Aircraft engine rotors, invariably supported on rolling element bearings with little damping, are particularly sensitive to rotor imbalance and sudden maneuver loads. Most engines incorporate squeeze film dampers (SFDs) as a means to dissipate mechanical energy from rotor motions and to ensure system stability. The paper experimentally quantifies the dynamic forced performance of two end sealed SFDs with dimensions and an operating envelope akin to those in actual jet engine applications. The current experimental results complement and extend prior research conducted with open ends SFDs (San Andrés, 2012, “Damping and Inertia Coefficients for Two Open Ends Squeeze Film Dampers With a Central Groove: Measurements and Predictions,” ASME J. Eng. Gas Turbines Power, 134, p. 102506). In the tests, two journals make for two SFD configurations, both with a diameter D = 127 mm and nominal radial film clearance c = 0.127 mm. One short length damper has film lands with extent L = 12.7 mm, while the other has 25.4 mm ( = 2L) land lengths. A central groove of length LG = L and depth at ¾ L separates the film lands. A light viscosity lubricant is supplied into the central groove via three orifices, 120 deg apart, and then flows through the film lands whose ends are sealed with tight piston rings. The oil pushes through the piston rings to discharge at ambient pressure. In the tests, a static load device pulls the damper structure to increasing eccentricities (maximum 0.38c) and external shakers exert single-frequency loads 50–250 Hz, inducing circular orbits with amplitudes equaling ∼5% of the film clearance. The lubricant feed and groove pressures and flow rates through the top and bottom film lands are recorded to determine the flow resistances through the film lands and the end seals. Measured dynamic pressures in the central groove are as large as those in the film lands, thus demonstrating a strong flow interaction, further intensified by the piston ring end seals which are effective in preventing side leakage. Dynamic pressures and reaction loads are substantially higher than those recorded with the open ends dampers. Comparisons to test results for two identical damper configurations but open ended (San Andrés, 2012, “Damping and Inertia Coefficients for Two Open Ends Squeeze Film Dampers With a Central Groove: Measurements and Predictions,” ASME J. Eng. Gas Turbines Power, 134, p. 102506) demonstrate at least a threefold increase in direct damping coefficients and no less than a double increment in added mass coefficients. Predictions from a physics-based model that includes the central groove, the lubricant feed holes, and the end seals' flow conductances are in agreement with the test results for the short length damper. For the long damper, the predicted damping coefficients are in good agreement with the measurements, while the added masses are under-predicted by ∼25%.

References

References
1.
Zeidan
,
F. Y.
,
San Andrés
,
L.
, and
Vance
,
J. M.
,
1996
, “
Design and Application of Squeeze Film Dampers in Rotating Machinery
,”
Proceedings of the 25th Turbomachinery Simposium,Turbomachinery Laboratory, Texas A&M University
,
Houston, TX
, September 16–19, pp.
169
188
.
2.
San Andrés
,
L.
,
2010
, “
Squeeze Film Dampers: Operation, Models and Technical Issues
,” Modern Lubrication Theory, Notes 13,
Texas A&M University Digital Libraries
, https://repository.tamu.edu/handle/1969.1/93197
3.
Della Pietra
,
L.
, and
Adiletta
,
G.
,
2002
, “
The Squeeze Film Damper Over Four Decades of Investigations. Part I: Characteristics and Operating Features
,”
Shock Vib. Dig.
,
34
(
1
), pp.
3
26
.
4.
Adiletta
,
G.
, and
Della Pietra
,
L.
,
2002
, “
The Squeeze Film Damper Over Four Decades of Investigations. Part II: Rotordynamic Analyses With Rigid and Flexible Rotors
,”
Shock Vib. Dig.
,
34
(
2
), pp.
97
126
.
5.
Gehannin
,
J.
, and
Arghir
,
M.
,
2010
, “
Complete Squeeze-Film Damper Analysis Based on the “Bulk Flow” Equations
,”
Tribol. Trans.
,
53
(
1
), pp.
84
96
.10.1080/10402000903226382
6.
Defaye
,
C.
,
Arghir
,
M.
, and
Bonneau
,
O.
,
2006
, “
Experimental Study of the Radial and Tangential Forces in a Whirling Squeeze Film Damper
,”
Tribol. Trans.
,
49
, pp.
271
278
.10.1080/05698190600614916
7.
San Andrés
,
L.
, and
Vance
,
J. M.
,
1987
, “
Experimental Measurement of the Dynamic Pressure Distribution in a Squeeze Film Damper Executing Circular Centered Orbits
,”
ASLE Trans.
,
30
(
3
), pp.
373
383
.10.1080/05698198708981770
8.
Ramli
,
M. D.
,
Roberts
,
J. B.
, and
Ellis
,
J.
,
1987
, “
The Determination of Squeeze Film Dynamic Coefficients From Experimental Transient Data
,”
ASME J. Tribol.
,
109
(
1
), pp.
155
163
.10.1115/1.3261308
9.
Arauz
,
G. L.
, and
San Andrés
,
L.
,
1996
, “
Experimental Study on the Effect of a Circumferential Feeding Groove on the Dynamic Force Response of a Sealed Squeeze Film Damper
,”
ASME J. Tribol.
,
118
(
4
), pp.
900
905
.10.1115/1.2831626
10.
Arauz
,
G. L.
, and
San Andrés
,
L.
,
1997
, “
Experimental Force Response of a Grooved Squeeze Film Damper
,”
Tribol. Int.
,
31
(
5
), pp.
265
270
.10.1016/0301-679X(96)00033-3
11.
Ramli
,
M. D.
,
Roberts
,
J. B.
, and
Ellis
,
J.
,
1996
, “
Force Coefficients for a Centrally Grooved Short Squeeze Film Damper
,”
ASME J. Tribol.
,
118
(
3
), pp.
608
616
.10.1115/1.2831580
12.
Qingchang
,
T.
,
Ying
,
C.
, and
Lyjiang
,
W.
,
1997
, “
Effect of a Circumferential Feeding Groove on Fluid Force in Short Squeeze Film Dampers
,”
Tribol. Int.
,
30
(
6
), pp.
409
416
.10.1016/S0301-679X(96)00071-0
13.
San Andrés
,
L.
,
1992
, “
Analysis of Short Squeeze Film Dampers With a Central Groove
,”
ASME J. Tribol.
,
114
(
4
), pp.
659
664
.10.1115/1.2920933
14.
Lund
,
J. W.
,
Myllerup
,
C. M.
, and
Hartmann
,
H.
,
2003
, “
Inertia Effects in Squeeze-Film Damper Bearings Generated by Circumferential Oil Supply Groove
,”
ASME J. Vibr. Acoust.
,
125
(
4
), pp.
495
499
.10.1115/1.1606711
15.
Kim
,
K. J.
, and
Lee
,
C. W.
,
2005
, “
Dynamic Characteristics of Sealed Squeeze Film Damper With a Central Feeding Groove
,”
ASME J. Tribol.
,
127
(
1
), pp.
103
111
.10.1115/1.1828075
16.
Childs
,
D. W.
,
Rodriguez
,
L. E.
,
Cullotta
,
V.
,
Al-Ghasem
,
A.
, and
Graviss
,
M.
,
2006
, “
Rotordynamic Coefficients and Static (Equilibrium Loci and Leakage) Characteristics for Short, Laminar-Flow Annular Seals
,”
ASME J. Tribol.
,
128
(
2
), pp.
378
387
.10.1115/1.2164468
17.
Childs
,
D. W.
,
Graviss
,
M.
, and
Rodriguez
,
L. E.
,
2007
, “
The Influence of Groove Size on the Static and Rotordynamic Characteristics of Short, Laminar-Flow Annular Seals
,”
ASME J. Tribol
,
129
(
2
), pp.
398
406
.10.1115/1.2647471
18.
Delgado
,
A.
, and
San Andrés
,
L.
,
2010
, “
A Model for Improved Prediction of Force Coefficients in Grooved Squeeze Film Dampers and Oil Seal Rings
,”
ASME J. Tribol.
,
132
(
3
), p.
032202
.10.1115/1.4001459
19.
San Andrés
,
L.
, and
Delgado
,
A.
,
2012
, “
A Novel Bulk-Flow Model for Improved Predictions of Force Coefficients in Grooved Oil Seals Operating Eccentrically
,”
ASME J. Eng. Gas Turbines Power
,
134
, p.
052509
.10.1115/1.4004736
20.
Delgado
,
A.
, and
San Andrés
,
L.
,
2010
, “
Identification of Force Coefficients in a Squeeze Film Damper With a Mechanical Seal: Large Contact Force
,”
ASME J. Tribol.
,
132
(
3
), p.
032201
.10.1115/1.4001458
21.
San Andrés
,
L.
,
2012
, “
Damping and Inertia Coefficients for Two Open Ends Squeeze Film Dampers With a Central Groove: Measurements and Predictions
,”
ASME J. Eng. Gas Turbines Power
,
134
, p.
102506
.10.1115/1.4007058
22.
San Andrés
,
L.
,
Jung
,
S. Y.
, and
Vance
,
J.
,
1991
, “
Measurements of Pressure Distributions in a Squeeze Film Damper—II: Partially Sealed Configuration
,”
STLE Tribol. Trans.
,
34
(
3
), pp.
383
389
.10.1080/10402009108982048
23.
San Andrés
,
L.
,
Meng
,
G.
, and
Vance
,
J.
,
1991
, “
Experimental Measurement of the Dynamic Pressure and Force Response of a Partially Sealed Squeeze Film Damper
,”
Proceedings of the 13th Biennial Conference on Mechanical Vibration and Noise
,
Miami, FL
, September 22–25, Rotating Machinery and Vehicle Dynamics, ASME, Vol. 35, pp.
251
256
.
24.
Chen
,
P. Y. P.
, and
Hahn
,
E. J.
,
2000
, “
Side Clearance Effects on Squeeze Film Damper Performance
,”
Tribol. Int.
,
33
(
3-4
), pp.
161
165
.10.1016/S0301-679X(00)00022-0
25.
Xing
,
C.
,
Braun
,
M. J.
, and
Li
,
H.
, “
Sealing Effect on the Performance of Squeeze Film Damper
,”
ASME
Paper No. GT2009-60204.10.1115/GT2009-60204
26.
Seshagiri
,
S.
,
2011
, “
Identification of Force Coefficients in Two Squeeze Film Dampers With a Central Groove
,” M.S. thesis, Texas A&M University, College Station, TX.
27.
Mahecha
,
P.
,
2011
, “
Experimental Dynamic Forced Performance of a Centrally Grooved, End Sealed Squeeze Film Damper
,” M.S. thesis, Texas A&M University, College Station, TX.
28.
Fritzen
,
C. P.
,
1986
, “
Identification of Mass, Damping and Stiffness Matrices of Mechanical Systems
,”
ASME J. Vib., Acoust., Stress, Reliab. Des.
,
108
, pp.
9
16
.10.1115/1.3269310
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