Measurements of dynamic film pressures and high-speed photographs of the flow field in an open-ended Squeeze Film Damper (SFD) operating with natural free air entrainment are presented for increasing whirl frequencies (8.33–50 Hz), and a range of feed pressures to 250 kPa (37 psig). The flow conditions range from lubricant starvation (air ingestion) to a fully flooded discharge operation. The test dynamic pressures and video recordings show that air entrainment leads to large and irregular gas fingering and striation patterns. This is a natural phenomenon in SFDs operating with low levels of external pressurization (reduced lubricant through flow rates). Air ingestion and entrapment becomes more prevalent as the whirl frequency raises, and increasing the feed pressure aids little to ameliorate the loss in dynamic forced performance. As a result of the severity of air entrainment, experimentally estimated damping forces decrease steadily as the whirl frequency (operating speed) increases.

Issue Section:
Technical Papers
Keywords:
film flow, rotational flow, flow measurement, aerodynamics, machine bearings, turbines, damping, lubrication, cavitation
Topics:
Air entrainment, Dampers, Flow (Dynamics), Flow visualization, Lubricants, Pressure, Whirls, Damping, Cavitation, Film thickness
1.
San Andre´s, 2000, “Squeeze Film Dampers—Design and Operating Issues,” Class Notes on Modern Lubrication, Texas A&M University, College Station, TX.
2.
Diaz
,
S.
, and
San Andre´s
,
L.
,
2001
, “
A Model for Squeeze Film Dampers Operating with Air Entrainment and Validation with Experiments
,”
ASME J. Tribol.
,
123
(
1
), pp.
125
–
133
.
3.
Zeidan
,
F. Y.
, and
Vance
,
J. M.
,
1990
, “
Cavitation Regimes in Squeeze Film Dampers and Their Effect on the Pressure Distribution
,”
STLE Tribol. Trans.
,
33
, pp.
447
–
453
.
4.
Dowson, D., and Taylor, M. 1974, “Fundamental Aspects of Cavitation in Bearings,” Proceedings of the 1st Leeds-Lyon Symposium on Tribology, University of Leeds, England, pp. 15–28.
5.
Cole, J. A., and Hughes, C. J., 1957, “Visual Study of Film Extent in Dynamically Loaded Complete Journal Bearings,” Proc. Lub. Wear Conf., pp. 147–149.
6.
White, D. C., 1970, “Squeeze Film Journal Bearings,” Ph. D. Dissertation, Cambridge University.
7.
Marsh, H., 1974, “Cavitation in Dynamically Loaded Journal Bearings,” Proceedings of the 1st Leeds-Lyon Symposium on Tribology, University of Leeds, England, pp. 91–95.
8.
Bansal
,
P. N.
, and
Hibner
,
D. H.
,
1978
, “
Experimental and Analytical Investigation of Squeeze Film Bearing Damper Forces Induced by Offset Circular Whirl Orbits
,”
ASME J. Mech. Des.
,
100
, pp.
549
–
557
.
9.
Walton
,
J.
,
Walowit
,
E.
,
Zorzi
,
E.
, and
Schrand
,
J.
,
1987
, “
Experimental Observation of Cavitating Squeeze Film Dampers
,”
ASME J. Tribol.
,
109
, pp.
290
–
295
.
10.
Diaz
,
S.
, and
San Andre´s
,
L.
,
1997
, “
Measurements of Pressure in a Squeeze Film Damper with an Air/Oil Bubbly Mixture
,”
STLE Tribol. Trans.
,
41
(
2
), pp.
282
–
288
.
11.
Diaz
,
S.
, and
San Andre´s
,
L.
,
1998
, “
Reduction of the Dynamic Load Capacity in a Squeeze Film Damper Operating with a Bubbly Mixture
,”
ASME J. Eng. Gas Turbines Power
,
121
, pp.
703
–
709
.
12.
Diaz
,
S.
, and
San Andre´s
,
L.
,
2001
, “
Air Entrainment Versus Lubricant Vaporization in Squeeze Film Dampers
,”
ASME J. Eng. Gas Turbines and Power
,
123
(
4
), pp.
871
–
877
.
Copyright © 2003
 by ASME
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