearing
,”
ASME J. Eng. Gas Turbines Power
,
137
(
7
), p.
072502
.10.1115/1.4029203
13.
Delgado
,
A. M.
,
Ertas
,
B. H.
,
Hallman
,
D. L.
, and
Smith
,
W. J.
,
2015
, “
Hermetically Sealed Damper Assembly and Methods of Assembling Same
,” U.S. Patent No. 9121448.
14.
Ertas
,
B. H.
,
Delgado
,
A. M.
,
Hallman
,
D. L.
, and
Smith
,
W. J.
,
2016
, “
Journal Bearing Assemblies and Methods of Assembling Same
,” U.S. Patent No. 9429191.
15.
Ertas
,
B.
, and
Delgado
,
A.
,
2018
, “
Hermetically Sealed Squeeze Film Damper for Operation in Oil-Free Environments
,”
ASME J. Eng. Gas Turbines Power
,
141
(
2
), p.
022503
.10.1115/1.4041520
16.
Ertas
,
B.
, and
Delgado
,
A.
,
2018
, “
Compliant Hybrid Gas Bearing Using Modular Hermetically Sealed Squeeze Film Dampers
,”
ASME J. Eng. Gas Turbines Power
,
141
(
2
), p.
022504
.10.1115/1.4041310
17.
Delgado
,
A.
, and
Ertas
,
B.
,
2018
, “
Dynamic Characterization of a Novel Externally Pressurized Compliantly Damped Gas-Lubricated Bearing With Hermetically Sealed Squeeze Film Dampers
,”
ASME J. Eng. Gas Turbines Power
,
141
(
2
), p.
021028
.10.1115/1.4041311
18.
Mook
,
T. J.
,
Ertas
,
B. H.
, and
Bellardi
,
J. J.
,
2017
, “
Bearing
,” U.S. Patent No. 9746029.
19.
Mook
,
J. T.
,
Ertas
,
B. H.
, and
Bellardi
,
J. J.
,
2018
, “
Gas Bearing
,” U.S. Patent No. 9951811.
20.
Ertas
,
B. H.
,
Mook
,
J. T.
, and
Bellardi
,
J. J.
,
2018
, “
Gas Distribution Labyrinth for a Bearing Pad
,” U.S. Patent No. 10001166.
21.
Ertas
,
B. H.
,
Mook
,
J. T.
, and
Bellardi
,
J. J.
,
2018
, “
Fluid Filled Damper for Gas Bearing Assembly
,” U.S. Patent No. 10,066,505.
22.
Ertas
,
B. H.
, and
Delgado
,
A. M.
,
2016
, “
Gas Bearing Having Integrally Formed Components
,” U.S. Patent No. 9416820.
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