Though many approaches have been proposed in the literature to model the reaction forces in a catcher bearing (CB), there are still phenomena observed in experimental tests that cannot be explained by existing models. The following paper presents a novel approach to model a CB system. Some of the elements in the model have been previously introduced in the literature; however, there are other elements in the proposed model that are new, providing an explanation for the forward whirling phenomena that has been observed repeatedly in the literature. The proposed CB model is implemented in a finite-element rotordynamic package, and nonlinear time-transient simulations are performed to predict published experimental results of a high-speed vertical subscale compressor; with no other forces present in the model, the agreement between simulations and experimental data is favorable. The results presented herein show that friction between the journal and axial face of the catcher bearing results in a forward cross-coupled force that pushes the rotor in the direction of rotation. This force is proportional to the coefficient of friction between the axial face of the rotor and catcher bearing and the axial thrust on the rotor. This force results in synchronous whirl when the running speed is below a combined natural frequency of the rotor-stator system and constant frequency whip when the speed is above a whip frequency.

References

References
1.
Maslen
,
E.
, and
Barrett
,
L.
,
1996
, “
Rotor Whirl in Compliant Auxiliary Bearings
,”
J. Vib. Control
,
2
(
2
), pp.
145
159
.10.1177/107754639600200202
2.
Schmied
,
J.
, and
Pradetto
,
J. C.
,
1992
, “
Behavior of a One Ton Rotor Being Dropped Into Auxiliary Bearings
,”
Third International Symposium on Magnetic Bearings, Alexandria, VA, July 29–31
.
3.
Caprio
,
M. T.
,
Murphy
,
B. T.
, and
Herbst
,
J. D.
,
2004
, “
Spin Commissioning and Drop Tests of a 130 kW-hr Composite Flywheel
,”
9th International Symposium on Magnetic Bearings
,
Lexington, KY
, August 3–6, Paper No. 65.
4.
Hawkins
,
L.
,
McMullen
,
P.
, and
Larsonneur
,
R.
,
2005
, “
Development of an AMB Energy Storage Flywheel for Commercial Application
,”
8th International Symposium on Magnetic Suspension Technology
,
Dresden, Germany, September 26–28
.
5.
McMullen
,
P.
,
Vuong
,
V.
, and
Hawkins
,
L.
,
2007
, “
Flywheel Energy Storage System With AMB's and Hybrid Backup Bearings
,”
10th International Symposium on Magnetic Bearings
,
Martigny, Switzerland, August 21–23, 2006
.
6.
Ransom
,
D.
,
Masala
,
A.
,
Moore
,
J.
,
Vannini
,
G.
, and
Camatti
,
M.
,
2008
, “
Numerical and Experimental Simulation of a Vertical High Speed Motorcompressor Rotor Drop Onto Catcher Bearings
,”
11th International Symposium on Magnetic Bearings
,
Nara, Japan
, August 26–29.
7.
Ransom
,
D.
,
Masala
,
A.
,
Moore
,
J.
,
Vannini
,
G.
,
Camatti
,
M.
, and
Lacour
,
M.
,
2009
, “
Development and Application of a Vertical High Speed Motor-Compressor Simulator for Rotor Drop Onto Auxiliary Bearings
,”
38th Turbomachinery Symposium
,
Houston, TX
, September 14–17.
8.
Masala
,
A.
,
Vannini
,
G.
,
Ransom
,
D.
, and
Moore
,
J.
,
2011
, “
Numerical Simulation and Full Scale Landing Test of a 12.5 MW Vertical Motorcompressor Levitated by Active Magnetic Bearings
,” ASME TurboExpo, Vancouver, Canada, June 6–10,
ASME
Paper No. GT2011-46411. 10.1115/GT2011-46411
9.
Wilkes
,
J.
,
Dyck
,
B. J.
,
Childs
,
D.
, and
Phillips
,
S.
,
2009
, “
The Numerical and Experimental Characteristics of Multi-Mode Dry-Friction Whip and Whirl
,”
ASME J. Eng. Gas Turbines Power
,
132
(
5
), p.
052503
.10.1115/1.3204658
10.
TAMU Turbomachinery Laboratory
,
2002
,
xltrc2 Brochure
,
TAMU Turbomachinery Laboratory
, College Station, TX.
11.
Lahriri
,
S.
,
Santos
,
I.
,
Weber
,
H.
, and
Hartmann
,
H.
,
2012
, “
On the Nonlinear Dynamics of Two Types of Backup Bearings—Theoretical and Experimental Aspects
,” ASME Turbo Expo, Copenhagen, Denmark, June 11–15,
ASME
Paper No. GT2012-68319. 10.1115/GT2012-68319
12.
Hunt
,
K. H.
, and
Crossley
,
F. R.
,
1975
, “
Coefficient of Restitution Interpreted as Damping in Vibroimpact
,”
ASME J. Appl. Mech.
,
42
, pp.
440
445
.10.1115/1.3423596
13.
Bartha
,
A. R.
,
1998
, “
Dry Friction Induced Backward Whirl: Theory and Experiment
,”
5th IFToMM Conference on Rotor Dynamics
,
Darmstadt, Germany, September 7–10, Vieweg, Braunschweig
, Germany, pp.
756
767
.
14.
Bartha
,
A. R.
,
2000
, “
Dry Friction Backward Whirl of Rotors
,” Ph.D. dissertation No. 13817, ETH Zürich, Zürich, Switzerland.
15.
Wilkes
,
J. C.
,
2008
, “
A Perspective on the Numerical and Experimental Characteristics of Multi-Mode Dry-Friction Whip and Whirl
,” M.S. thesis, Texas A&M University, College Station, TX.
16.
Childs
,
D. W.
, and
Bhattacharya
,
A.
,
2007
, “
Prediction of Dry-Friction Whirl and Whip Between a Rotor and a Stator
,”
ASME J. Vibr. Acoust.
,
129
, pp.
355
362
.10.1115/1.2731412
17.
Harris
,
T.
,
1984
,
Rolling Bearing Analysis
,
2nd ed.
,
Wiley
,
New York
, pp.
426
432
.
18.
Palmgren
,
A.
,
1959
,
Ball and Roller Bearing Engineering
,
3rd ed.
,
Burbank
,
Philadelphia
, pp.
34
41
.
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