Compliant hybrid gas bearings (HGBs) combine key enabling features from both fixed geometry externally pressurized gas bearings and compliant foil bearings. The compliant hybrid bearing relies on both hydrostatic and hydrodynamic film pressures to generate load capacity and stiffness to the rotor system, while providing damping through integrally mounted metal mesh bearing support dampers. This paper presents experimentally identified force coefficients for a 110 mm compliantly damped gas bearing using a controlled-motion test rig. Test parameters include hydrostatic inlet pressure, excitation frequency, and rotor speed. The experiments were structured to evaluate the feasibility of implementing these bearings in large size turbomachinery. Dynamic test results indicate weak dependency of equivalent direct stiffness coefficients to most test parameters except for frequency and speed, where higher speeds and excitation frequency decreased equivalent bearing stiffness values. The bearing system equivalent direct damping was negatively impacted by increased inlet pressure and excitation frequency, while the cross-coupled force coefficients showed values an order of magnitude lower than the direct coefficients. The experiments also include orbital excitations to simulate unbalance response representative of a target machine while synchronously traversing a critical speed. The results indicate the gas bearing can accommodate vibration levels larger than the set bore clearance while maintaining satisfactory damping levels.

References

References
1.
Gross
,
W. A.
,
1962
,
Gas Film Lubrication
,
John Wiley and Sons, Inc.
,
New York
, pp.
3
, 279.
2.
Wade
,
J. L.
,
Lubell
,
D. R.
, and
Weissert
,
D.
,
2008
, “
Successful Oil-Free Version of a Gas Compressor Through Integrated Design of Foil Bearings
,”
ASME
Paper No. GT2008-50349.10.1115/GT2008-50349
3.
Agrawal
,
G.
,
1990
, “
Foil Gas Bearings for Turbomachinery
,”
SAE
Technical Paper No. 901236.10.4271/901236
4.
Mohawk Innovative Technology,
1998
, “
942 Pounds on a Film of Air!
,”
MiTi Developments
, Winter Technical Bulletin, Vol. 4. Mohawk Innovative Technology Inc., Albany, NY, available at: http://www.nano-nano.cc/newsletters.html
5.
DellaCorte
,
C.
, and
Bruckner
,
R.
,
2010
, “
Remaining Technical Challenges and Future Plans for Oil-Free Turbomachinery
,”
ASME J. Eng. Gas Turbines Power
,
133
(
4
), p.
042502
.10.1115/1.4002271
6.
San Andrés
,
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
7.
San Andrés
,
L.
, and
Chirathadam
,
T.
,
2012
, “
A Metal Mesh Foil Bearing and a Bump-Type Foil Bearing: Comparison of Performance for Two Similar Size Gas Bearings
,”
ASME J. Eng. Gas Turbines Power
,
134
(
10
), p.
102501
.10.1115/1.4007061
8.
De Santiago
,
O.
, and
Solórzano
,
V.
,
2013
, “
Experiments With Scaled Foil Bearings is a Test Compressor Rotor
,”
ASME
Paper No. GT2013-94087.10.1115/GT2013-94087
9.
Zhu
,
X.
, and
San Andrés
,
L.
,
2007
, “
Rotordynamic Performance of Flexure Pivot Hydrostatic Gas Bearings for Oil-Free Turbomachinery
,”
ASME J. Eng. Gas Turbines Power
,
129
(
4
), pp.
1020
1027
.10.1115/1.2720518
10.
San Andrés
,
L.
, and
Ryu
,
K.
,
2008
, “
Flexure Pivot Tilting Pad Hybrid Gas Bearings: Operation With Worn Clearances and Two Load-Pad Configurations
,”
ASME J. Eng. Gas Turbines Power
,
130
(
4
), p.
042506
.10.1115/1.2800346
11.
San Andrés
,
L.
, and
Ryu
,
K.
,
2008
, “
Hybrid Gas Bearings With Controlled Supply Pressure to Eliminate Rotor Vibrations While Crossing System Critical Speeds
,”
ASME J. Eng. Gas Turbines Power
,
130
(
6
), p.
062505
.10.1115/1.2966391
12.
Kim
,
D.
, and
Lee
,
D.
,
2010
, “
Design of Three-Pad Hybrid Air Foil Bearing and Experimental Investigation on Static Performance at Zero Running Speed
,”
ASME J. Eng. Gas Turbine Power
,
132
(
12
), p.
122504
.10.1115/1.4001066
13.
Wang
,
Y. P.
, and
Kim
,
D.
,
2013
, “
Experimental Identification of Force Coefficients of Large Hybrid Air Foil Bearings
,”
ASME
Paper No. GT2013-95765.10.1115/GT2013-95765
14.
Morosi
,
S.
, and
Santos
, I,
F.
,
2012
, “
Experimental Investigations of Active Air Bearings
,”
ASME
Paper No. GT2012-68766.10.1115/GT2012-68766
15.
Ertas
,
B.
,
2009
, “
Compliant Hybrid Journal Bearings Using Integral Wire Mesh Dampers
,”
ASME J. Eng. Gas Turbines Power
,
131
(
2
), p.
022503
.10.1115/1.2967476
16.
Ertas
,
H.
,
2011
, “
Compliant Hybrid Gas Journal Bearing Using Integral Wire Mesh Dampers
,” U.S. Patent No. 8083413 B2.
17.
Ertas
,
B.
,
Camatti
,
M.
, and
Mariotti
,
G.
,
2009
, “
Synchronous Response to Rotor Imbalance Using a Damped Gas Bearing
,”
ASME J. Eng. Gas Turbines Power
,
132
(
3
), p.
032501
.10.1115/1.3157097
18.
Glienicke
,
J.
,
1966
, “
Experimental Investigation of Stiffness and Damping Coefficients of Turbine Bearings and Their Application to Instability Predictions
,”
Proc. Inst. Mech. Eng., IMechE Conf.
,
181
(
2
), pp.
116
129
.10.1243/PIME_CONF_1966_181_038_02
19.
Childs
,
D.
, and
Hale
,
K.
,
1994
, “
A Test Apparatus and Facility to Identify the Rotordynamic Coefficients of High-Speed Hydrostatic Bearings
,”
ASME J. Tribol.
,
116
(
2
), pp.
337
334
.10.1115/1.2927226
20.
Delgado
,
A.
,
Vannini
,
G.
,
Ertas
,
B.
,
Drexel
,
M.
, and
Naldi
,
L.
,
2011
, “
Identification and Prediction of Force Coefficients in a Five Pads and Four Pads Tilting Pad Bearing for Load on Pad and Load Between Pad Configuration
,”
ASME J. Eng. Gas Turbines Power
,
133
(
9
), p.
092503
.10.1115/1.4002864
21.
Delgado
,
A.
,
Ertas
,
B.
,
Drexel
,
M.
,
Naldi
,
L.
, and
Vannini
,
G.
,
2010
, “
A Component Level Test Rig for Dynamic Characterization of Oil Lubricated Bearings Using Different Input Excitations
,”
International Symposium on Transport Phenomena and Dynamics of Rotating
(
ISROMAC-13
),
Honolulu, HI
, Apr. 4–7, Paper No. ISROMAC13–2010-TS60.20207.
22.
Pan
,
C. H. T.
,
1980
, “
Gas Bearings
,”
Tribology: Friction, Lubrication and Wear
,
Hemisphere Publishing Corp.
,
Washington, DC
.
23.
Ertas
,
B.
, and
Vance
,
J.
,
2006
, “
The Influence of Same-Sign Cross-Coupled Stiffness on Rotordynamics
,”
ASME J. Vib. Acoust.
,
129
(
1
), pp.
24
31
.10.1115/1.2346690
24.
American Petroleum Institute
,
1996
, “
Tutorial on the API Standard Paragraphs Covering Rotor Dynamics and Balancing: An Introduction to Lateral Critical and Train Torsional Analysis and Rotor Balancing
,”
American Petroleum Institute
, Washington, DC, API Publlication 684.
You do not currently have access to this content.