Gas foil bearings can operate in extreme conditions such as high temperature and high rotating speed, compared to traditional bearings. They also provide better damping and stability characteristics and have larger tolerance to debris and rotor misalignment. Gas foil bearings have been successfully applied to micro- and small-sized turbomachinery, such as microgas turbine and cryogenic turbo expander. In the last decades, a lot of theoretical and experimental work has been conducted to investigate the properties of gas foil bearings. However, very little work has been done to study the influence of the foil bearing pad configuration. This study proposes a robust approach to analyze the effect of the foil geometry on the performance of a six-pad thrust foil bearing. In this study, a three-dimensional (3D) computational fluid dynamics (CFD) model for a parallel six-pad thrust foil bearing is created. In order to predict the thermal property, the total energy with viscous dissipation is used. Based on this model, the geometry of the thrust foil bearing is parameterized and analyzed using the design of experiments (DOE) methodology. In this paper, the selected geometry parameters of the foil structure include minimum film thickness, inlet film thickness, the ramp extent on the inner circle, the ramp extent on the outer circle, the arc extent of the pad, and the orientation of the leading edge. The objectives in the sensitivity study are load capacity and maximal temperature. An optimal foil geometry is derived based on the results of the DOE process by using a goal-driven optimization technique to maximize the load capacity and minimize the maximal temperature. The results show that the geometry of the foil structure is a key factor for foil bearing performance. The numerical approach proposed in this study is expected to be useful from the thrust foil bearing design perspective.

References

References
1.
Branagan
,
M.
,
Griffin
,
D.
,
Goyne
,
C.
, and
Untaroiu
,
A.
,
2015
, “
Compliant Gas Foil Bearings and Analysis Tools
,”
ASME J. Eng. Gas Turbines Power
,
138
(5), p.
054001
.
2.
Heshmat
,
H.
,
Walowit
,
J. A.
, and
Pinkus
,
O.
,
1983
, “
Analysis of Gas Lubricated Compliant Thrust Bearings
,”
ASME J. Lubr. Technol.
,
105
(4), p.
054001
.
3.
Iordanoff
,
I.
,
1998
, “
Maximum Load Capacity Profiles for Gas Thrust Bearings Working Under High Compressibility Number Conditions
,”
ASME J. Tribol.
,
120
(
3
), pp.
571
576
.
4.
Heshmat
,
C. A.
,
David
,
S. X.
, and
Heshmat
,
H.
,
2000
, “
Analysis of Gas Lubricated Foil Thrust Bearings Using Coupled Finite Element and Finite Difference Methods
,”
ASME J. Tribol.
,
122
(1), pp.
199
204
.
5.
Dykas
,
B. D.
,
2006
, “
Factors Influencing the Performance of Foil Gas Thrust Bearings for Oil-Free Turbomachinery Applic
ations,”
Ph.D. Dissertation
, Case Western Reserve University, Cleveland, OH.https://www.researchgate.net/publication/282857790_Factors_Influencing_the_Performance_of_Foil_Gas_Thrust_Bearings_for_Oil-Free_Turbomachinery_Applications
6.
Dykas
,
B.
,
Christopher
,
J. P.
,
DellaCorte
., and
Bruckner
,
R.
,
2006
, “Thermal Management Phenomena in Foil Gas Thrust Bearings,”
ASME
Paper No. GT2006-91268.
7.
Dickman
,
J. R.
,
2010
, “
An Investigation of Gas Foil Thrust Bearing Performance and its
Influencing Factors,”
Master's thesis
, Case Western Reserve University, Cleveland, OH.https://etd.ohiolink.edu/!etd.send_file?accession=case1270153301&disposition=inline
8.
Bruckner
,
R. J.
,
2012
, “Performance of Simple Gas Foil Thrust Bearings in Air,” NASA Glenn Research Center, Cleveland, OH, Report No.
NASA/TM—2012-217262
.https://ntrs.nasa.gov/search.jsp?R=20120003368
9.
Andres
,
L. S.
,
Ryu
,
K.
, and
Diemer
,
P.
,
2014
, “
Prediction of Gas Thrust Foil Bearing Performance for Oil-Free Automotive Turbochargers
,”
ASME J. Eng. Gas Turbines Power
,
137
(3), p.
032502
.
10.
Kim
,
T. H.
, and
Lee
,
T. W.
,
2015
, “Design Optimization of Gas Foil Thrust Bearings for Maximum Load Capacity,”
ASME
Paper No. GT2015-43999.
11.
Ravikumar
,
R. N.
,
Rathanraj
,
K. J.
, and
ArunKumar
,
V.
,
2016
, “
Comparative Experimental Analysis of Load Carrying Capability of Air Foil Thrust Bearing for Different Configuration of Foil Assembly
,”
Proc. Technol.
,
25
, pp.
1096
1105
.
12.
Parka
,
D. J.
,
Kim
,
C. H.
,
Jang
,
G. H.
, and
Lee
,
Y. B.
,
2008
, “
Theoretical Considerations of Static and Dynamic Characteristics of Air Foil Thrust Bearing With Tilt and Slip Flow
,”
Tribol. Int.
,
41
(4), pp.
282
295
.
13.
Lee
,
D.
, and
Kim
,
D.
,
2011
, “
Design and Performance Prediction of Hybrid Air Foil Thrust Bearings
,”
ASME J. Eng. Gas Turbines Power
,
133
(4), p.
042501
.
14.
ANSYS, “ANSYS V16 Documentation, CFX Theory Guide 1.2.1,” ANSYS Inc., Canonsburg, PA.
15.
Hamrock
,
B. J.
,
Schmid
,
S. R.
, and
Jacobson
,
B. O.
,
2004
,
Fundamentals of Fluid Film Lubrication
,
CRC Press
, Boca Raton, FL.
16.
Kennard
,
R. W.
, and
Stone
,
L. A.
,
1969
, “
Computer Aided Design of Experiments
,”
Technometrics
,
11
(
1
), pp.
137
148
.
17.
Morgan
,
N. R.
,
Untaroiu
,
A.
,
Patrick
,
J.
, and
Wood
,
H. G.
,
2014
, “
Design of Experiments to Investigate Geometric Effects on Fluid Leakage Rate in a Balance Drum Seal
,”
ASME J. Eng. Gas Turbines Power
,
137
(
3
), p.
032501
.
18.
Migliorini
,
P. J.
,
Untaroiu
,
A.
, and
Wood
,
H. G.
,
2014
, “
A Numerical Study on the Influence of Hole Depth on the Static and Dynamic Performance of Hole-Pattern Seals
,”
ASME J. Tribol.
,
137
(
1
), p.
011702
.
19.
Untaroiu
,
A.
,
Liu
,
C.
,
Migliorini
,
P. J.
,
Wood
,
H. G.
, and
Untaroiu
,
C. D.
,
2014
, “
Hole-Pattern Seals Performance Evaluation Using Computational Fluid Dynamics and Design of Experiment Techniques
,”
ASME J. Eng. Gas Turbines Power
,
136
(
10
), p.
102501
.
20.
Fu
,
G.
, and
Untaroiu
,
A.
,
2016
, “An Optimum Design Approach for Textured Thrust Bearing With Elliptical-Shape Dimples Using CFD and DOE Including Cavitation,”
ASME
Paper No. IMECE2016-66971.
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